CN103852285A - Recognition method for problematic cable loads through generalized displacement and cable force monitoring - Google Patents

Abstract

Generalized displacement cable force monitoring problem The cable load identification method is based on cable force monitoring. By monitoring the generalized displacement of the support, the temperature of the cable structure and the ambient temperature, it is determined whether it is necessary to update the mechanical calculation benchmark model of the cable structure. The mechanical calculation benchmark model of the cable structure at the structural temperature and the ambient temperature, on the basis of this model, the numerical change matrix of the monitored quantity per unit damage is calculated. According to the approximate linear relationship between the current numerical vector of the monitored quantity and the current initial numerical vector of the monitored quantity, the numerical change matrix of the monitored quantity per unit damage, and the current nominal damage vector of the assessed object to be calculated, the value of the current nominal damage vector of the assessed object is calculated. According to the non-inferior solution, when there is a generalized displacement of the support and temperature changes, the influence of interference factors can be eliminated, and the load variation and problem cables can be identified.

Description

Cable Load Identification Method for Generalized Displacement Cable Force Monitoring Problem

technical field

Cable-stayed bridges, suspension bridges, truss structures and other structures have one thing in common, that is, they have many parts that bear tensile loads, such as cable-stayed cables, main cables, slings, tie rods, etc. , cables, or rods that only bear tensile loads are supporting components. For the sake of convenience, this method expresses this type of structure as The rods under tension or axial compression loads (also known as two-force rods) are collectively referred to as "cable systems" for convenience, and the term "supporting cables" is used in this method to refer to bearing cables, bearing cables and A member that bears axial tension or axial compression load is sometimes referred to as a "cable", so when the word "cable" is used later, it actually refers to a two-force member for a truss structure. The damage and slack of supporting cables is a major threat to the safety of cable structures. In this method, damaged cables and slack cables are collectively referred to as supporting cables with health problems, referred to as problem cables for short. During the service process of the structure, the correct identification of the health state of the supporting cables or the cable system is related to the safety of the entire cable structure. When the ambient temperature changes, the temperature of the cable structure will generally change accordingly. When the temperature of the cable structure changes, the support of the cable structure may undergo a generalized displacement, and the load on the cable structure may also change. The state of health may also be changing, and under such complex conditions, the method is based on cable force monitoring (this method refers to the monitored cable force as the "monitored quantity") to identify problem cables and changes in the loads on the cable structure It belongs to the field of engineering structure health monitoring.

Background technique

It is an urgent problem to be solved at present to eliminate the influence of load change, generalized displacement of cable structure support and structural temperature change on the identification results of the health state of the cable structure, so as to accurately identify the change of the health state of the structure; , the impact of the generalized displacement of the cable structure support and the change of the structural health state on the identification results of the variation of the load on the structure are also of great significance to the safety of the structure. This method discloses an effective method to solve these two problems.

Contents of the invention

Technical problem: This method discloses a method that realizes two functions that cannot be possessed by existing methods, namely, 1. When the support has a generalized displacement, when the load on the structure and the temperature of the structure (environment) change , it can eliminate the influence of support generalized displacement, load change and structure temperature change on the identification results of cable structure health status, so as to accurately identify the health status of support cables; The change of the load is identified, that is, the method can eliminate the influence of the generalized displacement of the support, the temperature change of the structure and the change of the health state of the support cable, and realize the correct identification of the load change degree.

Technical solution: In this method, "support space coordinates" refers to the coordinates of the support on the X, Y, and Z axes of the Cartesian coordinate system, and can also be said to be the space of the support on the X, Y, and Z axes. Coordinates, the specific value of the spatial coordinate of the support about a certain axis is called the spatial coordinate component of the support about the axis. In this method, a spatial coordinate component of the support is also used to express the specific value of the spatial coordinate of the support about a certain axis. Numerical value; use "support angular coordinates" to refer to the angular coordinates of the support with respect to the X, Y, and Z axes, and the specific value of the angular coordinates of the support with respect to a certain axis is called the angular coordinate component of the support with respect to the axis. In this method An angular coordinate component of the support is also used to express the specific value of the angular coordinate of the support with respect to a certain axis; the "generalized coordinate of the support" is used to refer to the angular coordinates of the support and the space coordinates of the support as a whole. In this method, the support's A generalized coordinate component expresses the specific value of the space coordinate or angular coordinate of the support about an axis; the change of the coordinate of the support about the X, Y, and Z axes is called the line displacement of the support, and it can also be said that the change of the space coordinate of the support is called is the linear displacement of the support. In this method, a linear displacement component of the support is also used to express the specific value of the linear displacement of the support about a certain axis; the change of the angular coordinates of the support about the X, Y, and Z axes is called the support Angular displacement, in this method, an angular displacement component of the support is also used to express the specific value of the angular displacement of the support with respect to a certain axis; the generalized displacement of the support refers to the overall displacement of the support line and the angular displacement of the support, and this method also uses A generalized displacement component of the support expresses the specific value of the linear displacement or angular displacement of the support about a certain axis; the linear displacement of the support can also be called translational displacement, and the settlement of the support is the linear displacement or translational displacement of the support in the direction of gravity portion.

The external force borne by objects and structures can be called load, and the load includes surface load and body load. Surface load, also known as surface load, is a load acting on the surface of an object, including concentrated load and distributed load. Body load is the load continuously distributed at various points inside the object, such as the object's own weight and inertial force.

Concentrated load is divided into concentrated force and concentrated force couple. In a coordinate system, such as a Cartesian rectangular coordinate system, a concentrated force can be decomposed into three components. Similarly, a concentrated force couple can also be decomposed into three components. If the load is actually a concentrated load, a concentrated force component or a concentrated force couple component is called a load in this method, and the change of the load at this time is embodied as a change of a concentrated force component or a concentrated force couple component.

Distributed load is divided into line distributed load and surface distributed load. The description of distributed load includes at least the action area of distributed load and the size of distributed load. , sine function and other distribution characteristics) and amplitude (for example, two distributed loads are uniformly distributed, but their amplitudes are different, uniform pressure can be used as an example to illustrate the concept of amplitude: the same structure bears two different loads Uniformly distributed pressure, both distributed loads are uniformly distributed loads, but the amplitude of one distributed load is 10MPa, and the amplitude of the other distributed load is 50MPa). If the load is actually a distributed load, when this method talks about the change of the load, it actually refers to the change of the amplitude of the distribution concentration of the distributed load, while the action area of the distributed load and the distribution characteristics of the distribution concentration remain unchanged. In the coordinate system, a distributed load can be decomposed into several components. If the amplitudes of the respective distribution concentration of several components of the distributed load change, and the ratios of the changes are not all the same, then in this method, the Several distributed load components are regarded as the same number of independent distributed loads. At this time, one load represents a distributed load component, and the components with the same amplitude change ratio of the distribution concentration can also be combined into a distributed load or called for a load.

Body load is the load continuously distributed at various points inside the object, such as the self-weight and inertial force of the object. The description of the body load includes at least the action area of the body load and the size of the body load. The size of the body load is expressed by the degree of distribution, and the distribution Concentration is expressed by distribution characteristics (such as distribution characteristics such as uniform distribution and linear function) and amplitude (for example, two body loads are uniformly distributed, but their amplitudes are different. The concept of amplitude can be illustrated by self-weight as an example: the same The two parts of a structure are made of different materials and therefore have different densities, so although the body loads on both parts are uniformly distributed, the magnitude of the body load on one part may be 10kN/m ³ and the other may be A part is subjected to a body load of magnitude 50kN/m ³ ). If the load is actually a body load, what is actually dealt with in this method is the change in the magnitude of the distribution concentration of the body load, while the action area of the body load and the distribution characteristics of the distribution concentration remain unchanged. At this time, in this method When referring to the change of the load in , it actually refers to the change of the magnitude of the distribution concentration of the body load. At this time, the changed load refers to the body load whose distribution concentration changes. In the coordinate system, a body load can be decomposed into several components (for example, in the Cartesian coordinate system, the body load can be decomposed into components about the three axes of the coordinate system, that is, in the Cartesian coordinate system body load can be decomposed into three components), if the amplitudes of the respective distribution concentration of several components of the body load change, and the ratios of changes are not all the same, then in this method, the The components are regarded as the same number of independent loads, and the body load components with the same amplitude change ratio of the distribution concentration can also be synthesized into a body load or called a load.

When the load is embodied as concentrated load, in this method, "load unit change" actually refers to "unit change of concentrated load", similarly, "load change" specifically refers to "change in magnitude of concentrated load", " "Load change" specifically refers to "the change in the size of the concentrated load", "the degree of load change" specifically refers to the "change degree of the concentrated load", and "the actual change in the load" refers to the "actual change in the size of the concentrated load". Amount", "changed load" refers to "concentrated load whose size changes". Simply put, at this time, "a certain change in a certain load" refers to "a certain change in the size of a certain concentrated load".

When the load is embodied as a distributed load, in this method, "the unit change of the load" actually refers to "the unit change of the amplitude of the distribution concentration of the distributed load", and the distribution characteristics of the distributed load are unchanged, similar to The "load change" specifically refers to "the change in the magnitude of the distribution concentration of the distributed load", while the distribution characteristics of the distributed load are unchanged, and the "load change" specifically refers to the "magnitude of the distribution concentration of the distributed load". The change amount of the load", "the degree of load change" specifically refers to the "change degree of the amplitude of the distribution concentration of the distributed load", and the "actual change of the load" specifically refers to the "actual change of the amplitude of the distribution concentration of the distributed load ", "changed load" refers to "distributed load whose amplitude of distribution intensity changes". A certain change in the amplitude of the load", while the distribution characteristics of the action area and distribution concentration of all distributed loads remain unchanged.

When the load is embodied as body load, in this method, "load unit change" actually refers to "unit change in the amplitude of distribution concentration of body load", similarly, "load change" means "body load The change of the magnitude of the distribution concentration of the body load", the "load change" refers to the "change of the magnitude of the distribution concentration of the body load", and the "load change degree" refers to the "magnitude of the distribution concentration of the body load The degree of change", "the actual change of the load" refers to the "actual change of the magnitude of the distribution concentration of the body load", and "the changed load" refers to the "body load whose distribution concentration changes. ", simply put, "a certain change in a certain load" refers to "a certain change in the magnitude of the distribution concentration of a certain body load", and the distribution characteristics of the action area and distribution concentration of all body loads are Changeless.

This method specifically includes:

a. For the convenience of description, this method collectively refers to the evaluated supporting cables and loads as the evaluated objects, and the sum of the number of evaluated supporting cables and the number of loads is N, that is, the number of evaluated objects is N; determine The numbering rule of the evaluated object. According to this rule, all the evaluated objects in the index structure will be numbered. This number will be used to generate vectors and matrices in the subsequent steps; this method uses the variable k to represent this number, k=1,2 ,3,...,N; Suppose there are M ₁ supporting cables in the cable system, the cable force data of the cable structure includes the cable force of these M ₁ supporting cables, obviously M ₁ is smaller than the number N of the evaluated objects; only through M ₁ It is impossible to solve the unknown state of N evaluated objects with M ₁ cable force data of supporting cables. This method artificially adds M ₂ cables to the cable structure on the basis of monitoring all M ₁ supporting cable forces. , called sensing cables, will monitor the cable forces of the newly added M ₂ sensing cables during the cable structure health monitoring; based on the above-mentioned monitored quantities, the entire cable structure has a total of M cable forces of M cables to be monitored , that is, there are M monitored quantities, where M is the sum of M ₁ and M ₂ ; M should be greater than the number N of objects to be evaluated; the stiffness of the newly added M ₂ sensing cables is the same as any supporting cable of the cable structure should be much smaller than the stiffness of the cable structure; the cable force of each sensor cable of the newly added M ₂ sensor cables should be much smaller than the cable force of any supporting cable of the cable structure, so that it can be guaranteed that even if the newly added The damage or relaxation of the M ₂ sensing cables has little effect on the stress, strain, and deformation of other components of the cable structure; the normal stress on the cross-section of the newly added M ₂ sensing cables should be less than its fatigue limit. It is required to ensure that the newly added M ₂ sensing cables will not suffer from fatigue damage; the two ends of the newly added M ₂ sensing cables should be fully anchored to ensure that there will be no slack; the newly added M ₂ sensing cables should be Get sufficient anti-corrosion protection to ensure that the newly added _M2 sensing cables will not be damaged or loosened; for convenience, in this method, "all monitored parameters of the cable structure" are referred to as "monitored quantities"; Continuously number the M monitored quantities, this method uses the variable j to represent this number, j=1,2,3,...,M, this number will be used to generate vectors and matrices in subsequent steps; in this method The newly added M ₂ sensing cables are part of the cable structure. When referring to the cable structure later, the cable structure includes the cable structure before adding the M ₂ sensing cables and the newly added M ₂ sensing cables. That is to say, when referring to the cable structure later on, it refers to the cable structure including the newly added M ₂ sensing cables; When the cable structure includes newly added M ₂ sensing cables, the obtained "cable structure steady-state temperature data" includes the newly added steady-state temperature data of M ₂ sensing cables, and the newly added The method for obtaining the steady-state temperature data of the M ₂ sensing cables is the same as the method for obtaining the steady-state temperature data of the M ₁ supporting cables in the cable structure, and will not be explained one by one in the following text; The method for measuring the cable force of the newly added M ₂ sensing cables is the same as the method for measuring the cable force of the M ₁ supporting cables of the cable structure, and will not be explained one by one in the following text; During the measurement, the same measurement is carried out on the newly added M ₂ sensing cables at the same time, which will not be explained one by one in the following; except that the newly added M ₂ sensing cables do not occur damage and relaxation, the newly added M The information requirements and acquisition methods of the _two sensing cables are the same as the information requirements and acquisition methods of the supporting cables of the cable structure, and will not be explained one by one in the following; when establishing various mechanical models of the cable structure in the following , treat the newly added M ₂ sensing cables as the supporting cables of the cable structure; in the following, except for the occasions of damage and slack of the supporting cables, when referring to the supporting cables, the mentioned supporting cables include cable The support cables of the structure and the newly added _M2 sensing cables; the time interval between any two measurements of the same quantity in real time monitoring in this method shall not be greater than 30 minutes, and the time of measuring and recording data is called the actual recording data time The external force borne by objects and structures can be called load, and load includes surface load and body load; surface load is also called surface load, which is a load acting on the surface of an object, including concentrated load and distributed load; body load is continuously distributed in The load of each point inside the object, including the self-weight and inertial force of the object; the concentrated load is divided into two types: concentrated force and concentrated force couple. In the coordinate system including the Cartesian coordinate system, a concentrated force can be decomposed into three Similarly, a concentrated force couple can also be decomposed into three components. If the load is actually a concentrated load, a concentrated force component or a concentrated force couple component is counted or counted as a load in this method. At this time, the load The change of the distributed load is embodied as a concentrated force component or a concentrated force couple component; distributed load is divided into line distributed load and surface distributed load, and the description of distributed load includes at least the action area of distributed load and the size of distributed load Expressed by distribution intensity, distribution intensity is expressed by distribution characteristics and amplitude; if the load is actually a distributed load, when this method talks about the change of load, it actually refers to the change of the amplitude of the distribution intensity of the distributed load, However, the distribution characteristics of the action area and distribution intensity of all distributed loads remain unchanged; in a coordinate system including the Cartesian coordinate system, a distributed load can be decomposed into three components, if the three components of the distributed load If the magnitude of the respective distribution concentration of the components changes, and the rate of change is not all the same, then in this method, the three components of the distributed load are counted or counted as three distributed loads, and one load represents A component of distributed load; body load is the load that is continuously distributed at various points inside the object. The description of body load includes at least the area of action of body load and the size of body load. The size of body load is expressed by the degree of distribution, and the degree of distribution Expressed by distribution characteristics and amplitude; if the load is actually a volume load, what is actually dealt with in this method is the change of the amplitude of the distribution concentration of the body load, while the action area of all body loads and the distribution characteristics of the distribution concentration In this case, the change of the load mentioned in this method actually refers to the change of the magnitude of the distribution concentration of the body load. At this time, the changed load refers to the magnitude of the distribution concentration Body loads that change; in a coordinate system including Cartesian coordinates, a body load can be decomposed into three components, if the magnitude of the distribution of the three components of the body load changes, and the rate of change is not all the same, then in this method, the three components of the body load are counted or counted as three distributed loads;

b. This method defines "the temperature measurement and calculation method of the cable structure of this method" according to steps b1 to b3;

b1: Query or measure the temperature-dependent heat transfer parameters of the composition materials of the cable structure and the environment where the cable structure is located, use the design drawings, as-built drawings of the cable structure, and the geometrically measured data of the cable structure, and use these data and parameters to establish a cable structure. The heat transfer calculation model of the structure; query the meteorological data of not less than 2 years in recent years where the cable structure is located, and count the number of cloudy days during this period as T cloudy days. In this method, the number of cloudy days that cannot be seen during the day The whole day of the sun is called a cloudy day, and the highest and lowest temperature between 0:00 and 30 minutes after the sunrise time of the next day on each of the T cloudy days is counted. The meteorological sunrise time determined by the sun and the revolution law does not mean that the sun can be seen on that day. You can check the data or calculate the required daily sunrise time through conventional meteorological calculations. Every cloudy day from 0:00 to 19:00 The maximum temperature difference between the highest temperature and the lowest temperature within 30 minutes after sunrise of the next day is called the maximum temperature difference of the daily temperature of the cloudy day. If there are T cloudy days, there will be the maximum temperature difference of the daily temperature of T cloudy days. Take T The maximum value of the maximum temperature difference of daily air temperature in a cloudy day is the reference daily temperature difference, which is recorded as ΔT _r ; query the location of the cable structure and the altitude interval of not less than 2 years of meteorological data in recent years or obtain the cable structure from actual measurements The change data and change law of the temperature of the environment with time and altitude, and the maximum change rate ΔT of the temperature of the environment where the cable structure is located with respect to the altitude in recent years for the location of the cable structure and the altitude interval of not less than 2 years in recent years _h , for the convenience of description, the unit of ΔT _h is ℃/m; take "R cable structure surface points" on the surface of the cable structure, and the specific principle of taking "R cable structure surface points" is described in step b3, and later The temperature of the surface points of the R cable structures will be obtained through actual measurement, and the temperature data obtained from the actual measurement is called "the measured data of the surface temperature of the R cable structures". The temperature of the surface points of the R cable structures is called the calculated temperature data as "calculation data of the surface temperature of the R cable structures"; For less than three different altitudes, at each selected altitude, at least two points are selected at the intersection of the horizontal plane and the surface of the cable structure, and the outer normal of the surface of the structure is indexed from the selected point, all selected The outer normal direction is called "the direction of measuring the temperature distribution of the cable structure along the wall thickness". The direction of temperature distribution along the wall thickness must include the outer normal direction of the sunny surface of the cable structure and the outer normal direction of the shaded surface of the cable structure, and the temperature distribution along the wall thickness of each measurement cable structure is uniform in the cable structure. Select no less than three points, measure the temperature of all selected points, the measured temperature is called "the temperature distribution data of the cable structure along the thickness", in which , "Measuring the direction of the temperature distribution of the cable structure along the wall thickness" measurement obtained "The temperature distribution data of the cable structure along the thickness" is called "the temperature distribution data of the cable structure along the thickness at the same altitude" in this method. It is assumed that H different altitudes are selected, and at each altitude, a In the direction of temperature distribution of B measuring cable structures along the wall thickness, E points are selected in the cable structure along the direction of temperature distribution of each measuring cable structure along the wall thickness, where H and E are not less than 3, and B is not less than 2. Let HBE be the product of H, B and E, corresponding to a total of HBE "points for measuring the temperature distribution data of the cable structure along the thickness", which will be obtained through actual measurement later. The measured temperature data is called "HBE cable structure measured temperature data along the thickness", if the heat transfer calculation model of the cable structure is used, the HBE measured cable structure along the thickness can be obtained through heat transfer calculation The temperature at the point of the temperature distribution data is called the calculated temperature data as "HBE cable structure temperature calculation data along the thickness"; let BE be the product of B and E, in this method, there is a total of BE "Temperature distribution data along the thickness of the cable structure at the same altitude"; select a location at the location of the cable structure according to the meteorological temperature measurement requirements, and obtain the actual temperature of the environment where the cable structure meets the meteorological temperature measurement requirements at this location; Select a location in the open and unsheltered place where the cable structure is located. This location should be able to get the fullest sunshine of the day that the location can get every day of the year, and place a carbon steel plate at this location. , called the reference plate. The reference plate cannot be in contact with the ground. The reference plate is no less than 1.5 meters away from the ground. One side of the reference plate faces the sun, which is called the sunny side. The sunny side of the reference plate is rough and dark. The reference plate The sunny side of the reference plate should be able to get the fullest sunshine of the day that a slab can get in that place every day of the year. The non-sunny side of the reference slab is covered with thermal insulation materials, and the slab’s sunny side will be obtained through real-time monitoring. surface temperature;

b2: Obtain the measured surface temperature data of the R cable structures at the surface points of the above R cable structures through real-time monitoring, and at the same time obtain the temperature distribution data of the previously defined cable structures along the thickness through real-time monitoring. The temperature data of the environment where the structure is located; through real-time monitoring, the temperature measured data series of the environment where the cable structure is located is obtained from the sunrise time of the day to 30 minutes after the sunrise time of the next day. The measured temperature data of the environment where the cable structure is located between the time and 30 minutes after sunrise of the next day are arranged in chronological order, and the highest temperature and the lowest temperature in the air temperature measurement data sequence of the environment where the cable structure is located are found. The maximum temperature difference in the air temperature measured data sequence minus the minimum temperature is the maximum temperature difference between the sunrise time of the day and 30 minutes after the sunrise time of the next day in the environment where the cable structure is located, which is called the maximum temperature difference of the environment, and is recorded as ΔT _emax ; The temperature measured data sequence of the environment where the cable structure is located is obtained through conventional mathematical calculations. The measured data series of the temperature of the sunny side of the reference plate between 30 minutes, the measured data series of the temperature of the sunny side of the reference plate from the sunrise time of the current day to the sunny side of the reference plate 30 minutes after the sunrise time of the next day The measured data of the temperature of the reference plate are arranged in chronological order, find the highest temperature and the lowest temperature in the measured data sequence of the temperature of the sunny side of the reference plate, and subtract the lowest temperature from the highest temperature in the measured data sequence of the temperature of the sunny side of the reference plate Temperature obtains the maximum temperature difference between the sunrise time of the day and 30 minutes after the sunrise time of the next day from the temperature of the sunny side of the reference plate, which is called the maximum temperature difference of the reference plate, and is recorded as ΔT _pmax ; The measured data series of cable structure surface temperature of all R cable structure surface points between 30 minutes after the sunrise time of the next day, there are R cable structure surface temperature measured data sequences of R cable structure surface points, each cable structure The measured data sequence of the surface temperature is arranged in chronological order by the measured data of the surface temperature of the cable structure between the sunrise time of the day and 30 minutes after the sunrise time of the next day at a surface point of the cable structure, and the measured data sequence of the surface temperature of each cable structure is found From the highest temperature and the lowest temperature in the data series, subtract the lowest temperature from the highest temperature in the measured data series of the surface temperature of each cable structure to obtain the temperature of each cable structure surface point from the sunrise time of the day to 30 minutes after the sunrise time of the next day If there are R surface points of the cable structure, there are R maximum temperature difference values between the sunrise time of the day and 30 minutes after the sunrise time of the next day, and the maximum value is called the maximum temperature difference of the cable structure surface, which is denoted as ΔT _smax ; From the measured data sequence of the surface temperature of each cable structure, the rate of change of the temperature of each cable structure surface point with respect to time is obtained through conventional mathematical calculations, and the temperature of each cable structure surface point with respect to time The rate of change also changes with time; after obtaining HBE "temperature distribution data along the thickness of the cable structure" at the same time between the sunrise time of the day and 30 minutes after the sunrise time of the next day through real-time monitoring, calculate the The difference between the maximum temperature and the minimum temperature in a total of BE "temperature distribution data of the cable structure along the thickness at the same altitude" at a selected altitude, the absolute value of this difference is called "thickness direction of the cable structure at the same altitude". If H different altitudes are selected, there will be H "maximum temperature differences in the thickness direction of the cable structure at the same altitude", and the maximum value of the H "maximum temperature differences in the thickness direction of the cable structure at the same altitude" is "The maximum temperature difference in the thickness direction of the cable structure", denoted as ΔT _tmax ;

b3: Measurement and calculation to obtain the steady-state temperature data of the cable structure; firstly, determine the moment to obtain the steady-state temperature data of the cable The time of the structural steady-state temperature data is between the sunset time of the current day and 30 minutes after the sunrise time of the next day. The sunset time refers to the meteorological sunset time determined according to the laws of the earth's rotation and revolution. You can query the data or through the conventional weather The required sunset time of each day can be obtained through scientific calculation; the second condition a condition is that during the period between the sunrise time of the current day and 30 minutes after the sunrise time of the next day, the maximum temperature difference ΔT _pmax and the maximum temperature difference of the reference plate The maximum temperature difference ΔT _smax on the surface of the cable structure is not greater than 5 degrees Celsius; the b condition of the second condition is that during the period between the sunrise of the day and 30 minutes after the sunrise of the next day, in the environment obtained by the previous measurement and calculation The maximum error ΔT _emax is not greater than the reference daily temperature difference ΔT _r , and the maximum temperature difference ΔT _pmax of the reference plate minus 2 degrees Celsius is not greater than ΔT _emax , and the maximum temperature difference ΔT _smax on the surface of the cable structure is not greater than ΔT _pmax ; it only needs to satisfy the second item a One of the condition and b condition is said to meet the second condition; the third condition is that at the moment when the steady-state temperature data of the cable structure is obtained, the absolute value of the temperature change rate of the environment where the cable structure is located with respect to time is not greater than each 0.1 degrees Celsius per hour; the fourth condition is that at the moment when the steady-state temperature data of the cable structure is obtained, the absolute value of the temperature change rate of each cable structure surface point in the R cable structure surface points with respect to time is not greater than 0.1 degrees Celsius per hour The fifth condition is that at the moment when the steady-state temperature data of the cable structure is obtained, the measured data of the cable structure surface temperature of each cable structure surface point in the R cable structure surface points is from the sunrise time of the day to the day after the sunrise time of the next day The minimum value between 30 minutes; the sixth condition is that at the moment when the steady-state temperature data of the cable structure is obtained, the "maximum temperature difference in the thickness direction of the cable structure" ΔT _tmax is not greater than 1 degree Celsius; this method utilizes the above six conditions, and the following Any one of the three kinds of time is called "mathematical time for obtaining the steady-state temperature data of the cable structure". Item 1 to item 5 conditions, the second type of time is the time that only meets the sixth condition in the above "conditions related to the time to determine the time to obtain the steady-state temperature data of the cable structure", and the third type of time is when the above-mentioned conditions are met at the same time The moment of the first item to the sixth condition in "Conditions related to the moment of determining the time to obtain the steady-state temperature data of the cable structure"; For one hour, the moment of obtaining the steady-state temperature data of the cable structure is the mathematical moment of obtaining the steady-state temperature data of the cable structure; Take the method closest to the mathematical moment of obtaining the steady-state temperature data of the cable structure The moment when the data is actually recorded is the moment when the steady-state temperature data of the cable structure is obtained; this method will use the amount measured and recorded at the moment when the steady-state temperature data of the cable structure is obtained to perform cable structure-related health monitoring analysis; this method approximately considers that the obtained cable structure The temperature field of the cable structure at the moment of the steady-state temperature data is in a steady state, that is, the temperature of the cable structure at this moment does not change with time, and this moment is the "moment of obtaining the steady-state temperature data of the cable structure" of this method; Thermal characteristics, using the "measured surface temperature data of R cable structures" and "measured data of temperature along the thickness of HBE cable structures" at the time when the steady-state temperature data of cable structures are obtained, using the heat transfer calculation model of cable structures, through conventional The thermal calculation obtains the temperature distribution of the cable structure at the moment when the steady-state temperature data of the cable structure is obtained. At this time, the temperature field of the cable structure is calculated according to the steady state. The temperature distribution data includes the calculated temperature of R cable structure surface points on the cable structure, and the calculated temperature of the R cable structure surface points is called the R cable structure steady-state surface temperature calculation data, and also includes the HBE selected in front of the cable structure. The calculation temperature of "points for measuring the temperature distribution data of the cable structure along the thickness", the calculation temperature of HBE "points for measuring the temperature distribution data of the cable structure along the thickness" is called "HBE temperature calculation data of the cable structure along the thickness", when When the measured data of the surface temperature of R cable structures is equal to the calculated data of the steady-state surface temperature of R cable structures, and the "measured data of the temperature along the thickness of the HBE cable structures" is correspondingly equal to the "calculated data of the temperature along the thickness of the HBE cable structures" , the calculated temperature distribution data of the cable structure at the moment when the cable structure steady-state temperature data is obtained is called "cable structure steady-state temperature data" in this method, and the "R cable structure surface temperature measured data" at this time is called is the "measured data of the steady-state surface temperature of R cable structures", and the "measured data of the temperature of the HBE cable structures along the thickness" is called "the measured data of the steady-state temperature of the HBE cable structures along the thickness"; cable structure surface points", the number and distribution of "R cable structure surface points" must meet three conditions. The first condition is that when the cable structure temperature field is in a steady state, when the temperature of any point on the cable structure surface When it is obtained by the linear interpolation of the measured temperature of the point adjacent to the arbitrary point on the surface of the cable structure among the "R cable structure surface points", the temperature of the arbitrary point on the surface of the cable structure obtained by linear interpolation is the same as the temperature of the arbitrary point on the surface of the cable structure The error of the actual temperature at any point is not greater than 5%; the surface of the cable structure includes the surface of the supporting cable; the second condition is that the number of points at the same altitude in the "R cable structure surface points" is not less than 4, and "R The points at the same altitude in "Cable Structure Surface Points" are evenly distributed along the cable structure surface; the absolute value of the difference in altitude between all pairwise adjacent cable structure surface points along the altitude of "R Cable Structure Surface Points" The maximum value of Δh is not greater than 0.2°C divided by ΔT _h . For the convenience of description, the unit of ΔT _h is ℃/m. For the convenience of description, the unit of Δh is m; "R The definition of two adjacent cable structure surface points along the altitude of the cable structure surface point means that when only the altitude is considered, there is no cable structure surface point in the "R cable structure surface points", and the cable structure surface point The altitude value of the cable structure is between the altitude values of two adjacent cable structure surface points; the third condition is to query or calculate according to meteorological routines to obtain the sunshine law of the cable structure location and the altitude interval, and then according to the cable structure Geometric features and azimuth data, find the positions of those surface points on the cable structure that receive the most sunshine time throughout the year, at least one cable structure surface point in the "R cable structure surface points" is the annual sunshine time on the cable structure one of those surface points that is most adequate;

c. According to the "temperature measurement and calculation method of the cable structure of this method", the steady-state temperature data of the cable structure in the initial state is directly measured and calculated, and the steady-state temperature data of the cable structure in the initial state is called the initial steady-state temperature data of the cable structure. It is recorded as "initial cable structure steady-state temperature data vector T _o "; the physical and mechanical performance parameters of various materials used in the cable structure that vary with temperature are obtained from actual measurement or information; the initial cable structure steady-state temperature data vector is obtained from the actual measurement At the same moment T _o , the initial cable forces of all supporting cables are directly measured and calculated to form the initial cable force vector F _o ; according to the data including cable structure design data and completed data, all supporting cables are in the free state, that is, the cable force is The length at 0, the cross-sectional area in the free state and the weight per unit length in the free state, as well as the temperature of all supporting cables when these three data are obtained, on this basis, the temperature-dependent Physical performance parameters and mechanical performance parameters, according to conventional physical calculations, the lengths of all supporting cables when the cable force is 0 and the lengths of all supporting cables when the cable force is 0 under the condition of the initial cable structure steady-state temperature data vector T _o The cross-sectional area and the weight per unit length of all supporting cables when the cable force is 0 form the initial free length vector of the supporting cables, the initial free cross-sectional area vector and the weight vector of the initial free unit length, and the initial free length vector of the supporting cables , the initial free cross-sectional area vector and the initial free unit length weight vector have the same numbering rules as the elements of the initial cable force vector _{F o} ; At the same moment of the state temperature data vector T _o , the measured data of the initial cable structure are directly measured and calculated, and the measured data of the initial cable structure include the concentrated load measurement data of the cable structure, the distributed load measurement data of the cable structure, and the body load measurement data of the cable structure data, initial values of all monitored quantities, initial cable force data of all supporting cables, initial cable structure modal data, initial cable structure strain data, initial cable structure geometry data, initial cable structure support generalized coordinate data, initial cable structure The measured data including the angle data and the initial cable structure space coordinate data, the generalized coordinate data of the initial cable structure support include the space coordinate data of the initial cable structure support and the initial cable structure support angular coordinate data, after obtaining the measured data of the initial cable structure At the same time, the data that can express the health state of the support cable including the non-destructive testing data of the support cable are obtained through measurement and calculation. At this time, the data that can express the health state of the support cable is called the initial health state data of the support cable; all monitored The initial value of the quantity constitutes the initial value vector C _o of the monitored quantity, and the numbering rule of the initial value vector C _o of the monitored quantity is the same as that of the M monitored quantities; it is established by using the initial health state data of the supporting cable and the load measurement data of the cable structure The initial damage vector d _o of the evaluated object, the vector d _o represents the initial health state of the evaluated object of the cable structure represented by the initial mechanical calculation benchmark model A _o ; The number of elements of the damage vector d _o is equal to N, and the elements of d _o have a one-to-one correspondence with the evaluated object. The numbering rule of the elements of the vector d _o is the same as that of the evaluated object; if a certain element of d _o corresponds to The object to be evaluated is a supporting cable in the cable system, then the value of this element of d _o represents the initial damage degree of the corresponding supporting cable, if the value of this element is 0, it means that the supporting cable corresponding to this element is intact , without damage, if its value is 100%, it means that the supporting cable corresponding to this element has completely lost its bearing capacity; if its value is between 0 and 100%, it means that the supporting cable has lost its corresponding proportion of bearing capacity capacity; if a certain element of d _o corresponds to a certain load, the value of this element of d _o is taken as 0 in this method, which means that the initial value of the change of this load is 0; if there is no non-destructive testing of supporting cables data and other data that can express the health state of the supporting cable, or when the initial state of the structure can be considered as a state of no damage and no relaxation, the value of each element related to the supporting cable in the vector d _o is set to 0; the generalized coordinates of the initial cable structure support The data constitute the generalized coordinate vector U _o of the initial cable structure support;

d. According to the design drawing of the cable structure, the as-built drawing and the actual measurement data of the initial cable structure, the initial health status data of the supporting cable, the measurement data of the concentrated load of the cable structure, the measurement data of the distributed load of the cable structure, the measurement data of the body load of the cable structure, and the data of the cable structure. The physical and mechanical performance parameters of various materials used as a function of temperature, the initial cable structure support generalized coordinate vector U _o , the initial cable structure steady-state temperature data vector T _o and all the cable structure data obtained in the previous steps, to establish the calculation The initial mechanical calculation benchmark model A _o of the cable structure is entered into the "steady-state temperature data of the cable structure". The calculated data of the cable structure based on A _o must be very close to the measured data, and the difference between them shall not be greater than 5%; corresponding to A _o The "cable structure steady-state temperature data" is the " _initial cable structure steady-state temperature data vector T _o "; the health state of the evaluated object corresponding to A _o is represented by the initial damage vector d _o of the evaluated object; The initial value of the monitored quantity is represented by the initial value vector C _o of the monitored quantity; for the first time, the current initial mechanical calculation benchmark model A ^t _o of the cable structure included in the "steady-state temperature data of the cable structure" is established, and the current initial value of the monitored quantity Numerical vector C ^t _o and “current initial cable structure steady-state temperature data vector T ^t _o ”; when the current initial mechanical calculation benchmark model A ^t _o of the cable structure and the current initial numerical vector C ^t _o of the monitored quantity are established for the first time, The current initial mechanical calculation benchmark model A ^t _o of the cable structure is equal to the initial mechanical calculation benchmark model A _o of the cable structure, and the current initial numerical vector C ^t _o of the monitored quantity is equal to the initial numerical vector C _o of the monitored quantity; A ^t _o corresponds to The "steady-state temperature data of the cable structure" is called "the current initial steady-state temperature data of the cable structure", which is recorded as "the vector T ^t _o of the current initial steady-state temperature data of the cable structure", and the current initial mechanical calculation of the cable structure is established for the first time When the benchmark model A ^t _o , T ^t _o is equal to T _o ; the generalized coordinate data of the cable structure support corresponding to the current initial mechanical calculation benchmark model A ^t _o of the cable structure constitutes the current initial cable structure support generalized coordinate vector U ^t _o , when the current initial mechanical calculation benchmark model A ^t _o of the cable structure is established for the first time, U ^t _o is equal to U _o ; the initial health status of the evaluated object of A ^t _o is the same as that of the evaluated object of A _o , It is also represented by the initial damage vector d _o of the evaluated object, and the initial health state of the evaluated object of A ^t _o is always represented by the initial damage vector d _o of the evaluated object in the subsequent cycle; T _o , U _o and d _o are The parameters of A _o , the initial values of all the monitored quantities obtained from the mechanical calculation results of A _o are the same as the initial values of all the monitored quantities represented by C _o , so it can also be said that C _o is composed of the mechanical calculation results of A _o ; T ^t _o , U ^t _o and d _o are parameters of A ^t _o , and C ^t _o is composed of mechanical calculation results of A ^t _o ;

e. From here, enter the cycle from step e to step n; during the service process of the structure, continuously measure and calculate according to the "temperature measurement and calculation method of the cable structure of this method" to obtain the current value of the "steady-state temperature data of the cable structure" data, the current data of "cable structure steady-state temperature data" is called "current cable structure steady-state temperature data", recorded as "current cable structure steady-state temperature data vector T ^t ", the definition of vector T ^t is the same as that of vector T _o are defined in the same way; at the same moment when the current steady-state temperature data vector T ^t of the cable structure is obtained from the actual measurement, the current data of the generalized coordinates of the cable structure supports are obtained from the actual measurement, and the current data of all the generalized coordinates of the cable structure supports form the generalized The coordinate vector U ^t , the definition of the vector U ^t is the same as the definition of the vector U _o ; when the current cable structure steady-state temperature data vector T ^t is obtained from the actual measurement, the newly added M ₂ sensing cables are non-destructively tested. Identify the damaged or slack sensory cords, and remove the corresponding sensory cords that are identified as damaged or slack from the vectors numbered according to the monitored quantity numbering rules that appear before the method according to the numbering rules of the monitored quantities. The elements of the vectors and matrices that appear after this method no longer appear corresponding to the identified damaged or slack sensory cords. When referring to the sensory cords after this method, the identified elements are no longer included here. Damaged or slack sensor cables, the cable force of the sensor cables identified as damage or slack here will no longer be included when referring to the monitored quantity after this method; If the sensing cable is loose, reduce M ₂ and M by the same amount; at the same moment when the steady-state temperature data vector T ^t of the current cable structure is measured, the measured cable force data of all M ₁ supporting cables in the cable structure , all these cable force data form the current cable force vector F, and the elements of the vector F have the same numbering rules as the elements of the vector F _o ; at the same moment when the current steady-state temperature data vector T ^t of the cable structure is obtained from the actual measurement, all M _The spatial coordinates of the two supporting end points of a supporting cable, the difference between the spatial coordinates of the two supporting end points in the horizontal direction is the horizontal distance between the two supporting end points, and the horizontal distance data of the two supporting end points of all the supporting cables constitute the current supporting cable two The horizontal distance vector of the support end points, the numbering rule of the elements of the horizontal distance vector between the two support end points of the current support cable is the same as the numbering rule of the elements of the initial cable force vector F _o ;

f. According to the current cable structure measured support generalized coordinate vector U ^t and the current cable structure steady-state temperature data vector T ^t , follow steps f1 to f3 to update the current initial mechanical calculation benchmark model A ^t _o and the current initial cable structure support generalized coordinates Vector U ^t _o , the current initial value vector C ^t _o of the monitored quantity and the current initial cable structure steady-state temperature data vector T ^t _o ;

f1. Compare U ^t with U ^t _o , T ^t with T ^t _o respectively, if U ^t is equal to U ^t _o and T ^t is equal to T ^t _o , then A ^t _o , U ^t _o , C ^t _o and T ^t _o remain Otherwise, A ^t _o , U ^t _o and T ^t _o need to be updated according to the following steps;

f2. Calculate the difference between U ^t and U _o . The difference between U ^t and U _o is the generalized displacement of the cable structure support relative to the initial position. The generalized displacement vector V of the support is used to represent the generalized displacement of the support. V is equal to U ^t minus Remove U _o , there is a one-to-one correspondence between the elements in the generalized displacement vector V of the support and the generalized displacement components of the support, and the value of an element in the generalized displacement vector V of the support corresponds to the generalized value of a specified direction of a specified support Displacement; calculate the difference between T ^t and T _o , the difference between T ^t and T _o is the change of the current cable structure steady-state temperature data with respect to the initial cable structure steady-state temperature data, the difference between T ^t and T _o uses the steady-state temperature change vector S means that S is equal to T ^t minus T _o , and S means the change of the steady-state temperature data of the cable structure;

f3. First apply the support generalized displacement constraint to the cable structure support in A _o , the value of the support generalized displacement constraint is taken from the value of the corresponding element in the support generalized displacement vector V, and then apply the support to the cable structure in A _o The temperature change, the value of the applied temperature change is taken from the steady-state temperature change vector S, the generalized displacement constraint of the support is applied to the support of the cable structure in A _o and the updated current is obtained after the temperature change is applied to the cable structure in A _o The initial mechanical calculation benchmark model A ^t _o , when A ^t _o is updated, the values of all elements of U ^t _o are also replaced by the corresponding values of all elements of U ^t , that is, U ^t _o is updated, and the values of all elements of T ^t _o are also replaced by the values of T ^t All element values are replaced accordingly, that is, T ^t _o is updated, so that T ^t _o and U ^t _o corresponding to ^A t o are obtained correctly; the method of updating C ^t _o is: after updating A ^t _{o ,} through mechanics The current specific values of all monitored quantities in A ^t _o are calculated, and these specific values form C ^t _o ; the initial health state of the supporting cable of A ^t _o is always represented by the initial damage vector d _o of the evaluated object;

g. Carry out several mechanical calculations according to steps g1 to g4 on the basis of the current initial mechanical calculation benchmark model A ^t _o , and obtain the numerical change matrix ΔC of the monitored quantity of cable structure unit damage and the unit change vector D _u of the evaluated object through calculation;

g1. The value change matrix ΔC of the monitored quantity of cable structure unit damage is constantly updated, that is, the current initial mechanical calculation benchmark model A ^t _o , the current initial cable structure support generalized coordinate vector U ^t _o , and the current initial value of the monitored quantity After the vector C ^t _o and the current initial cable structure steady-state temperature data vector T ^t _o , the cable structure unit damage value change matrix ΔC and the unit change vector D _u of the evaluated object must be updated;

g2. Carry out several mechanical calculations on the basis of the current initial mechanical calculation benchmark model A ^t _o of the cable structure. The number of calculations is numerically equal to the number N of all evaluated objects. There are N evaluation objects and there are N calculations; The numbering rules of the evaluation objects are calculated sequentially; each calculation assumes that there is only one evaluated object, and the unit damage or load unit change is added on the basis of the original damage or load. Specifically, if the evaluated object is a cable system If the supporting cable is rooted, then it is assumed that the supporting cable will add _unit damage on the basis of the existing damage of the supporting cable represented by the vector d _o . If the object to be evaluated is a load, it is assumed that the Add the change of load unit on the basis of the existing change of load, and use D _uk to record the increased unit damage or load unit change, where k represents the number of the evaluated object that increases the unit damage or load unit change, and D _uk is the An element of the unit change vector D _u of the evaluated object, the numbering rule of the elements of the unit change vector D _u of the evaluated object is the same as that of the elements of the vector d _o ; the evaluated object of the unit damage or load unit change is added in each calculation Different from the evaluated objects that increase unit damage or load unit changes in other calculations, each calculation uses the mechanical method to calculate the current calculation values of all monitored quantities of the cable structure, and the current calculation values of all monitored quantities obtained from each calculation Values form a monitored quantity to calculate the current vector, and the element numbering rule of the monitored quantity to calculate the current vector is the same as the element numbering rule of the initial value vector C _o of the monitored quantity;

g3. Calculate the current vector of the monitored quantity obtained by each calculation and subtract the current initial value vector C ^t _o of the monitored quantity to obtain a vector, and then divide each element of the vector by the unit damage or load assumed for this calculation Unit change value, get a monitored quantity unit change vector, if there are N evaluated objects, there will be N monitored quantity unit change vectors;

g4. According to the numbering rules of the N evaluated objects, the change vectors of the N monitored quantity units are sequentially formed into a numerical change matrix ΔC of the monitored quantity damage of the cable structure unit with N columns; the numerical change matrix of the monitored quantity damage of the cable structural unit Each column of ΔC corresponds to a monitored quantity unit change vector; each row of the cable structure unit damage monitored quantity value change matrix ΔC corresponds to the difference of the same monitored quantity when different evaluated objects increase unit damage or load unit changes The unit change range of the cable structure unit damage value change matrix ΔC is the same as the numbering rule of the elements of the vector d _o , and the row numbering rule of the cable structure unit damage value change matrix ΔC is the same as that of M The numbering rules of the monitored quantities are the same;

h. Obtaining ^the current measured values of all monitored quantities of the cable structure at the same moment when the current cable structure steady-state temperature data vector T ^t is obtained through actual measurement, Composing the current numerical vector C of the monitored quantity; the current numerical vector C of the monitored quantity and the current initial numerical vector C ^t _o of the monitored quantity are defined in the same way as the initial numerical vector C _o of the monitored quantity, and the elements of the same number of the three vectors represent Specific values of the same monitored quantity at different times;

i. Define the current nominal damage vector d of the evaluated object, the number of elements of the current nominal damage vector d of the evaluated object is equal to the number of evaluated objects, and the elements of the current nominal damage vector d of the evaluated object and the evaluated object are one by one Corresponding relationship, the element value of the current nominal damage vector d of the evaluated object represents the nominal damage degree or nominal load change of the corresponding evaluated object; the numbering rule of the elements of the vector d is the same as that of the elements of the vector d _o ;

j. According to the approximate linearity existing between the current numerical vector C of the monitored quantity and the current initial numerical vector C ^t _o of the monitored quantity, the numerical change matrix ΔC of the monitored quantity damaged by the cable structure unit, and the current nominal damage vector d of the evaluated object to be obtained The approximate linear relationship can be expressed as formula 1. In formula 1, other quantities except d are known, and the current nominal damage vector d of the evaluated object can be calculated by solving formula 1;

$C=C_o^t+\mathrm{\ΔC}\&Center\; Dot;d$ Formula 1

k. Define the current actual damage vector d ^a of the evaluated object, the number of elements of the current actual damage vector d ^a of the evaluated object is equal to the number of evaluated objects, and the distance between the elements of the current actual damage vector d ^a of the evaluated object and the evaluated object It is a one-to-one correspondence relationship, the element value of the current actual damage vector d ^a of the evaluated object represents the actual damage degree or actual load change of the corresponding evaluated object; the numbering rule of the elements of the vector d ^a is the same as the numbering rule of the elements of the vector d _o same;

1. The kth element d a k of the current actual damage vector d ^a of the evaluated object expressed by formula 2 is the same as the kth element ^d _ok of the _initial damage vector d _o of the evaluated object and the current nominal damage vector d of the evaluated object The relationship between the kth element d _k is calculated to obtain all the elements of the current actual damage vector d ^a of the evaluated object;

In formula 2, k=1,2,3,...,N, d ^a _k represents the current actual health status of the kth evaluated object, and when d ^a _k is 0, it means that the kth evaluated object has no health problems, When the value of d ^a _k is not 0, it means that the kth evaluated object is an evaluated object with health problems. If the evaluated object is a supporting cable in the cable system, then d ^a _k represents the severity of its current health problem The supporting cables with health problems may be slack cables or damaged cables, and the d ^a _k value reflects the degree of slack or damage of the supporting cables; the damaged cables can be identified from these supporting cables with health problems , the rest is the slack cable, the value of the elements corresponding to the slack cable in the current actual damage vector d ^a of the evaluated object expresses the current actual equivalent damage degree mechanically equivalent to the relaxation degree of the slack cable; if the evaluated object is a load, then d ^a _k represents the actual variation of the load;

m. Utilize the slack cables identified in the first step under the condition of the current steady-state temperature data vector T ^t of the cable structure and the mechanics of these slack cables expressed by the current actual damage vector d ^a of the evaluated object and their degree of relaxation, etc. The effective current actual equivalent damage degree, using the current cable force vector F and the horizontal distance vector between the two supporting ends of the current cable structure under the condition of the current cable structure steady-state temperature data vector T ^t obtained in step e, using the The initial free length vector of the supporting cable, the initial free cross-sectional area vector, the initial free unit length weight vector, and the initial cable force vector F _o under the condition of the initial cable structure steady-state temperature data vector T _o obtained in the first step, using the current cable The current steady-state temperature data of the support cable represented by the structural steady-state temperature data vector T ^t is used to obtain the initial steady-state temperature data of the support cable represented by the initial cable structure steady-state temperature data vector T _o obtained in the cth step, and the c The temperature-dependent physical and mechanical performance parameters of various materials used in the cable structure obtained in the first step, taking into account the influence of temperature changes on the physical, mechanical and geometric parameters of the supporting cable, through the mechanical equivalent of the slack cable and the damaged cable To calculate the relaxation degree equivalent to the current actual equivalent damage degree of the slack cable, the mechanical equivalent conditions are: the initial free length, geometric characteristic parameters, density and The mechanical characteristic parameters of the material are the same; 2. After relaxation or damage, the cable force and the total length after deformation of the two equivalent slack cables and damaged cables are the same; when the above two mechanical equivalent conditions are met, such two supporting cables The mechanical functions in the cable structure are exactly the same, that is, if the damaged cable is replaced by an equivalent slack cable, the cable structure will not change, and vice versa; The degree of slack of the cables, the degree of slack is the change in the free length of the supporting cables, that is, the adjustment of the cable lengths of the supporting cables whose force needs to be adjusted is determined; in this way, the slack identification and damage identification of the supporting cables are realized; The required cable force is given by the corresponding elements of the current cable force vector F; in this method, damaged cables and slack cables are collectively referred to as support cables with health problems, referred to as problem cables. Therefore, this method is based on the current actual damage vector d of the evaluated object ^a. It can not only identify the problem cable, but also determine which loads have changed and the value of the change; so far, this method has realized the problem cable identification of the cable structure by eliminating the influence of the generalized displacement of the support, load change and structural temperature change , and at the same time realize the identification of the load variation which excludes the influence of the generalized displacement of the support, the structure temperature change and the health state change of the support cable;

n. Go back to step e and start the next cycle from step e to step n.

Beneficial effects: This method realizes two functions that the existing methods cannot have, namely: 1. When the cable structure undergoes a generalized displacement of the support, and when the load on the structure and the temperature of the structure (environment) change, the cable can be eliminated. The impact of generalized displacement of structural support, load change and structural temperature change on the identification results of cable structure health status, so as to accurately identify the structural health monitoring method of problem cables; 2. This method can simultaneously identify problem cables. The change of the load is identified, that is, the method can eliminate the influence of the generalized displacement of the support of the cable structure, the change of the structure temperature, and the change of the health state of the support cable, and realize the correct identification of the degree of load change.

Detailed ways

The method employs an algorithm that is used to identify problematic cables and load changes. During specific implementation, the following steps are one of various steps that may be taken.

Step 1: First identify the amount of possible varying loads that the cable structure will be subjected to. According to the characteristics of the loads borne by the cable structure, confirm "all possible changing loads", or regard all the loads as "all possible changing loads", and assume a total of JZW possible changing loads, this method passes Identify the change degree of these JZW "all possible changeable loads" to express the change amount of "all possible changeable loads".

Let the sum of the number of supporting cables of the cable structure and the number of JZW "all possible changing loads" be N. For the convenience of description, this method collectively refers to the evaluated support cables and "all possible changing loads" as "evaluated objects", and there are N evaluated objects in total. Consecutively number the evaluated objects, which will be used to generate vectors and matrices in subsequent steps.

Assuming that there are M ₁ supporting cables in the cable system, the structural cable force data includes the cable force of these M ₁ supporting cables, obviously M ₁ is smaller than the number N of the evaluated objects. It is impossible to solve the unknown state of N evaluated objects only by M ₁ cable force data of M ₁ supporting cables. On the basis of monitoring all M ₁ supporting cable forces, this method adds no less than (NM ₁ ) other monitored quantities.

The other monitored quantities increased by not less than (NM ₁ ) are still cable forces, described as follows:

Before the structural health detection system starts to work, M ₂ (M ₂ is not less than NM ₁ ) cables are artificially added to the cable structure, which are called sensing cables. The stiffness of the newly added M ₂ sensing cables is the same as that of the cable structure. Compared with the stiffness of any supporting cable, it should be much smaller, such as 20 times smaller, and the cable force of the newly added M ₂ sensing cables should be smaller, for example, the normal stress of its cross section should be less than its fatigue limit, these requirements can be Ensure that the newly added M ₂ sensing cables will not suffer from fatigue damage, the two ends of the newly added M ₂ sensing cables should be fully anchored to ensure that there will be no slack, and the newly added M ₂ sensing cables should be fully anchored. The anti-corrosion protection ensures that the newly added M ₂ sensing cables will not be damaged and slack, and the cable force of the newly added M ₂ sensing cables will be monitored during the structural health monitoring process.

It is also possible to increase the reliability of health monitoring by adding more sensing cables, for example, make M ₂ not less than twice NM ₁ , and only select the cable force data of intact sensing cables in the process of structural health monitoring ( It is called the actual monitored quantity that can be used, and its quantity is recorded as K, K must not be less than N) and the corresponding cable structure monitored quantity unit change matrix ΔC for health status assessment. Since M ₂ is not less than 2 times of NM ₁ , it can Ensure that the number of effective sensing cables that can actually be used plus M ₁ is not less than N. The cable force of the newly added M ₂ sensing cables will be monitored during the structural health monitoring process. The newly added M ₂ sensing cables should be installed on the structure, where personnel can easily reach, so that personnel can conduct non-destructive testing on it.

In this method, the newly added M ₂ sensing cables are used as part of the cable structure. When referring to the cable structure later, the cable structure includes the cable structure before adding M ₂ sensing cables and the newly added M ₂ The sense cable, that is to say, when the cable structure is mentioned later, refers to the cable structure including the newly added _M2 sensing cables. Therefore, when it is mentioned later that the "cable structure steady-state temperature data" is measured and calculated according to "the temperature measurement and calculation method of the cable structure of this method", the cable structure includes newly added _M2 sensing cables, and the obtained "cable structure The "structure steady-state temperature data" includes the steady-state temperature data of the newly added M ₂ sensing cables, and the method of obtaining the steady-state temperature data of the newly added M ₂ sensing cables is the same as that of the M ₁ supporting cables of the cable structure. The method of obtaining the steady-state temperature data will not be explained one by one in the following text; the method of measuring the cable force of the newly added M ₂ sensing cables is the same as the method of measuring the cable force of the M ₁ supporting cables of the cable structure, It will not be explained one by one in the following text; when any measurement is performed on the supporting cables of the cable structure, the same measurement will be carried out on the newly added M ₂ sensing cables, which will not be explained one by one in the following text; the newly added M ₂ In addition to the absence of damage and slack in the root sensing cables, the information volume of the newly added M ₂ cables is the same as that of the supporting cables of the cable structure, which will not be explained one by one in the following; the newly added M ₂ sensor cables The cable force of the cable is the addition of not less than (NM ₁ ) other monitored quantities. When establishing various mechanical models of the cable structure later, the newly added M ₂ sensing cables are treated as the M ₁ supporting cables of the cable structure. References to support cables include the newly added M ₂ cables.

Based on the above-mentioned monitored quantities, the entire cable structure has M monitored quantities of M (M=M ₁ +M ₂ ) cables, and M must not be less than the number N of evaluated objects.

For convenience, in this method, "all monitored parameters of the cable structure" are referred to as "monitored quantities" for short. Number the M monitored quantities consecutively, and this number will be used to generate vectors and matrices in subsequent steps. This method uses the variable j to represent this number, j=1,2,3,...,M.

Determine the "temperature measurement and calculation method of the cable structure of this method" according to the steps specified in the technical plan.

The second step: establish the initial mechanical calculation benchmark model A _o .

When the cable structure is completed, or before the health monitoring system is established, the "cable structure steady-state temperature data" is measured and calculated according to the "temperature measurement and calculation method of the cable structure of this method" (it can be measured by conventional temperature measurement methods, such as using Thermal resistance measurement), the "cable structure steady-state temperature data" at this time is represented by vector T _o , which is called the initial cable structure steady-state temperature data vector T _o . At the same time when T _o is obtained from the actual measurement, that is, at the same moment when the steady-state temperature data vector of the initial cable structure is obtained, the initial values of all monitored quantities of the cable structure are directly measured and calculated by conventional methods, and the initial values of the monitored quantities are formed Vector C _o .

In this method, the following method can be used to measure and calculate a certain measured quantity and monitored quantity (such as a cable structure) at the same moment when the steady-state temperature data vector of a certain (such as initial or current) cable structure is obtained. All monitored quantities of the structure) data: while measuring and recording the temperature (including the air temperature of the environment where the cable structure is located, the temperature of the sunny side of the reference plate and the surface temperature of the cable structure), for example, measuring and recording the temperature every 10 minutes, then At the same time, the data of a certain measured quantity and monitored quantity (for example, all monitored quantities of the cable structure) are also measured and recorded every 10 minutes. Once the time to obtain the steady-state temperature data of the cable structure is determined, the data of a certain measured quantity and monitored quantity (for example, all monitored quantities of the cable structure) at the same time as the time when the steady-state temperature data of the cable structure is obtained is called At the same moment when the steady-state temperature data of the cable structure is obtained, the data of a certain measured quantity and a certain monitored quantity obtained by a certain method are measured by a certain method.

The physical parameters (such as thermal expansion coefficient) and mechanical performance parameters (such as elastic modulus and Poisson's ratio) of various materials used in the cable structure that vary with temperature are obtained using conventional methods (research information or actual measurement).

At the same moment when the steady-state temperature data vector T _o of the initial cable structure is obtained from the actual measurement, the initial cable forces of all the supporting cables are directly measured and calculated to form the initial cable force vector F _o ; The free state is the length when the cable force is 0, the cross-sectional area in the free state and the weight per unit length in the free state, and the temperature of all supporting cables when these three data are obtained. According to the physical performance parameters and mechanical performance parameters of cables that change with temperature, according to conventional physical calculations, the length and cable force of all supporting cables when the cable force is 0 under the condition of the initial cable structure steady-state temperature data vector T _o are: The cross-sectional area of all supporting cables at 0 and the weight per unit length of all supporting cables when the cable force is 0 constitute the initial free length vector l _o , the initial free cross-sectional area vector A _o and the initial free unit length of the supporting cables in sequence The numbering rules of the weight vector ω _o , the initial free length vector l _o of the supporting cable, the initial free cross-sectional area vector A _o and the initial free unit length weight vector ω _o are the same as the numbering rules of the elements of the initial cable force vector F _o same.

According to the steps specified in the technical plan, when the initial cable structure steady-state temperature data vector T _o is obtained through actual measurement and calculation, that is, at the same moment when the cable structure steady-state temperature data is obtained, the actual measurement and calculation of the cable structure is obtained through actual measurement and calculation using conventional methods data. Utilize the design drawing, as-built drawing of the cable structure, the measured data of the initial cable structure, the non-destructive testing data of the supporting cable, the physical and mechanical performance parameters of various materials used in the cable structure as a function of temperature, and the generalized coordinates of the initial cable structure support The vector U _o and the initial cable structure steady-state temperature data vector T _o are incorporated into the "cable structure steady-state temperature data" using mechanical methods (such as finite element method) to establish the initial mechanical calculation benchmark model A _o . T _o , U _o and d _o are parameters of A _o , and C _o is composed of mechanical calculation results of A _o .

Step 3: Establish the current initial mechanical calculation benchmark model A ^t _o , the current initial value vector C ^t _o of the monitored quantity, and the "current initial cable structure steady-state temperature data vector T ^t _o " for the first time. The specific method is: at the initial Time, that is, when the current initial mechanical calculation benchmark model A ^t _o and the current initial value vector C ^t _o of the monitored quantity are established for the first time, A ^t _o is equal to A _o , C ^t _o is equal to C _o , and A ^t _o corresponds to "Cable structure steady-state temperature data" is recorded as "the current initial cable structure steady-state temperature data vector T ^t _o ", at the initial moment (that is, when A ^t _o is established for the first time), T ^t _o is equal to T _o , and the vector T ^t _o is defined in the same way as vector T _o . The generalized coordinate data of the cable structure support corresponding to the current initial mechanical calculation benchmark model A ^t _o of the cable structure constitutes the current initial cable structure support generalized coordinate vector U ^t _o ; the current initial mechanical calculation benchmark model A of the cable structure is established for the first time When ^t _o , U ^t _o is equal to U _o . The health state of the evaluation object of A ^t _o is the same as the health state of the evaluation object of A _o (represented by the initial damage vector d _o of the evaluation object), and the health state of the evaluation object of A ^t _o is always initialized with the evaluation object The damage vector d _o represents. T ^t _o , U ^t _o and d _o are parameters of A ^t _o , and C ^t _o is composed of mechanical calculation results of A ^t _o .

Step 4: During the service process of the cable structure, the current data of the "steady-state temperature data of the cable structure" (called "current steady-state temperature data of the cable structure") are continuously measured and calculated according to "the temperature measurement and calculation method of the cable structure of this method". Vector T ^t ”, the vector T ^t is defined in the same way as the vector T _o ). At the same time when the current steady-state temperature data vector T ^t of the cable structure is obtained by actual measurement, that is, at the same moment when the current steady-state temperature data vector T ^t of the cable structure is obtained, the current measured values of all monitored quantities of the cable structure are obtained by actual measurement, Form "the current value vector C of the monitored quantity".

While the steady-state temperature data vector T ^t of the current cable structure is obtained from the actual measurement, the current data of the generalized coordinates of the support of the cable structure are also obtained from the actual measurement, and all the data form the generalized coordinate vector U ^t of the measured support of the current cable structure.

At the same moment when the steady-state temperature data vector T ^t of the current cable structure is measured, the cable force data of all M ₁ supporting cables in the cable structure are measured. All these cable force data form the current cable force vector F, and the elements of the vector F are equal to The numbering rules of the elements of the vector F _o are the same; at the same moment when the current cable structure steady-state temperature data vector T ^t is obtained from the actual measurement, the spatial coordinates of the two support end points of all M ₁ support cables are obtained through actual measurement and calculation, and the two support end points The difference of the spatial coordinates in the horizontal direction is the horizontal distance between the two supporting endpoints. The horizontal distance data of the two supporting endpoints of all M ₁ supporting cables constitute the horizontal distance vector l ^t _x between the two supporting endpoints of the current supporting cable, and the two supporting endpoints of the current supporting cable The numbering rules of the elements of the horizontal distance vector l ^t _x are the same as the numbering rules of the elements of the initial cable force vector F _o .

Step 5: According to the current cable structure measured support generalized coordinate vector U ^t and the current cable structure steady-state temperature data vector T ^t , if necessary, update the current initial mechanical calculation benchmark model A ^t _o and the current initial cable structure support generalized coordinates Vector U ^t _o , the current initial value vector C ^t _o of the monitored quantity, and the current initial cable structure steady-state temperature data vector T ^t _o . After obtaining the generalized coordinate vector U ^t of the measured support of the current cable structure and the steady-state temperature data vector T ^t of the current cable structure in the fourth step, compare U ^t with U ^t _o , T ^t and T ^t _o , if U ^t is equal to U ^t _o and T ^t is equal to T ^t _o , then there is no need to update A ^t _o , U ^t _o and T ^t _o , otherwise A ^t _o , U ^t _o and T ^t _o need to be updated. The update method depends on the technology The program specifies the steps to be carried out.

Step 6: According to the steps _stipulated in the technical plan, several mechanical calculations are performed on the basis of the current initial mechanical calculation benchmark model A ^to , and the numerical change matrix ΔC of the monitored quantity of cable structure unit damage and the unit change vector of the evaluated object are obtained through calculation D _u . Specifically, if the evaluated object is a supporting cable in the cable system, then it is assumed that the supporting cable has a unit damage on the basis of the existing damage of the supporting cable represented by the vector d _o (for example, take 5%, 10 %, 20% or 30% damage as unit damage), if the object to be evaluated is a load, it is assumed that the load will increase the load unit change on the basis of the existing change of the load represented by the vector d _o (if the The load is a distributed load, and the distributed load is a linear distributed load, and the load unit change can be 1kN/m, 2kN/m, 3kN/m or 1kNm/m, 2kNm/m, 3kNm/m, etc.; if the load It is a distributed load, and the distributed load is a surface distributed load, and the load unit can be changed in units of 1MPa, 2MPa, 3MPa or 1kNm/m ² , 2kNm/m ² , 3kNm/m ² ; if the load is a concentrated load , and the concentrated load is a force couple, the load unit can be changed in units of 1kNm, 2kNm, 3kNm, etc. unit change; if the load is body load, the load unit change can take 1kN/m ³ , 2kN/m ³ , 3kN/m ³ etc. as the unit change).

Step 7: Establish linear relationship error vector e and vector g. Using the previous data (the current initial value vector C ^t _o of the monitored quantity, and the numerical change matrix of the monitored quantity per unit damage ΔC), while performing each calculation in the sixth step, that is, in each calculation, it is assumed that there is only one The increased unit damage or load unit change D _uk of the assessed object, the assessed object with increased unit damage or load unit change in each calculation is different from the assessed object with increased unit damage or load unit change in other calculations, each calculation Both use mechanical methods (such as finite element method) to calculate the current values of all monitored quantities in the cable structure, and each calculation forms a monitored quantity. At the same time as calculating the current vector C, each calculation forms a damage vector d. This step appears The damage vector d of the damage vector d is only used in this step. Among all the elements of the damage vector d, the value of only one element is D _uk , and the value of other elements is 0. The numbering rule of the elements of the damage vector d is the same as the numbering rule of the elements of the vector d _o The same; put C, C ^t _o , ΔC, _Du , d into formula (1) to get a linear relationship error vector e, each calculation will get a linear relationship error vector e; if there are N evaluated objects, there will be N Once calculated, there are N linear relationship error vectors e, and the N linear relationship error vectors e are added to obtain a vector, and the new vector obtained after dividing each element of this vector by N is the final linear relationship error vector e. The vector g is equal to the final error vector e.

$\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; abs</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula (1), abs() is an absolute value function, and the absolute value is taken for each element of the vector obtained in the brackets.

Step 8: Install the hardware part of the cable structure health monitoring system. The hardware part includes at least: monitored quantity monitoring system (such as cable force measurement system, signal conditioner, etc.), cable structure support generalized coordinate monitoring system (including angle measurement sensor, signal conditioner, etc.), cable structure temperature monitoring system ( Including temperature sensor, signal conditioner, etc.) and cable structure environmental temperature measurement system (including temperature sensor, signal conditioner, etc.), spatial coordinate monitoring system of the supporting end point of the supporting cable, signal (data) collector, computer and communication alarm equipment . Each monitored quantity, the generalized coordinates of each support of the cable structure, each temperature, the cable force of each supporting cable, and the spatial coordinates of the supporting end points of each supporting cable must be monitored by the monitoring system. The monitored signal is transmitted to the signal (data) collector; the signal is transmitted to the computer through the signal collector; the computer is responsible for running the health monitoring software of the evaluated object of the cable structure, including recording the signal transmitted by the signal collector; when monitoring When there is a change in the health status of the evaluated object, the computer controls the communication alarm device to alarm the monitoring personnel, the owner and (or) the designated personnel.

Step 9: Save the current initial value vector C ^t _o of the monitored quantity, the numerical change matrix ΔC of the monitored quantity per unit damage, and the unit change vector D _u of the evaluated object as data files on the hard disk of the computer running the health monitoring system software superior.

The tenth step: compiling and installing and running this method system software on the computer, this software will complete functions such as monitoring, recording, control, storage, calculation, notification, and alarm required by this method task (that is, all possible functions in this specific implementation method work done with a computer)

Step 11: According to the current numerical vector C of the monitored quantity, the current initial numerical vector C ^t _o of the monitored quantity, the numerical change matrix ΔC of the monitored quantity for unit damage, the unit change vector D _u of the evaluated object, and the current nominal damage of the evaluated object The approximate linear relationship (formula (2)) exists between the vector d (consisting of the current nominal damage of all cables), and the non-inferior solution of the current nominal damage vector d of the evaluated object is calculated according to the multi-objective optimization algorithm, that is, with a reasonable error , but the position of the damaged cable and the solution of the nominal damage degree can be determined more accurately from all the cables.

$\mathrm{<span\; class="notranslate">\; C</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

The current damage vector d can be obtained by solving Equation (2) using the Goal Attainment Method in the multi-objective optimization algorithm.

The number of elements of the current nominal damage vector d of the evaluated object is equal to the number of evaluated objects. There is a one-to-one correspondence between the elements of the current nominal damage vector d of the evaluated object and the evaluated object. The current nominal damage vector d of the evaluated object The element value represents the nominal damage degree or the nominal load change degree of the corresponding evaluated object; the numbering rule of the elements of the vector d is the same as that of the elements of the vector d _o .

Step 12: Define the current actual damage vector d ^a of the evaluated object, the number of elements of the current actual damage vector d ^a of the evaluated object is equal to the number of evaluated objects, the elements of the current actual damage vector d ^a of the evaluated object There is a one-to-one correspondence between the objects. The element value of the current actual damage vector d ^a of the evaluated object represents the actual damage degree or actual load change degree of the corresponding evaluated object; the numbering rules of the elements of the vector d ^a are the same as the elements of the vector d _o The numbering rules are the same. Use the k-th element d ^a _k of the current actual damage vector d ^a of the evaluated object, the k-th element d _ok of the initial damage vector d _o of the evaluated object, and the k-th element d _k of the current nominal damage vector d of the evaluated object The relationship among all the elements of the current actual damage vector d ^a of the evaluated object is calculated.

d ^a _k represents the current actual health status of the kth evaluated object. If the evaluated object is a supporting cable in the cable system, then d ^a _k represents its current actual damage. When d ^a _k is 0, it represents its corresponding There is no health problem in the supporting cables. When the value of d ^a _k is not 0, it means that the corresponding supporting cables have health problems. The supporting cables with health problems may be slack cables or damaged cables. The value reflects The degree of relaxation or damage; if the object to be evaluated is a load, then d ^a _k represents its change relative to the corresponding load borne by the structure when the initial mechanical calculation benchmark model A _o is established.

Step 13: Take out the M ₁ elements related to the support cable from the current actual damage vector d ^a of the evaluated object, and form the current actual damage vector d ^ca of the support cable, the numbering rule of the elements of the current actual damage vector d ^ca of the support cable The numbering rules are the same as the elements of the initial cable force vector F _o . The hth element of the current actual damage vector d ^ca of the supporting cable represents the current actual damage amount of the hth supporting cable in the cable structure, h=1,2,3,...,M ₁ ; the current actual damage vector d of the supporting cable The elements in ^ca whose value is not 0 correspond to the supporting cables with health problems, and the damaged cables are identified from these supporting cables with health problems by non-destructive testing methods, and the rest are slack cables, which are cables whose force needs to be adjusted , the values of the elements corresponding to the current actual damage vector d ^ca of the supporting cables for which the cable forces need to be adjusted (for example, one of the elements can be represented by d ^ca _h ) represent the damage degree mechanically equivalent to the relaxation degree of these supporting cables, which is given by This defines the slack cord. The value of the corresponding element of the damaged cable in the current actual damage vector d ^ca of the supporting cable indicates its damage degree. When the value of the corresponding element is 100%, it means that the supporting cable completely loses its bearing capacity, and when it is between 0 and 100%. Indicates that the supporting cable loses a corresponding proportion of its bearing capacity, so far the damaged cable and its damage degree have been identified.

Step 14: Taking into account the influence of temperature changes on the physical, mechanical and geometric parameters of the supporting cable, the slack equivalent to the current actual equivalent damage degree of the slack cable is calculated by mechanically equivalenting the slack cable to the damaged cable Specifically, the degree of relaxation of these cables (that is, the amount of cable length adjustment) can be obtained according to formula (3). This enables slack detection of the support cables. Damaged and slack cables are now fully identified.

${\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; ca</span>}}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; ca</span>}}}\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}}{<span\; class="notranslate">\; [</span>\frac{{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; xh</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}}{\mathrm{<span\; class="notranslate">\; 12</span>}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}}}<span\; class="notranslate">\; ]</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; oh</span>}}^{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In formula (3), E ^t _h is the elastic modulus of the hth supporting cable when the steady-state temperature data of the cable structure is represented by the current initial cable structure steady-state temperature data vector T ^t _o , A ^t _h is the elastic modulus of the cable structure When the steady-state temperature data of the current initial cable structure steady-state temperature data vector T ^t _o is represented, the cross-sectional area of the hth supporting cable, F _h is the steady-state temperature data of the cable structure, and the current initial cable structure steady-state temperature When the data vector T ^t _o represents the current cable force of the h-th supporting cable, d ^ca _h is the current actual damage degree of the h-th supporting cable, ω ^t _h is the steady-state temperature data of the cable structure with the current initial cable structure When the steady-state temperature data vector T ^t _o represents, the weight per unit length of the h-th supporting cable, l ^t _xh is when the steady-state temperature data of the cable structure is represented by the current initial cable structure steady-state temperature data vector T ^t _o , The horizontal distance between the two supporting endpoints of the h-th supporting cable, l ^t _xh is an element of the horizontal distance vector l t _x between the two supporting endpoints of the current supporting cable, and the element number of the horizontal distance vector ^{l t x} _between the two supporting endpoints of the current supporting cable The rules are the same as the numbering rules of the elements of the initial free length vector l _o , E ^t _h can be obtained from the investigation or actual measurement of the material property data of the h-th support cable, A ^t _h and ω ^t _h can be obtained according to the thermal expansion of the h-th support cable Coefficients, A _oh , ω _oh , F _h , T _o and T ^t _o are calculated by conventional physics and mechanics.

Step 15: The computer in the health monitoring system generates reports on the health status of the cable system automatically or by personnel operating the health monitoring system on a regular basis.

Step 16: Under the specified conditions, the computer in the health monitoring system automatically operates the communication alarm equipment to alarm the monitoring personnel, the owner and (or) the designated personnel.

Step 17: Go back to Step 4 and start the cycle from Step 4 to Step 17.

Claims (1)

1. Generalized displacement cable force monitoring problem cable load identification method, it is characterized in that described method comprises: a. For the convenience of description, this method collectively refers to the evaluated supporting cables and loads as the evaluated objects, and the sum of the number of evaluated supporting cables and the number of loads is N, that is, the number of evaluated objects is N; determine The numbering rule of the evaluated object. According to this rule, all the evaluated objects in the index structure will be numbered. This number will be used to generate vectors and matrices in the subsequent steps; this method uses the variable k to represent this number, k=1,2 ,3,...,N; Suppose there are M ₁ supporting cables in the cable system, the cable force data of the cable structure includes the cable force of these M ₁ supporting cables, obviously M ₁ is smaller than the number N of the evaluated objects; only through M ₁ It is impossible to solve the unknown state of N evaluated objects with M ₁ cable force data of supporting cables. This method artificially adds M ₂ cables to the cable structure on the basis of monitoring all M ₁ supporting cable forces. , called sensing cables, will monitor the cable forces of the newly added M ₂ sensing cables during the cable structure health monitoring; based on the above-mentioned monitored quantities, the entire cable structure has a total of M cable forces of M cables to be monitored , that is, there are M monitored quantities, where M is the sum of M ₁ and M ₂ ; M should be greater than the number N of objects to be evaluated; the stiffness of the newly added M ₂ sensing cables is the same as any supporting cable of the cable structure should be much smaller than the stiffness of the cable structure; the cable force of each sensor cable of the newly added M ₂ sensor cables should be much smaller than the cable force of any supporting cable of the cable structure, so that it can be guaranteed that even if the newly added The damage or relaxation of the M ₂ sensing cables has little effect on the stress, strain, and deformation of other components of the cable structure; the normal stress on the cross-section of the newly added M ₂ sensing cables should be less than its fatigue limit. It is required to ensure that the newly added M ₂ sensing cables will not suffer from fatigue damage; the two ends of the newly added M ₂ sensing cables should be fully anchored to ensure that there will be no slack; the newly added M ₂ sensing cables should be Get sufficient anti-corrosion protection to ensure that the newly added _M2 sensing cables will not be damaged or loosened; for convenience, in this method, "all monitored parameters of the cable structure" are referred to as "monitored quantities"; Continuously number the M monitored quantities, this method uses the variable j to represent this number, j=1,2,3,...,M, this number will be used to generate vectors and matrices in subsequent steps; in this method The newly added M ₂ sensing cables are part of the cable structure. When referring to the cable structure later, the cable structure includes the cable structure before adding the M ₂ sensing cables and the newly added M ₂ sensing cables. That is to say, when referring to the cable structure later on, it refers to the cable structure including the newly added M ₂ sensing cables; When the cable structure includes newly added M ₂ sensing cables, the obtained "cable structure steady-state temperature data" includes the newly added steady-state temperature data of M ₂ sensing cables, and the newly added The method for obtaining the steady-state temperature data of the M ₂ sensing cables is the same as the method for obtaining the steady-state temperature data of the M ₁ supporting cables in the cable structure, and will not be explained one by one in the following text; The method for measuring the cable force of the newly added M ₂ sensing cables is the same as the method for measuring the cable force of the M ₁ supporting cables of the cable structure, and will not be explained one by one in the following text; During the measurement, the same measurement is carried out on the newly added M ₂ sensing cables at the same time, which will not be explained one by one in the following; except that the newly added M ₂ sensing cables do not occur damage and relaxation, the newly added M The information requirements and acquisition methods of the _two sensing cables are the same as the information requirements and acquisition methods of the supporting cables of the cable structure, and will not be explained one by one in the following; when establishing various mechanical models of the cable structure in the following , treat the newly added M ₂ sensing cables as the supporting cables of the cable structure; in the following, except for the occasions of damage and slack of the supporting cables, when referring to the supporting cables, the mentioned supporting cables include cable The support cables of the structure and the newly added _M2 sensing cables; the time interval between any two measurements of the same quantity in real time monitoring in this method shall not be greater than 30 minutes, and the time of measuring and recording data is called the actual recording data time The external force borne by objects and structures can be called load, and load includes surface load and body load; surface load is also called surface load, which is a load acting on the surface of an object, including concentrated load and distributed load; body load is continuously distributed in The load of each point inside the object, including the self-weight and inertial force of the object; the concentrated load is divided into two types: concentrated force and concentrated force couple. In the coordinate system including the Cartesian coordinate system, a concentrated force can be decomposed into three Similarly, a concentrated force couple can also be decomposed into three components. If the load is actually a concentrated load, a concentrated force component or a concentrated force couple component is counted or counted as a load in this method. At this time, the load The change of the distributed load is embodied as a concentrated force component or a concentrated force couple component; distributed load is divided into line distributed load and surface distributed load, and the description of distributed load includes at least the action area of distributed load and the size of distributed load Expressed by distribution intensity, distribution intensity is expressed by distribution characteristics and amplitude; if the load is actually a distributed load, when this method talks about the change of load, it actually refers to the change of the amplitude of the distribution intensity of the distributed load, However, the distribution characteristics of the action area and distribution intensity of all distributed loads remain unchanged; in a coordinate system including the Cartesian coordinate system, a distributed load can be decomposed into three components, if the three components of the distributed load If the magnitude of the respective distribution concentration of the components changes, and the rate of change is not all the same, then in this method, the three components of the distributed load are counted or counted as three distributed loads, and one load represents A component of distributed load; body load is the load that is continuously distributed at various points inside the object. The description of body load includes at least the area of action of body load and the size of body load. The size of body load is expressed by the degree of distribution, and the degree of distribution Expressed by distribution characteristics and amplitude; if the load is actually a volume load, what is actually dealt with in this method is the change of the amplitude of the distribution concentration of the body load, while the action area of all body loads and the distribution characteristics of the distribution concentration In this case, the change of the load mentioned in this method actually refers to the change of the magnitude of the distribution concentration of the body load. At this time, the changed load refers to the magnitude of the distribution concentration Body loads that change; in a coordinate system including Cartesian coordinates, a body load can be decomposed into three components, if the magnitude of the distribution of the three components of the body load changes, and the rate of change is not all the same, then in this method, the three components of the body load are counted or counted as three distributed loads; b. This method defines "the temperature measurement and calculation method of the cable structure of this method" according to steps b1 to b3; b1: Query or measure the temperature-dependent heat transfer parameters of the composition materials of the cable structure and the environment where the cable structure is located, use the design drawings, as-built drawings of the cable structure, and the geometrically measured data of the cable structure, and use these data and parameters to establish a cable structure. The heat transfer calculation model of the structure; query the meteorological data of not less than 2 years in recent years where the cable structure is located, and count the number of cloudy days during this period as T cloudy days. In this method, the number of cloudy days that cannot be seen during the day The whole day of the sun is called a cloudy day, and the highest and lowest temperature between 0:00 and 30 minutes after the sunrise time of the next day on each of the T cloudy days is counted. The meteorological sunrise time determined by the sun and the revolution law does not mean that the sun can be seen on that day. You can check the data or calculate the required daily sunrise time through conventional meteorological calculations. Every cloudy day from 0:00 to 19:00 The maximum temperature difference between the highest temperature and the lowest temperature within 30 minutes after sunrise of the next day is called the maximum temperature difference of the daily temperature of the cloudy day. If there are T cloudy days, there will be the maximum temperature difference of the daily temperature of T cloudy days. Take T The maximum value of the maximum temperature difference of daily air temperature in a cloudy day is the reference daily temperature difference, which is recorded as ΔT _r ; query the location of the cable structure and the altitude interval of not less than 2 years of meteorological data in recent years or obtain the cable structure from actual measurements The change data and change law of the temperature of the environment with time and altitude, and the maximum change rate ΔT of the temperature of the environment where the cable structure is located with respect to the altitude in recent years for the location of the cable structure and the altitude interval of not less than 2 years in recent years _h , for the convenience of description, the unit of ΔT _h is ℃/m; take "R cable structure surface points" on the surface of the cable structure, and the specific principle of taking "R cable structure surface points" is described in step b3, and later The temperature of the surface points of the R cable structures will be obtained through actual measurement, and the temperature data obtained from the actual measurement is called "the measured data of the surface temperature of the R cable structures". The temperature of the surface points of the R cable structures is called the calculated temperature data as "calculation data of the surface temperature of the R cable structures"; For less than three different altitudes, at each selected altitude, at least two points are selected at the intersection of the horizontal plane and the surface of the cable structure, and the outer normal of the surface of the structure is indexed from the selected point, all selected The outer normal direction is called "the direction of measuring the temperature distribution of the cable structure along the wall thickness". The direction of temperature distribution along the wall thickness must include the outer normal direction of the sunny surface of the cable structure and the outer normal direction of the shaded surface of the cable structure, and the temperature distribution along the wall thickness of each measurement cable structure is uniform in the cable structure. Select no less than three points, measure the temperature of all selected points, the measured temperature is called "the temperature distribution data of the cable structure along the thickness", in which , "Measuring the direction of the temperature distribution of the cable structure along the wall thickness" measurement obtained "The temperature distribution data of the cable structure along the thickness" is called "the temperature distribution data of the cable structure along the thickness at the same altitude" in this method. It is assumed that H different altitudes are selected, and at each altitude, a In the direction of the temperature distribution of B measuring cable structures along the wall thickness, E points are selected in the cable structure along the direction of the temperature distribution of each measuring cable structure along the wall thickness, where H and E are not less than 3, and B is not less than 2. Let HBE be the product of H, B and E, corresponding to a total of HBE "points for measuring the temperature distribution data of the cable structure along the thickness", which will be obtained through actual measurement later. The measured temperature data is called "HBE cable structure measured temperature data along the thickness", if the heat transfer calculation model of the cable structure is used, the HBE measured cable structure along the thickness can be obtained through heat transfer calculation The temperature at the point of the temperature distribution data is called the calculated temperature data as "HBE cable structure temperature calculation data along the thickness"; let BE be the product of B and E, in this method, there is a total of BE "Temperature distribution data along the thickness of the cable structure at the same altitude"; select a location at the location of the cable structure according to the meteorological temperature measurement requirements, and obtain the actual temperature at this location where the cable structure is located that meets the meteorological temperature measurement requirements; Choose a location in the open and unsheltered place where the cable structure is located. This location should be able to get the fullest sunshine of the day that the location can get every day of the year, and place a carbon steel plate at this location. , called the reference plate. The reference plate cannot be in contact with the ground. The reference plate is no less than 1.5 meters away from the ground. One side of the reference plate faces the sun, which is called the sunny side. The sunny side of the reference plate is rough and dark. The reference plate The sunny side of the reference plate should be able to get the fullest sunlight that a slab can get in that day every day of the year. The non-sunny side of the reference slab is covered with thermal insulation material, and the slab’s sunny side will be obtained through real-time monitoring. surface temperature; b2: Obtain the measured surface temperature data of the R cable structures at the surface points of the above R cable structures through real-time monitoring, and at the same time obtain the temperature distribution data of the previously defined cable structures along the thickness through real-time monitoring. The temperature data of the environment where the structure is located; through real-time monitoring, the temperature measured data series of the environment where the cable structure is located is obtained from the sunrise time of the day to 30 minutes after the sunrise time of the next day. The measured temperature data of the environment where the cable structure is located between the time and 30 minutes after sunrise of the next day are arranged in chronological order, and the highest temperature and the lowest temperature in the air temperature measurement data sequence of the environment where the cable structure is located are found. The maximum temperature difference in the air temperature measured data sequence minus the minimum temperature is the maximum temperature difference between the sunrise time of the day and 30 minutes after the sunrise time of the next day in the environment where the cable structure is located, which is called the maximum temperature difference of the environment, and is recorded as ΔT _emax ; The temperature measured data sequence of the environment where the cable structure is located is obtained through conventional mathematical calculations. The measured data series of the temperature of the sunny side of the reference plate between 30 minutes, the measured data series of the temperature of the sunny side of the reference plate from the sunrise time of the current day to the sunny side of the reference plate 30 minutes after the sunrise time of the next day The measured data of the temperature of the reference plate are arranged in chronological order, find the highest temperature and the lowest temperature in the measured data sequence of the temperature of the sunny side of the reference plate, and subtract the lowest temperature from the highest temperature in the measured data sequence of the temperature of the sunny side of the reference plate Temperature obtains the maximum temperature difference between the sunrise time of the day and 30 minutes after the sunrise time of the next day from the temperature of the sunny side of the reference plate, which is called the maximum temperature difference of the reference plate, and is recorded as ΔT _pmax ; The measured data series of cable structure surface temperature of all R cable structure surface points between 30 minutes after the sunrise time of the next day, there are R cable structure surface temperature measured data series of R cable structure surface points, each cable structure The measured data sequence of the surface temperature is arranged in chronological order by the measured data of the surface temperature of the cable structure between the sunrise time of the day and 30 minutes after the sunrise time of the next day at a surface point of the cable structure, and the measured data sequence of the surface temperature of each cable structure is found From the highest temperature and the lowest temperature in the data series, subtract the lowest temperature from the highest temperature in the measured data series of the surface temperature of each cable structure to obtain the temperature of each cable structure surface point from the sunrise time of the day to 30 minutes after the sunrise time of the next day If there are R surface points of the cable structure, there are R maximum temperature difference values between the sunrise time of the day and 30 minutes after the sunrise time of the next day, and the maximum value is called the maximum temperature difference of the cable structure surface, which is denoted as ΔT _smax ; From the measured data sequence of the surface temperature of each cable structure, the rate of change of the temperature of each cable structure surface point with respect to time is obtained through conventional mathematical calculations, and the temperature of each cable structure surface point with respect to time The rate of change also changes with time; after obtaining HBE "temperature distribution data along the thickness of the cable structure" at the same time between the sunrise time of the day and 30 minutes after the sunrise time of the next day through real-time monitoring, calculate the The difference between the maximum temperature and the minimum temperature in a total of BE "temperature distribution data of the cable structure along the thickness at the same altitude" at a selected altitude, the absolute value of this difference is called "thickness direction of the cable structure at the same altitude". If H different altitudes are selected, there will be H "maximum temperature differences in the thickness direction of the cable structure at the same altitude", and the maximum value of the H "maximum temperature differences in the thickness direction of the cable structure at the same altitude" is "The maximum temperature difference in the thickness direction of the cable structure", denoted as ΔT _tmax ; b3: Measurement and calculation to obtain the steady-state temperature data of the cable structure; firstly, determine the moment to obtain the steady-state temperature data of the cable The time of the structural steady-state temperature data is between the sunset time of the current day and 30 minutes after the sunrise time of the next day. The sunset time refers to the meteorological sunset time determined according to the laws of the earth's rotation and revolution. You can query the data or through the conventional weather The required sunset time of each day can be obtained through scientific calculation; the second condition a condition is that during the period between the sunrise time of the current day and 30 minutes after the sunrise time of the next day, the maximum temperature difference ΔT _pmax and the maximum temperature difference of the reference plate The maximum temperature difference ΔT _smax on the surface of the cable structure is not greater than 5 degrees Celsius; the b condition of the second condition is that during the period between the sunrise of the day and 30 minutes after the sunrise of the next day, in the environment obtained by the previous measurement and calculation The maximum error ΔT _emax is not greater than the reference daily temperature difference ΔT _r , and the maximum temperature difference ΔT _pmax of the reference plate minus 2 degrees Celsius is not greater than ΔT _emax , and the maximum temperature difference ΔT _smax on the surface of the cable structure is not greater than ΔT _pmax ; it only needs to satisfy the second item a One of the condition and b condition is said to meet the second condition; the third condition is that at the moment when the steady-state temperature data of the cable structure is obtained, the absolute value of the temperature change rate of the environment where the cable structure is located with respect to time is not greater than each 0.1 degrees Celsius per hour; the fourth condition is that at the moment when the steady-state temperature data of the cable structure is obtained, the absolute value of the temperature change rate of each cable structure surface point in the R cable structure surface points with respect to time is not greater than 0.1 degrees Celsius per hour The fifth condition is that at the moment when the steady-state temperature data of the cable structure is obtained, the measured data of the cable structure surface temperature of each cable structure surface point in the R cable structure surface points is from the sunrise time of the day to the day after the sunrise time of the next day The minimum value between 30 minutes; the sixth condition is that at the moment when the steady-state temperature data of the cable structure is obtained, the "maximum temperature difference in the thickness direction of the cable structure" ΔT _tmax is not greater than 1 degree Celsius; this method utilizes the above six conditions, and the following Any one of the three kinds of time is called "mathematical time for obtaining the steady-state temperature data of the cable structure". Item 1 to item 5 conditions, the second type of time is the time that only meets the sixth condition in the above "conditions related to the time to determine the time to obtain the steady-state temperature data of the cable structure", and the third type of time is when the above-mentioned conditions are met at the same time The moment of the first item to the sixth condition in "Conditions related to the moment of determining the time to obtain the steady-state temperature data of the cable structure"; For one hour, the moment of obtaining the steady-state temperature data of the cable structure is the mathematical moment of obtaining the steady-state temperature data of the cable structure; Take the method closest to the mathematical moment of obtaining the steady-state temperature data of the cable structure The moment when the data is actually recorded is the moment when the steady-state temperature data of the cable structure is obtained; this method will use the amount measured and recorded at the moment when the steady-state temperature data of the cable structure is obtained to perform cable structure-related health monitoring analysis; this method approximately considers that the obtained cable structure The temperature field of the cable structure at the moment of the steady-state temperature data is in a steady state, that is, the temperature of the cable structure at this moment does not change with time, and this moment is the "moment of obtaining the steady-state temperature data of the cable structure" of this method; Thermal characteristics, using the "measured surface temperature data of R cable structures" and "measured data of temperature along the thickness of HBE cable structures" at the time when the steady-state temperature data of cable structures are obtained, using the heat transfer calculation model of cable structures, through conventional The thermal calculation obtains the temperature distribution of the cable structure at the moment when the steady-state temperature data of the cable structure is obtained. At this time, the temperature field of the cable structure is calculated according to the steady state. The temperature distribution data includes the calculated temperature of R cable structure surface points on the cable structure, and the calculated temperature of the R cable structure surface points is called the R cable structure steady-state surface temperature calculation data, and also includes the HBE selected in front of the cable structure. The calculation temperature of "points for measuring the temperature distribution data of the cable structure along the thickness", the calculation temperature of HBE "points for measuring the temperature distribution data of the cable structure along the thickness" is called "HBE temperature calculation data of the cable structure along the thickness", when When the measured data of the surface temperature of R cable structures is equal to the calculated data of the steady-state surface temperature of R cable structures, and the "measured data of the temperature along the thickness of the HBE cable structures" is correspondingly equal to the "calculated data of the temperature along the thickness of the HBE cable structures" , the calculated temperature distribution data of the cable structure at the moment when the cable structure steady-state temperature data is obtained is called "cable structure steady-state temperature data" in this method, and the "R cable structure surface temperature measured data" at this time is called is the "measured data of the steady-state surface temperature of R cable structures", and the "measured data of the temperature of the HBE cable structures along the thickness" is called "the measured data of the steady-state temperature of the HBE cable structures along the thickness"; cable structure surface points", the number and distribution of "R cable structure surface points" must meet three conditions. The first condition is that when the cable structure temperature field is in a steady state, when the temperature of any point on the cable structure surface When it is obtained by the linear interpolation of the measured temperature of the point adjacent to the arbitrary point on the surface of the cable structure among the "R cable structure surface points", the temperature of the arbitrary point on the surface of the cable structure obtained by linear interpolation is the same as the temperature of the arbitrary point on the surface of the cable structure The error of the actual temperature at any point is not greater than 5%; the surface of the cable structure includes the surface of the supporting cable; the second condition is that the number of points at the same altitude in the "R cable structure surface points" is not less than 4, and "R The points at the same altitude in "Cable Structure Surface Points" are evenly distributed along the cable structure surface; the absolute value of the difference in altitude between all pairwise adjacent cable structure surface points along the altitude of "R Cable Structure Surface Points" The maximum value of Δh is not greater than 0.2°C divided by ΔT _h . For the convenience of description, the unit of ΔT _h is ℃/m. For the convenience of description, the unit of Δh is m; "R The definition of two adjacent cable structure surface points along the altitude of the cable structure surface point means that when only the altitude is considered, there is no cable structure surface point in the "R cable structure surface points", and the cable structure surface point The altitude value of the cable structure is between the altitude values of two adjacent cable structure surface points; the third condition is to query or calculate according to meteorological routines to obtain the sunshine law of the cable structure location and the altitude interval, and then according to the cable structure Geometric features and azimuth data, find the positions of those surface points on the cable structure that receive the most sunshine time throughout the year, at least one cable structure surface point in the "R cable structure surface points" is the annual sunshine time on the cable structure one of those surface points that is most adequate; c. According to the "temperature measurement and calculation method of the cable structure of this method", the steady-state temperature data of the cable structure in the initial state is directly measured and calculated, and the steady-state temperature data of the cable structure in the initial state is called the initial steady-state temperature data of the cable structure. It is recorded as "initial cable structure steady-state temperature data vector T _o "; the physical and mechanical performance parameters of various materials used in the cable structure that vary with temperature are obtained from actual measurement or information; the initial cable structure steady-state temperature data vector is obtained from the actual measurement At the same moment T _o , the initial cable forces of all supporting cables are directly measured and calculated to form the initial cable force vector F _o ; according to the data including cable structure design data and completed data, all supporting cables are in the free state, that is, the cable force is The length at 0, the cross-sectional area in the free state and the weight per unit length in the free state, as well as the temperature of all supporting cables when these three data are obtained, on this basis, the temperature-dependent Physical performance parameters and mechanical performance parameters, according to conventional physical calculations, the lengths of all supporting cables when the cable force is 0 and the lengths of all supporting cables when the cable force is 0 under the condition of the initial cable structure steady-state temperature data vector T _o The cross-sectional area and the weight per unit length of all supporting cables when the cable force is 0 form the initial free length vector of the supporting cables, the initial free cross-sectional area vector and the weight vector of the initial free unit length, and the initial free length vector of the supporting cables , the initial free cross-sectional area vector and the initial free unit length weight vector have the same numbering rules as the elements of the initial cable force vector _{F o} ; At the same moment of the state temperature data vector T _o , the measured data of the initial cable structure are directly measured and calculated, and the measured data of the initial cable structure include the concentrated load measurement data of the cable structure, the distributed load measurement data of the cable structure, and the body load measurement data of the cable structure data, initial values of all monitored quantities, initial cable force data of all supporting cables, initial cable structure modal data, initial cable structure strain data, initial cable structure geometry data, initial cable structure support generalized coordinate data, initial cable structure The measured data including the angle data and the initial cable structure space coordinate data, the generalized coordinate data of the initial cable structure support include the space coordinate data of the initial cable structure support and the initial cable structure support angular coordinate data, after obtaining the measured data of the initial cable structure At the same time, the data that can express the health state of the support cable including the non-destructive testing data of the support cable are obtained through measurement and calculation. At this time, the data that can express the health state of the support cable is called the initial health state data of the support cable; all monitored The initial value of the quantity constitutes the initial value vector C _o of the monitored quantity, and the numbering rule of the initial value vector C _o of the monitored quantity is the same as that of the M monitored quantities; it is established by using the initial health state data of the supporting cable and the load measurement data of the cable structure The initial damage vector d _o of the evaluated object, the vector d _o represents the initial health state of the evaluated object of the cable structure represented by the initial mechanical calculation benchmark model A _o ; The number of elements of the damage vector d _o is equal to N, and the elements of d _o have a one-to-one correspondence with the evaluated object. The numbering rule of the elements of the vector d _o is the same as that of the evaluated object; if a certain element of d _o corresponds to The object to be evaluated is a supporting cable in the cable system, then the value of this element of d _o represents the initial damage degree of the corresponding supporting cable, if the value of this element is 0, it means that the supporting cable corresponding to this element is intact , without damage, if its value is 100%, it means that the supporting cable corresponding to this element has completely lost its bearing capacity; if its value is between 0 and 100%, it means that the supporting cable has lost its corresponding proportion of bearing capacity capacity; if a certain element of d _o corresponds to a certain load, the value of this element of d _o is taken as 0 in this method, which means that the initial value of the change of this load is 0; if there is no non-destructive testing of supporting cables data and other data that can express the health state of the supporting cable, or when the initial state of the structure can be considered as a state of no damage and no relaxation, the value of each element related to the supporting cable in the vector d _o is 0; the generalized coordinates of the initial cable structure support The data constitute the generalized coordinate vector U _o of the initial cable structure support; d. According to the design drawing of the cable structure, the as-built drawing and the actual measurement data of the initial cable structure, the initial health status data of the supporting cable, the measurement data of the concentrated load of the cable structure, the measurement data of the distributed load of the cable structure, the measurement data of the body load of the cable structure, and the data of the cable structure. The physical and mechanical performance parameters of various materials used as a function of temperature, the initial cable structure support generalized coordinate vector U _o , the initial cable structure steady-state temperature data vector T _o and all the cable structure data obtained in the previous steps, to establish the calculation The initial mechanical calculation benchmark model A _o of the cable structure is entered into the "steady-state temperature data of the cable structure". The calculated data of the cable structure based on A _o must be very close to the measured data, and the difference between them shall not be greater than 5%; corresponding to A _o The "cable structure steady-state temperature data" is the " _initial cable structure steady-state temperature data vector T _o "; the health state of the evaluated object corresponding to A _o is represented by the initial damage vector d _o of the evaluated object; The initial value of the monitored quantity is represented by the initial value vector C _o of the monitored quantity; for the first time, the current initial mechanical calculation benchmark model A ^t _o of the cable structure included in the "steady-state temperature data of the cable structure" is established, and the current initial value of the monitored quantity Numerical vector C ^t _o and “current initial cable structure steady-state temperature data vector T ^t _o ”; when the current initial mechanical calculation benchmark model A ^t _o of the cable structure and the current initial numerical vector C ^t _o of the monitored quantity are established for the first time, The current initial mechanical calculation benchmark model A ^t _o of the cable structure is equal to the initial mechanical calculation benchmark model A _o of the cable structure, and the current initial numerical vector C ^t _o of the monitored quantity is equal to the initial numerical vector C _o of the monitored quantity; A ^t _o corresponds to The "steady-state temperature data of the cable structure" is called "the current initial steady-state temperature data of the cable structure", which is recorded as "the vector T ^t _o of the current initial steady-state temperature data of the cable structure", and the current initial mechanical calculation of the cable structure is established for the first time When the benchmark model A ^t _o , T ^t _o is equal to T _o ; the generalized coordinate data of the cable structure support corresponding to the current initial mechanical calculation benchmark model A ^t _o of the cable structure constitutes the current initial cable structure support generalized coordinate vector U ^t _o , when the current initial mechanical calculation benchmark model A ^t _o of the cable structure is established for the first time, U ^t _o is equal to U _o ; the initial health state of the evaluated object of A ^t _o is the same as that of the evaluated object of A _o , It is also represented by the initial damage vector d _o of the evaluated object, and the initial health state of the evaluated object of A ^t _o is always represented by the initial damage vector d _o of the evaluated object in the following cycle; T _o , U _o and d _o are The parameters of A _o , the initial values of all the monitored quantities obtained from the mechanical calculation results of A _o are the same as the initial values of all the monitored quantities represented by C _o , so it can also be said that C _o is composed of the mechanical calculation results of A _o ; T ^t _o , U ^t _o and d _o are the parameters of A ^t _o , and C ^t _o is composed of the mechanical calculation results of A ^t _o ; e. From here, enter the cycle from step e to step n; during the service process of the structure, continuously measure and calculate according to the "temperature measurement and calculation method of the cable structure of this method" to obtain the current value of the "steady-state temperature data of the cable structure" data, the current data of "cable structure steady-state temperature data" is called "current cable structure steady-state temperature data", recorded as "current cable structure steady-state temperature data vector T ^t ", the definition of vector T ^t is the same as that of vector T _o are defined in the same way; at the same moment when the current steady-state temperature data vector T ^t of the cable structure is obtained from the actual measurement, the current data of the generalized coordinates of the cable structure supports are obtained from the actual measurement, and the current data of all the generalized coordinates of the cable structure supports form the generalized The coordinate vector U ^t , the definition of the vector U ^t is the same as the definition of the vector U _o ; when the current cable structure steady-state temperature data vector T ^t is obtained from the actual measurement, the newly added M ₂ sensing cables are non-destructively tested. Identify the damaged or slack sensory cords, and remove the corresponding sensory cords that are identified as damaged or slack from the vectors numbered according to the monitored quantity numbering rules that appear before the method according to the numbering rules of the monitored quantities. The elements of the vectors and matrices that appear after this method no longer appear corresponding to the identified damaged or slack sensory cords. When referring to the sensory cords after this method, the identified elements are no longer included here. Damaged or slack sensor cables, the cable force of the sensor cables identified as damage or slack here will no longer be included when referring to the monitored quantity after this method; If the sensing cable is loose, reduce M ₂ and M by the same amount; at the same moment when the steady-state temperature data vector T ^t of the current cable structure is measured, the measured cable force data of all M ₁ supporting cables in the cable structure , all these cable force data form the current cable force vector F, and the elements of the vector F have the same numbering rules as the elements of the vector F _o ; at the same moment when the current steady-state temperature data vector T ^t of the cable structure is obtained from the actual measurement, all M _The spatial coordinates of the two supporting end points of a supporting cable, the difference between the spatial coordinates of the two supporting end points in the horizontal direction is the horizontal distance between the two supporting end points, and the horizontal distance data of the two supporting end points of all the supporting cables constitute the current supporting cable two The horizontal distance vector of the support end points, the numbering rule of the elements of the horizontal distance vector between the two support end points of the current support cable is the same as the numbering rule of the elements of the initial cable force vector F _o ; f. According to the current cable structure measured support generalized coordinate vector U ^t and the current cable structure steady-state temperature data vector T ^t , follow steps f1 to f3 to update the current initial mechanical calculation benchmark model A ^t _o and the current initial cable structure support generalized coordinates Vector U ^t _o , the current initial value vector C ^t _o of the monitored quantity and the current initial cable structure steady-state temperature data vector T ^t _o ; f1. Compare U ^t with U ^t _o , T ^t with T ^t _o respectively, if U ^t is equal to U ^t _o and T ^t is equal to T ^t _o , then A ^t _o , U ^t _o , C ^t _o and T ^t _o remain Otherwise, A ^t _o , U ^t _o and T ^t _o need to be updated according to the following steps; f2. Calculate the difference between U ^t and U _o . The difference between U ^t and U _o is the generalized displacement of the cable structure support relative to the initial position. Use the generalized displacement vector V of the support to represent the generalized displacement of the support. V is equal to U ^t minus Remove U _o , there is a one-to-one correspondence between the elements in the generalized displacement vector V of the support and the generalized displacement components of the support, and the value of an element in the generalized displacement vector V of the support corresponds to the generalized value of a specified direction of a specified support Displacement; calculate the difference between T ^t and T _o , the difference between T ^t and T _o is the change of the current cable structure steady-state temperature data with respect to the initial cable structure steady-state temperature data, the difference between T ^t and T _o uses the steady-state temperature change vector S means that S is equal to T ^t minus T _o , and S means the change of the steady-state temperature data of the cable structure; f3. First apply the support generalized displacement constraint to the cable structure support in A _o , the value of the support generalized displacement constraint is taken from the value of the corresponding element in the support generalized displacement vector V, and then apply the support to the cable structure in A _o temperature change, the value of the applied temperature change is taken from the steady-state temperature change vector S, the generalized displacement constraint of the support is applied to the support of the cable structure in A _o and the updated current is obtained after the temperature change is applied to the cable structure in A _o The initial mechanical calculation benchmark model A ^t _o , when A ^t _o is updated, the value of all elements of U ^t _o is also replaced by the corresponding value of all elements of U ^t , that is, U ^t _o is updated, and the value of all elements of T ^t _o is also replaced by the value of T ^t All element values are replaced accordingly, that is, T ^t _o is updated, so that T ^t _o and U ^t _o corresponding to ^A t o are obtained correctly; the method of updating C ^t _o is: after updating A ^t _{o ,} through mechanics The current specific values of all the monitored quantities in A ^t _o are calculated, and these specific values constitute C ^t _o ; the initial health state of the supporting cable of A ^t _o is always represented by the initial damage vector d _o of the evaluated object; g. On the basis of the current initial mechanical calculation benchmark model A ^t _o , perform several mechanical calculations according to steps g1 to g4, and obtain the numerical change matrix ΔC of the monitored quantity of cable structure unit damage and the unit change vector D _u of the evaluated object through calculation; g1. The value change matrix ΔC of the monitored quantity of cable structure unit damage is constantly updated, that is, the current initial mechanical calculation benchmark model A ^t _o , the current initial cable structure support generalized coordinate vector U ^t _o , and the current initial value of the monitored quantity After the vector C ^t _o and the current initial cable structure steady-state temperature data vector T ^t _o , the cable structure unit damage value change matrix ΔC and the unit change vector D _u of the evaluated object must be updated; g2. Carry out several mechanical calculations on the basis of the current initial mechanical calculation benchmark model A ^t _o of the cable structure. The number of calculations is numerically equal to the number N of all evaluated objects. There are N evaluation objects and there are N calculations; The numbering rules of the evaluation objects are calculated sequentially; each calculation assumes that there is only one evaluated object, and the unit damage or load unit change is added on the basis of the original damage or load. Specifically, if the evaluated object is a cable system If the supporting cable is rooted, then it is assumed that the supporting cable will add _unit damage on the basis of the existing damage of the supporting cable represented by the vector d _o . If the object to be evaluated is a load, it is assumed that the Add the change of load unit on the basis of the existing change of load, and use D _uk to record the increased unit damage or load unit change, where k represents the number of the evaluated object that increases the unit damage or load unit change, and D _uk is the An element of the unit change vector D _u of the evaluated object, the numbering rule of the elements of the unit change vector D _u of the evaluated object is the same as that of the elements of the vector d _o ; the evaluated object of the unit damage or load unit change is added in each calculation Different from the evaluated objects that increase unit damage or load unit changes in other calculations, each calculation uses the mechanical method to calculate the current calculation values of all monitored quantities of the cable structure, and the current calculation values of all monitored quantities obtained from each calculation Values form a monitored quantity to calculate the current vector, and the element numbering rule of the monitored quantity to calculate the current vector is the same as the element numbering rule of the initial value vector C _o of the monitored quantity; g3. Calculate the current vector of the monitored quantity obtained by each calculation and subtract the current initial value vector C ^t _o of the monitored quantity to obtain a vector, and then divide each element of the vector by the unit damage or load assumed for this calculation Unit change value, get a monitored quantity unit change vector, if there are N evaluated objects, there will be N monitored quantity unit change vectors; g4. According to the numbering rules of the N evaluated objects, the change vectors of the N monitored quantity units are sequentially formed into a numerical change matrix ΔC of the monitored quantity damage of the cable structure unit with N columns; the numerical change matrix of the monitored quantity damage of the cable structural unit Each column of ΔC corresponds to a monitored quantity unit change vector; each row of the cable structure unit damage monitored quantity value change matrix ΔC corresponds to the difference of the same monitored quantity when different evaluated objects increase unit damage or load unit changes The unit change range of the cable structure unit damage value change matrix ΔC is the same as the numbering rule of the elements of the vector d _o , and the row numbering rule of the cable structure unit damage value change matrix ΔC is the same as that of M The numbering rules of the monitored quantities are the same; h. Obtaining ^the current measured values of all monitored quantities of the cable structure at the same moment when the current cable structure steady-state temperature data vector T ^t is obtained through actual measurement, Composing the current numerical vector C of the monitored quantity; the current numerical vector C of the monitored quantity and the current initial numerical vector C ^t _o of the monitored quantity are defined in the same way as the initial numerical vector C _o of the monitored quantity, and the elements of the same number of the three vectors represent Specific values of the same monitored quantity at different times; i. Define the current nominal damage vector d of the evaluated object, the number of elements of the current nominal damage vector d of the evaluated object is equal to the number of evaluated objects, and the elements of the current nominal damage vector d of the evaluated object and the evaluated object are one by one Corresponding relationship, the element value of the current nominal damage vector d of the evaluated object represents the nominal damage degree or nominal load change of the corresponding evaluated object; the numbering rule of the elements of the vector d is the same as that of the elements of the vector d _o ; j. According to the approximate linearity existing between the current numerical vector C of the monitored quantity and the current initial numerical vector C ^t _o of the monitored quantity, the numerical change matrix ΔC of the monitored quantity damaged by the cable structure unit, and the current nominal damage vector d of the evaluated object to be obtained The approximate linear relationship can be expressed as formula 1. In formula 1, other quantities except d are known, and the current nominal damage vector d of the evaluated object can be calculated by solving formula 1; $C=C_o^t+\mathrm{\&Delta;C}\&Center\; Dot;d$ Formula 1 k. Define the current actual damage vector d ^a of the evaluated object, the number of elements of the current actual damage vector d ^a of the evaluated object is equal to the number of evaluated objects, and the distance between the elements of the current actual damage vector d ^a of the evaluated object and the evaluated object It is a one-to-one correspondence relationship, the element value of the current actual damage vector d ^a of the evaluated object represents the actual damage degree or actual load change of the corresponding evaluated object; the numbering rule of the elements of the vector d ^a is the same as the numbering rule of the elements of the vector d _o same; l. The k-th element d a k of the current actual damage vector d ^a of the evaluated object expressed by formula 2 is the same as _the k-th element ^d _ok of the initial damage vector d _o of the evaluated object and the current nominal damage vector d of the evaluated object The relationship between the kth element d _k is calculated to obtain all the elements of the current actual damage vector d ^a of the evaluated object;

In formula 2, k=1,2,3,...,N, d ^a _k represents the current actual health status of the kth evaluated object, and when d ^a _k is 0, it means that the kth evaluated object has no health problems, When the value of d ^a _k is not 0, it means that the kth evaluated object is an evaluated object with health problems. If the evaluated object is a supporting cable in the cable system, then d ^a _k represents the severity of its current health problem The supporting cables with health problems may be slack cables or damaged cables, and the d ^a _k value reflects the degree of slack or damage of the supporting cables; the damaged cables can be identified from these supporting cables with health problems , the rest is the slack cable, the value of the elements corresponding to the slack cable in the current actual damage vector d ^a of the evaluated object expresses the current actual equivalent damage degree mechanically equivalent to the relaxation degree of the slack cable; if the evaluated object is a load, then d ^a _k represents the actual variation of the load; m. Utilize the slack cables identified in the first step under the condition of the current steady-state temperature data vector T ^t of the cable structure and the mechanics of these slack cables expressed by the current actual damage vector d ^a of the evaluated object and their degree of relaxation, etc. The effective current actual equivalent damage degree, using the current cable force vector F and the horizontal distance vector between the two supporting ends of the current cable structure under the condition of the current cable structure steady-state temperature data vector T ^t obtained in step e, using the The initial free length vector of the supporting cable, the initial free cross-sectional area vector, the initial free unit length weight vector, and the initial cable force vector F _o under the condition of the initial cable structure steady-state temperature data vector T _o obtained in the first step, using the current cable The current steady-state temperature data of the support cable represented by the structural steady-state temperature data vector T ^t is used to obtain the initial steady-state temperature data of the support cable represented by the initial cable structure steady-state temperature data vector T _o obtained in the cth step, and the c The temperature-dependent physical and mechanical performance parameters of various materials used in the cable structure obtained in the first step, taking into account the influence of temperature changes on the physical, mechanical and geometric parameters of the supporting cable, through the mechanical equivalent of the slack cable and the damaged cable To calculate the relaxation degree equivalent to the current actual equivalent damage degree of the slack cable, the mechanical equivalent conditions are: the initial free length, geometric characteristic parameters, density and The mechanical characteristic parameters of the material are the same; 2. After relaxation or damage, the cable force and the total length after deformation of the two equivalent slack cables and damaged cables are the same; when the above two mechanical equivalent conditions are met, such two supporting cables The mechanical functions in the cable structure are exactly the same, that is, if the damaged cable is replaced by an equivalent slack cable, the cable structure will not change, and vice versa; The degree of slack of the cables, the degree of slack is the change in the free length of the supporting cables, that is, the adjustment of the cable lengths of the supporting cables whose force needs to be adjusted is determined; in this way, the slack identification and damage identification of the supporting cables are realized; The required cable force is given by the corresponding elements of the current cable force vector F; in this method, damaged cables and slack cables are collectively referred to as support cables with health problems, referred to as problem cables. Therefore, this method is based on the current actual damage vector d of the evaluated object ^a. It can not only identify the problem cable, but also determine which loads have changed and the value of the change; so far, this method has realized the problem cable identification of the cable structure by eliminating the influence of the generalized displacement of the support, load change and structural temperature change , and at the same time realize the identification of the load variation which excludes the influence of the generalized displacement of the support, the structure temperature change and the health state change of the support cable; n. Go back to step e and start the next cycle from step e to step n.