JPH05157655A - On-line earthquake response load experiment device - Google Patents

Abstract

PURPOSE:To achieve a truthful reproduction as a time-series waveform when an earthquake wave is proportional to a real time by always making constant an addition count of an increment of a force-application command value and an output time step. CONSTITUTION:An actually measured load by a load detector 3 is used as a retrieval force the number of divisions up to a target value and each divided output time step are always made constant by a high-speed operation device 8, and then the target value is allowed to be exceeded when the error content is added to the next force-application command value and the force-applied displacement step is multiplied by the number of divisions when an increment of an actual displacement is small in increment of the force-application command value, thus enabling the earthquake wave to be reproduced truthfully as a time-series waveform which is proportionately multiples of the real time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-line seismic response loading experiment apparatus in which a loading experiment apparatus is incorporated in an arithmetic and control system, and in particular, an on-line suitable for reproducing seismic waves as time-series waveforms that are proportional to real time. Earthquake response loading test equipment.

[0002]

2. Description of the Related Art Conventionally, various experiments have been conducted to examine how a structure sways and breaks during a large earthquake. For example, in September 1983, published by the Japan Institute of Architecture "Academic Conference Lecture Summary of Lectures, pages 1395 and 1396 about speeding up of computer-test machine online system" An earthquake-resistant experimental system that organically combines experiments with seismic response analysis using a digital computer is introduced. In the system, the increment of the force command value to the next target point calculated using the restoring force of the device under test measured as a signal from the load detector and its output time are always constant, The increase is added to the force command value until the measured displacement passes through the target point previously obtained. More detailed description is as follows.

FIG. 3 is a schematic diagram for explaining the operation at the time of force control by the above method. As shown in the figure, since the increment Δr of the force command value and the increment time Δtm of the force command are constant, the increment Δr of the force command value and the force command value are obtained by the mathematical formulas 1 and 2.

[0004]

[Equation 1]

[0005]

[Equation 2]

As a device related to this type, for example, "Development of an online seismic response test system of the Kanto chapter research report of the Architectural Institute of Japan, 1986" is cited. The above is for stopping the error in each force step and discriminating the error, and is not for the purpose of reproducing the time-series waveform. Therefore, detailed description will be omitted.

[0007]

In the above-mentioned prior art, the increment of the force command value and its output time increment are constant, and the force command value increases until the actual displacement of the DUT passes the target point. Since the minutes are added, there is no consideration to keep the number of additions until reaching the target point constant, and there is a problem that the seismic wave cannot be reproduced as a time-series waveform that is proportional to the real time.

An object of the present invention is to make it possible to faithfully reproduce the seismic wave as a time-series waveform in which the number of additions of the increment of the force command value and the output time step are always constant and the seismic wave is proportional to the real time. It is to provide a response loading test device.

[0009]

In order to achieve the above object, the present invention provides a vibrator for applying a force to a test object, a load detector for detecting a load applied by the vibrator, and A displacement detector that detects the amount of displacement of the test body, and a high-speed arithmetic device that calculates the vibration equation by capturing the load and displacement from the load detector and the displacement detector online are provided. In the online seismic response loading test equipment that does not require numerical modeling of the restoring force characteristics, the load measured by the load detector is used as the restoring force, and the displacement measured by the displacement detector is used to calculate the high speed. If the number of divisions to the next target point and the output time step are always constant in the arithmetic unit, and the increment of the actual displacement is small with respect to the increment of the force command value, the error is calculated as the next force command. Add to the value, Waves is obtained by a reproducible as time-series waveform of a proportional multiple of the real time.

The above-mentioned force displacement steps are
It is set to exceed the above target value.

[0011]

Since the present invention is constructed as described above,
The number of divisions in one force step and the output time step of the force command value are always kept constant. If the increment of the actual displacement is small with respect to the increment of the force command value, the error is calculated as follows. The target value can be exceeded when it is added to the force command value of, and the predetermined number of divisions is performed, so that the seismic wave recorded by constant sampling can be reproduced as a time series waveform that is proportional to the real time. ..

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing an online seismic response loading experiment device which is an embodiment of the present invention, and FIG. 2 is a schematic diagram for explaining the operation during force control according to the present invention.

In FIG. 1, reference numeral 1 denotes a structure to be tested, which is a target of a load test. Reference numeral 2 denotes an exciter installed at one end of the device under test 1, which is composed of, for example, a hydraulic jack and the like. The load inspection device 3 for detecting the load applied to the machine 1 is provided. Reference numeral 4 denotes a displacement detector installed at the other end of the device under test 1, which detects the amount of displacement when the device under test 1 is loaded by the vibrator 2. A load feedback circuit 5 digitally converts the load amount from the load inspector 3 and feeds back the digital load signal to the high-speed arithmetic unit 8 or the servo amplifier 7. A displacement feedback circuit 6 digitally converts the displacement amount from the displacement detector 4 and feeds back the digital displacement signal to the high speed computing device 8. The high speed computing device 8 obtains the next target point based on the digital load signal and the digital displacement signal,
The force command value is output to the servo amplifier 7. The servo amplifier 7 amplifies the force command value and outputs it to the vibrator 2.

Next, the operation will be described.

The vibration exciter 2 applies a force to the DUT 1, the load detector 3 determines the restoring force of the load at this time, and the displacement detector 4 detects the amount of displacement of the DUT. Feedback is online to the high-speed arithmetic unit 8 via the load feedback circuit 5 and the displacement feedback circuit 6, respectively. The high-speed arithmetic unit 8 uses the actual seismic wave acceleration data recorded at a certain minute time interval (sampling time interval) as an input seismic wave to perform a numerical analysis of a vibration equation. For example, the central difference method is adopted as the numerical integration method of the vibration method, and in the case of the one-degree-of-freedom system, calculation is performed by the recurrence formula regarding the response displacement represented by the following Expression 3, and the target value of the next step is obtained.

[0016]

[Equation 3]

FIG. 2 shows a force control method up to the target value obtained by the above equation 3. As shown in the figure, the number of divisions in one step is always constant. Therefore, even if the target value is reached at an early stage, the force applied to the device under test 1 continues without being terminated. Also, when the target value is not reached as a result, it is allowed. When the increment of the actual displacement is small with respect to the force command value at each force point obtained by dividing one step, the error amount is added to the next force command value. After outputting the force command value for one step, the restoring force (load) and the displacement are detected by the load inspecting device 3 and the displacement inspecting device 4, respectively. In this case, the load value detected by the load inspector 3 is not the restoring force corresponding to the target value in the strict sense, but this value is used for the calculation.

In FIG. 2, the number of divisions in one step is m
Then, the step of the applied displacement is determined as in the following equation 4 so that the target value is always exceeded at the n-th time.

[0019]

[Equation 4]

Here, the increment of the force command value, the force command value, and the time increment of the force are calculated by the following equations 5, 6, and 7.

[0021]

[Equation 5]

[0022]

[Equation 6]

[0023]

[Equation 7]

Therefore, the time required to take in the restoring force by the high-speed arithmetic unit 8 and output the force command value represented by the formula 6 as the target value of the next step and the force time step represented by the formula 7 are as follows. It becomes number 8.

[0025]

[Equation 8]

As described above, according to the online seismic response loading experimental apparatus according to this embodiment, the force displacement step shown by the equation (4) and the vibration command value shown by the equation (5) always exceed the target value. It is possible to reproduce the input seismic wave as a time-series waveform that is proportionally multiplied by real time by outputting with the same period and the same number of divisions, and the strength of the structure can be easily measured.

[0027]

According to the present invention, the force can be controlled by keeping the number of divisions to the next target point calculated using the restoring force of the structure under test and the output time step constant. Therefore, the seismic wave can be reproduced as a time-series waveform by multiplying the real time by a proportional multiple, and the strength of the structure can be easily measured.

[Brief description of drawings]

FIG. 1 is a block diagram showing an online seismic response load carrying device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining an operation during force control according to the present invention.

FIG. 3 is a schematic diagram for explaining an operation during force control by a conventional method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... DUT, 2 ... Vibrator, 3 ... Load detector, 4 ... Displacement detector, 5 ... Load feedback circuit, 6 ... Displacement feedback circuit, 7 ... Servo amplifier, 8 ... High-speed arithmetic unit.

Claims (2)

[Claims] 1. A vibrator for applying a force to a test object, a load detector for detecting a load applied by the vibrator, a displacement detector for detecting a displacement amount of the test object, and the load. An online earthquake that does not require numerical modeling of the restoring force characteristics of the DUT, which is equipped with a detector and a high-speed computing device that takes in the loads and displacements from the displacement detector online to calculate the vibration equation. In the response loading experimental device, using the load measured from the load detector as a restoring force, from the displacement amount measured from the displacement detector, the number of divisions to the next target point in the high speed computing device, If the increment of the actual displacement is small with respect to the increment of the force command value, the error is added to the next force command value, and the seismic wave is proportional to the real time. Reproducible as a time series waveform An on-line seismic response loading experiment device characterized by being enabled. 2. The step of applying displacement is fractionally multiplied,
2. The on-line seismic response loading test device according to claim 1, wherein the device is set so as to exceed the target value.