CN110702515A - Self-sensing FRP (fiber reinforced Plastic) rib embedded in piezoelectric ceramic sensor and use method thereof - Google Patents
Self-sensing FRP (fiber reinforced Plastic) rib embedded in piezoelectric ceramic sensor and use method thereof Download PDFInfo
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- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/07—Reinforcing elements of material other than metal, e.g. of glass, of plastics, or not exclusively made of metal
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Abstract
The invention discloses a self-sensing FRP rib embedded in a piezoelectric ceramic sensor and a use method thereof, wherein the self-sensing FRP rib comprises an FRP rib and a sensor component, the sensor component comprises a piezoelectric ceramic sensor and a BNC joint, and the piezoelectric ceramic sensor comprises a piezoelectric ceramic piece and a copper shell; the piezoelectric ceramic sensor is embedded into the notch of the FRP rib and is fixed through the packaging material layer; the self-sensing FRP rib is novel in structural design and can effectively realize real-time and on-line monitoring. The using method comprises the following steps: a. preparing a piezoelectric ceramic sensor; b. connecting the piezoelectric ceramic sensor with a BNC joint; c. selecting the FRP rib type and forming a notch; d. performing proportion test and proportion selection on the packaging material; e. embedding a piezoelectric ceramic sensor and filling a packaging material; f. monitoring; the use method can solve the problems of FRP rib abrasion and FRP rib and concrete interface monitoring, and can accurately evaluate the safety performance of the reinforced concrete structure.
Description
Technical Field
The invention relates to the technical field of civil engineering, in particular to a self-sensing FRP rib embedded with a piezoelectric ceramic sensor and a use method thereof.
Background
FRP reinforcements are widely used in the field of civil engineering, especially in reinforced concrete structures. It should be noted that, under the action of long-term natural environment, the FRP bar reinforced concrete structure is easy to wear and degrade in the performance of the interface between the FRP bar and the concrete, which results in the decrease of the ultimate bearing capacity of the reinforced concrete structure and the reduction of the normal service life.
Aiming at the situations, the abrasion of the FRP ribs and the damage of the interface of the FRP ribs and the concrete are effectively monitored in real time so as to evaluate the safety performance of the reinforced concrete structure and further avoid the occurrence of structural accidents, which has very important significance.
It should be noted that, the conventional sensor is difficult to monitor the wear of the FRP ribs and the interface damage between the FRP ribs and the concrete.
Disclosure of Invention
The invention aims to provide a self-sensing FRP rib embedded with a piezoelectric ceramic sensor, aiming at the defects of the prior art, the self-sensing FRP rib embedded with the piezoelectric ceramic sensor has novel structural design and can effectively realize real-time and online monitoring.
Another object of the present invention is to provide a method for using a self-sensing FRP bar embedded in a piezoelectric ceramic sensor, which can effectively solve the problems of FRP bar abrasion and FRP bar and concrete interface monitoring, and can accurately evaluate the safety performance of a reinforced concrete structure, so as to take corresponding remedial measures before a structural accident occurs, thereby preventing a catastrophic structural accident from occurring.
In order to achieve the above object, the present invention is achieved by the following technical solutions.
A self-sensing FRP rib embedded in a piezoelectric ceramic sensor comprises an FRP rib and a sensor component, wherein the sensor component comprises a piezoelectric ceramic sensor and a BNC joint, the piezoelectric ceramic sensor comprises a piezoelectric ceramic piece and a copper shell wrapped on the periphery of the piezoelectric ceramic piece, an anode terminal of the piezoelectric ceramic piece is connected with an anode lead, a cathode terminal of the piezoelectric ceramic piece is connected with a cathode lead, the anode lead and the cathode lead respectively penetrate through the copper shell and are respectively led out from the upper surface of the copper shell, and the anode lead and the cathode lead are respectively wrapped by an insulating outer wrapping layer; the positive terminal of the BNC connector is connected with the leading-out end of the positive wire, and the negative terminal of the BNC connector is connected with the leading-out end of the negative wire;
the surface of the FRP rib is provided with a notch formed by cutting with a high-speed laser cutting machine, a piezoelectric ceramic sensor of the sensor component is completely embedded into the notch of the FRP rib, and a packaging material layer for fixing the piezoelectric ceramic sensor is filled in the notch of the FRP rib; the packaging material adopted by the packaging material layer is formed by mixing resin and a curing agent, and the resin material adopted by the packaging material is the same as the matrix resin material of the FRP rib.
The FRP ribs are glass fiber reinforced ribs or basalt fiber reinforced ribs.
And the depth value of the notch of the FRP rib is less than one third of the diameter value of the FRP rib.
The surface of the FRP rib is provided with notches which are sequentially arranged along the length direction of the FRP rib at intervals, and the distance between every two adjacent notches is larger than 30 cm.
And the surface of the packaging material layer is flush with the surface of the FRP rib.
The thickness value of the piezoelectric ceramic piece is smaller than 1.2mm, and the thickness value of the copper shell is smaller than 0.02 mm.
A use method of a self-sensing FRP rib embedded in a piezoelectric ceramic sensor comprises the following steps:
a. preparing a piezoelectric ceramic sensor: selecting a piezoelectric ceramic piece and a copper shell with proper sizes, wrapping the copper shell on the periphery of the piezoelectric ceramic piece, connecting an anode terminal of the piezoelectric ceramic piece with an anode lead, connecting a cathode terminal of the piezoelectric ceramic piece with a cathode lead, respectively penetrating through the copper shell and respectively leading out from the upper surface of the copper shell, and respectively wrapping the anode lead and the cathode lead through an insulating outer wrapping layer;
b. connecting the piezoelectric ceramic sensor with a BNC joint: connecting the leading-out end of the positive wire of the piezoelectric ceramic sensor with the positive terminal of the BNC connector, and connecting the leading-out end of the negative wire of the piezoelectric ceramic sensor with the negative terminal of the BNC connector;
c. selecting an FRP rib type, and forming a notch on the surface of the selected FRP rib through a high-precision laser cutting machine;
d. selecting resin which is the same as the base resin material of the selected FRP rib as the resin material of the packaging material, mixing and stirring the resin material for the packaging material and the curing agent according to seven groups, wherein the ratio of the resin material for the packaging material to the curing agent in the first group is 4:1, the ratio of the resin material for the packaging material to the curing agent in the second group is 3:1, the ratio of the resin material for the packaging material to the curing agent in the third group is 2:1, the ratio of the resin material for the packaging material to the curing agent in the fourth group is 1:1, the ratio of the resin material for the packaging material to the curing agent in the fifth group is 1:2, the ratio of the resin material for the packaging material to the curing agent in the sixth group is 1:3, the ratio of the resin material for the packaging material to the curing agent in the seventh group is 1:4, curing the packaging material which is obtained by mixing and stirring the resin material and the curing agent in each group at the temperature of 22 ℃, and measuring the curing time of each group of encapsulating materials; after the curing time of the packaging materials of each group is determined, selecting the packaging materials with the curing time of 4-8 h as standby packaging materials;
e. completely embedding the piezoelectric ceramic sensor into the notch of the FRP rib, filling the selected standby packaging material into the notch of the FRP rib, forming a packaging material layer after the packaging material layer in the notch is solidified, fixing the piezoelectric ceramic sensor in the notch of the FRP rib by the packaging material layer, enabling the surface of the packaging material layer to be flush with the surface of the FRP rib, respectively extending a positive electrode wire and a negative electrode wire of the piezoelectric ceramic sensor to the outer side of the packaging material layer, and finishing the preparation of the self-sensing FRP rib;
f. monitoring the abrasion condition of the self-sensing FRP rib by adopting an impedance method: connecting a BNC joint of the piezoelectric ceramic sensor to an impedance tester, respectively obtaining resistance-frequency spectrograms at different moments, observing the resistance-frequency spectrograms, and analyzing the wear degree of the FRP ribs at different moments according to the number, the size and the offset of resonance peaks;
or monitoring the abrasion condition of the self-sensing FRP rib by adopting a fluctuation method: the self-sensing FRP rib is provided with two notches, a piezoelectric ceramic sensor fixed through a packaging material layer is embedded in each notch, a BNC connector of one piezoelectric ceramic sensor is connected to the transmitting end of an NIUSB-6366 data acquisition card, a BNC connector of the other piezoelectric ceramic sensor is connected to the receiving end of the NIUSB-6366 data acquisition card, and the NIUSB-6366 data acquisition card is connected with a computer; after the BNC connector, the NIUSB-6366 data acquisition card and the computer are connected, selecting the same signal excitation to act on the piezoelectric ceramic sensor connected with the NIUSB-6366 data acquisition card transmitting end, vibrating the piezoelectric ceramic sensor connected with the NIUSB-6366 data acquisition card transmitting end and generating stress waves, wherein the stress waves are propagated along the FRP ribs and received by the piezoelectric ceramic sensor connected with the NIUSB-6366 data acquisition card receiving end, the NIUSB-6366 data acquisition card transmits the received data to the computer at the receiving end, and the wear degree of the FRP ribs is judged by the computer according to the signal difference received at different times;
or monitoring the interface damage condition of the FRP rib and the self-compacting concrete by adopting a fluctuation method: preparing a bonding sliding test piece by utilizing a self-sensing FRP rib and self-compacting concrete, embedding an intelligent aggregate sensor at a position close to the FRP rib in the center of the test piece before preparing the bonding sliding test piece, and positioning a piezoelectric ceramic sensor embedded into a notch of the FRP rib at the outer side of the self-compacting concrete test piece, wherein a positive terminal of the intelligent aggregate sensor is connected with a positive terminal of a BNC joint through a lead, and a negative terminal of the intelligent aggregate sensor is connected with a negative terminal of the BNC joint through a lead; after the preparation of the bonding sliding test piece is completed, connecting a BNC joint of the piezoelectric ceramic sensor on the FRP rib to the transmitting end of an NIUSB-6366 data acquisition card, connecting a BNC joint of the intelligent aggregate sensor to the receiving end of the NIUSB-6366 data acquisition card, and connecting the NIUSB-6366 data acquisition card with a computer; after the BNC connector, the NIUSB-6366 data acquisition card and the computer are connected, the bonding sliding test piece is installed on a tension tester and is subjected to a drawing test through the tension tester, the same signal excitation is selected to act on the piezoelectric ceramic sensor on the FRP tendon in the drawing test process through the tension tester, the piezoelectric ceramic sensor vibrates and generates a stress wave, the stress wave is propagated in the FRP tendon, the interface between the FRP tendon and the self-compacting concrete, and the intelligent aggregate sensor receives the stress wave and judges the interface damage degree of the FRP tendon and the self-compacting concrete according to the received signal amplitude and frequency shift difference at different moments.
Wherein, in the process of monitoring the abrasion condition of the self-sensing FRP bar by adopting a fluctuation method, in order to quantify the damage degree of the interface of the FRP bar and the self-compacting concrete, a wavelet energy ratio index is provided and a symbol K is used foriRepresents;
the received signal S is decomposed into n +1 frequency bands by n-level wavelets, and the signal X of each frequency bandjExpressed as: xj＝[Xj,1,Xj,2,……,Xj,m](ii) a J represents a frequency band (j ═ 1,2, … …, n +1), and m represents the amount of sampled data;
energy meter for each frequency bandShown as follows:wherein i represents a time index;
according to the energy of each frequency band, the total energy of the signal received at the ith time can be expressed as:
in order to accurately reflect the damage degree of the FRP rib and the self-compacting concrete interface in the drawing test, the wavelet energy ratio index is defined as: ki＝Ei/E0(ii) a Wherein E isiRepresenting the total energy of the wavelet at different time indices, E0Representing the total wavelet energy under the healthy state with the load of 0 kN;
calculating wavelet energy ratios under different time indexes as quantization indexes, and drawing a bonding-sliding curve and a wavelet energy ratio index-sliding curve of the FRP ribs and the self-compacting concrete in the same graph; when the bonding stress reaches the peak value, the wavelet energy ratio index begins to rapidly degrade, which indicates that the bonding of the FRP tendon and the self-compacting concrete interface fails; the damage condition of the interface of the FRP rib and the self-compacting concrete can be quantified through the wavelet energy ratio index, the time of bonding degradation is locked, the condition of the internal interface of the structure is comprehensively mastered, and then a basis is provided for the macroscopic mechanical analysis of the structure.
The invention has the beneficial effects that: the invention relates to a self-sensing FRP (fiber reinforced Plastic) bar embedded in a piezoelectric ceramic sensor, which comprises an FRP bar and a sensor component, wherein the sensor component comprises a piezoelectric ceramic sensor and a BNC (bayonet nut connector), the piezoelectric ceramic sensor comprises a piezoelectric ceramic piece and a copper shell wrapped on the periphery of the piezoelectric ceramic piece, a positive terminal of the piezoelectric ceramic piece is connected with a positive wire, a negative terminal of the piezoelectric ceramic piece is connected with a negative wire, the positive wire and the negative wire respectively penetrate through the copper shell and are respectively led out from the upper surface of the copper shell, and the positive wire and the negative wire are respectively wrapped by an insulating outer wrapping layer; the positive terminal of the BNC connector is connected with the leading-out end of the positive wire, and the negative terminal of the BNC connector is connected with the leading-out end of the negative wire; the surface of the FRP rib is provided with a notch formed by cutting with a high-speed laser cutting machine, a piezoelectric ceramic sensor of the sensor component is completely embedded into the notch of the FRP rib, and a packaging material layer for fixing the piezoelectric ceramic sensor is filled in the notch of the FRP rib; the packaging material adopted by the packaging material layer is formed by mixing resin and a curing agent, and the resin material adopted by the packaging material is the same as the matrix resin material of the FRP rib. Through the structural design, the invention has the advantage of novel structural design and can effectively realize real-time and on-line monitoring.
The invention has the following beneficial effects: the invention relates to a use method of a self-sensing FRP rib embedded in a piezoelectric ceramic sensor, which comprises the following steps: a. preparing a piezoelectric ceramic sensor: selecting a piezoelectric ceramic piece and a copper shell with proper sizes, wrapping the copper shell on the periphery of the piezoelectric ceramic piece, connecting an anode terminal of the piezoelectric ceramic piece with an anode lead, connecting a cathode terminal of the piezoelectric ceramic piece with a cathode lead, respectively penetrating through the copper shell and respectively leading out from the upper surface of the copper shell, and respectively wrapping the anode lead and the cathode lead through an insulating outer wrapping layer; b. connecting the piezoelectric ceramic sensor with a BNC joint: connecting the leading-out end of the positive wire of the piezoelectric ceramic sensor with the positive terminal of the BNC connector, and connecting the leading-out end of the negative wire of the piezoelectric ceramic sensor with the negative terminal of the BNC connector; c. selecting an FRP rib type, and forming a notch on the surface of the selected FRP rib through a high-precision laser cutting machine; d. selecting resin which is the same as the matrix resin material of the selected FRP rib (1) as the resin material of the packaging material, mixing and stirring the resin material for the packaging material and the curing agent according to seven groups, wherein the ratio of the resin material for the packaging material to the curing agent in the first group is 4:1, the ratio of the resin material for the packaging material to the curing agent in the second group is 3:1, the ratio of the resin material for the packaging material to the curing agent in the third group is 2:1, the ratio of the resin material for the packaging material to the curing agent in the fourth group is 1:1, the ratio of the resin material for the packaging material to the curing agent in the fifth group is 1:2, the ratio of the resin material for the packaging material to the curing agent in the sixth group is 1:3, the ratio of the resin material for the packaging material to the curing agent in the seventh group is 1:4, curing the mixed and stirred packaging material of the resin material and the curing agent in each group at the temperature of 22 ℃, and measuring the curing time of each group of encapsulating materials; after the curing time of the packaging materials of each group is determined, selecting the packaging materials with the curing time of 4-8 h as standby packaging materials; e. completely embedding the piezoelectric ceramic sensor into the notch of the FRP rib, filling the selected standby packaging material into the notch of the FRP rib, forming a packaging material layer after the packaging material layer in the notch is solidified, fixing the piezoelectric ceramic sensor in the notch of the FRP rib by the packaging material layer, enabling the surface of the packaging material layer to be flush with the surface of the FRP rib, respectively extending a positive electrode wire and a negative electrode wire of the piezoelectric ceramic sensor to the outer side of the packaging material layer, and finishing the preparation of the self-sensing FRP rib; f. monitoring the abrasion condition of the self-sensing FRP rib by adopting an impedance method: connecting a BNC joint of the piezoelectric ceramic sensor to an impedance tester, respectively obtaining resistance-frequency spectrograms at different moments, observing the resistance-frequency spectrograms, and analyzing the wear degree of the FRP ribs at different moments according to the number, the size and the offset of resonance peaks; or monitoring the abrasion condition of the self-sensing FRP rib by adopting a fluctuation method: the self-sensing FRP rib is provided with two notches, a piezoelectric ceramic sensor fixed through a packaging material layer is embedded in each notch, a BNC connector of one piezoelectric ceramic sensor is connected to the transmitting end of an NIUSB-6366 data acquisition card, a BNC connector of the other piezoelectric ceramic sensor is connected to the receiving end of the NIUSB-6366 data acquisition card, and the NIUSB-6366 data acquisition card is connected with a computer; after the BNC connector, the NIUSB-6366 data acquisition card and the computer are connected, selecting the same signal excitation to act on the piezoelectric ceramic sensor connected with the NIUSB-6366 data acquisition card transmitting end, vibrating the piezoelectric ceramic sensor connected with the NIUSB-6366 data acquisition card transmitting end and generating stress waves, wherein the stress waves are propagated along the FRP ribs and received by the piezoelectric ceramic sensor connected with the NIUSB-6366 data acquisition card receiving end, the NIUSB-6366 data acquisition card transmits the received data to the computer at the receiving end, and the wear degree of the FRP ribs is judged by the computer according to the signal difference received at different times; or monitoring the interface damage condition of the FRP rib and the self-compacting concrete by adopting a fluctuation method: preparing a bonding sliding test piece by utilizing a self-sensing FRP rib and self-compacting concrete, embedding an intelligent aggregate sensor at a position close to the FRP rib in the center of the test piece before preparing the bonding sliding test piece, and positioning a piezoelectric ceramic sensor embedded into a notch of the FRP rib at the outer side of the self-compacting concrete test piece, wherein a positive terminal of the intelligent aggregate sensor is connected with a positive terminal of a BNC joint through a lead, and a negative terminal of the intelligent aggregate sensor is connected with a negative terminal of the BNC joint through a lead; after the preparation of the bonding sliding test piece is completed, connecting a BNC joint of the piezoelectric ceramic sensor on the FRP rib to the transmitting end of an NIUSB-6366 data acquisition card, connecting a BNC joint of the intelligent aggregate sensor to the receiving end of the NIUSB-6366 data acquisition card, and connecting the NIUSB-6366 data acquisition card with a computer; after the BNC connector, the NIUSB-6366 data acquisition card and the computer are connected, the bonding sliding test piece is installed on a tension tester and is subjected to a drawing test through the tension tester, the same signal excitation is selected to act on the piezoelectric ceramic sensor on the FRP tendon in the drawing test process through the tension tester, the piezoelectric ceramic sensor vibrates and generates a stress wave, the stress wave is propagated in the FRP tendon, the interface between the FRP tendon and the self-compacting concrete, and the intelligent aggregate sensor receives the stress wave and judges the interface damage degree of the FRP tendon and the self-compacting concrete according to the received signal amplitude and frequency shift difference at different moments. Through the steps, the use method of the self-sensing FRP rib embedded with the piezoelectric ceramic sensor can effectively solve the problems of FRP rib abrasion and monitoring of the interface between the FRP rib and concrete, and can accurately evaluate the safety performance of a reinforced concrete structure, so that corresponding remedial measures can be taken before structural accidents occur, and further catastrophic structural accidents are prevented.
Drawings
The invention will be further described with reference to the drawings to which, however, the embodiments shown in the drawings do not constitute any limitation.
Fig. 1 is a schematic structural view of the self-sensing FRP rib of the present invention.
Fig. 2 is a schematic structural diagram of a sensor assembly of the present invention.
FIG. 3 is a schematic diagram of monitoring the wear of the self-sensing FRP ribs by using an impedance method.
FIG. 4 is a schematic diagram of monitoring the wear of the self-sensing FRP ribs by a wave method.
FIG. 5 is a schematic diagram of monitoring the interface damage condition of the FRP rib and the self-compacting concrete by adopting a wave method.
FIG. 6 is a time domain signal diagram of monitoring the interface damage condition of the FRP rib and the self-compacting concrete by adopting a fluctuation method.
FIG. 7 is a frequency domain signal diagram of the case of monitoring the interface damage condition of the FRP rib and the self-compacting concrete by adopting a fluctuation method.
FIG. 8 is a schematic diagram of a bonding-slip curve and a wavelet energy ratio index-slip curve when an interface damage condition of an FRP rib and self-compacting concrete is monitored by adopting a fluctuation method.
Fig. 1 to 8 include:
1-FRP rib 11-notch
2-piezoelectric ceramic sensor 21-piezoelectric ceramic piece
22-copper shell 3-BNC joint
4-packaging material layer 5-impedance tester
6-NIUSB-6366 data acquisition card 7-computer
And 8, an intelligent aggregate sensor.
Detailed Description
The present invention will be described below with reference to specific embodiments.
As shown in fig. 1 and 3, a self-sensing FRP bar embedded in a piezoelectric ceramic sensor includes an FRP bar 1 and a sensor assembly, the sensor assembly includes a piezoelectric ceramic sensor 2 and a BNC connector 3, the piezoelectric ceramic sensor 2 includes a piezoelectric ceramic piece 21 and a copper shell 22 wrapped around the piezoelectric ceramic piece 21, an anode terminal of the piezoelectric ceramic piece 21 is connected with an anode wire, a cathode terminal of the piezoelectric ceramic piece 21 is connected with a cathode wire, the anode wire and the cathode wire respectively penetrate through the copper shell 22 and are respectively led out from the upper surface of the copper shell 22, and the anode wire and the cathode wire are respectively wrapped by an insulating outer wrapping layer; the positive terminal of the BNC connector 3 is connected with the leading-out end of the positive wire, and the negative terminal of the BNC connector 3 is connected with the leading-out end of the negative wire. It should be explained that, for the piezoelectric ceramic sensor 2 of the present invention, the piezoelectric ceramic sheet 21 is wrapped by the copper shell 22, and the copper shell 22 has a function of shielding noise, so that when the self-sensing FRP bar 1 of the present invention is used to monitor the wear condition or the interface damage condition between the FRP bar 1 and the self-compacting concrete, the copper shell 22 can shield external noise and improve the monitoring accuracy.
Further, a notch 11 formed by cutting with a high-speed laser cutting machine is formed in the surface of the FRP rib 1, the piezoelectric ceramic sensor 2 of the sensor assembly is completely embedded into the notch 11 of the FRP rib 1, and the packaging material layer 4 for fixing the piezoelectric ceramic sensor 2 is filled in the notch 11 of the FRP rib 1; the packaging material used by the packaging material layer 4 is formed by mixing resin and curing agent, and the resin material used by the packaging material is the same as the matrix resin material of the FRP rib 1. The surface of the packaging material layer 4 is flush with the surface of the FRP rib 1, the thickness value of the piezoelectric ceramic sheet 21 is smaller than 1.2mm, and the thickness value of the copper shell 22 is smaller than 0.02 mm.
Preferably, the FRP ribs 1 are glass fiber reinforced ribs or basalt fiber reinforced ribs.
It should be explained that the depth value of the notch 11 of the FRP rib 1 is less than one third of the diameter value of the FRP rib 1.
In addition, for the FRP rib 1 of the present invention, a plurality of notches 11 may be formed, specifically: the surface of the FRP rib 1 is provided with notches 11 which are sequentially arranged along the length direction of the FRP rib 1 at intervals, and the distance between every two adjacent notches 11 is larger than 30 cm.
In addition, the self-sensing FRP rib 1 can realize the monitoring of the abrasion condition of the FRP rib 1 by adopting the following method, in particular to a using method of the self-sensing FRP rib embedded with a piezoelectric ceramic sensor, which comprises the following steps:
a. preparing a piezoelectric ceramic sensor 2: selecting a PZT-5 type piezoelectric ceramic piece 21 with phi 12 multiplied by 1mm as the piezoelectric ceramic piece 21 of the invention, wherein the size of a copper shell 22 is slightly larger than that of the selected piezoelectric ceramic piece 21, wrapping the copper shell 22 at the periphery of the piezoelectric ceramic piece 21, the positive terminal of the piezoelectric ceramic piece 21 is connected with a positive lead, the negative terminal of the piezoelectric ceramic piece 21 is connected with a negative lead, the positive lead and the negative lead respectively penetrate through the copper shell 22 and are respectively led out from the upper surface of the copper shell 22, and the positive lead and the negative lead are respectively wrapped by an insulating outer wrapping layer;
b. connect piezoceramics sensor 2 and BNC joint 3: connecting the leading-out end of the positive wire of the piezoelectric ceramic sensor 2 with the positive terminal of the BNC connector 3, and connecting the leading-out end of the negative wire of the piezoelectric ceramic sensor 2 with the negative terminal of the BNC connector 3;
c. selecting the materials with the diameter value of 16mm, the matrix material of vinyl resin and the reinforced fiber as follows: forming a notch 11 on the surface of the selected FRP rib 1 by a high-precision laser cutting machine; the bottom surface of the notch 11 is 11.314 multiplied by 11.314mm in size, and the depth value is 2.343 mm;
d. packaging material proportioning test and proportion selection: selecting a vinyl resin as a resin material of the packaging material and selecting hexahydrophthalic anhydride as a curing agent of the packaging material, mixing and stirring the vinyl resin and the hexahydrophthalic anhydride according to seven groups, wherein the ratio of the vinyl resin to the hexahydrophthalic anhydride in the first group is 4:1, the ratio of the vinyl resin to the hexahydrophthalic anhydride in the second group is 3:1, the ratio of the vinyl resin to the hexahydrophthalic anhydride in the third group is 2:1, the ratio of the vinyl resin to the hexahydrophthalic anhydride in the fourth group is 1:1, the ratio of the vinyl resin to the hexahydrophthalic anhydride in the fifth group is 1:2, the ratio of the vinyl resin to the hexahydrophthalic anhydride in the sixth group is 1:3, the ratio of the vinyl resin to the hexahydrophthalic anhydride in the seventh group is 1:4, placing the packaging material obtained by mixing and stirring the vinyl resin and the hexahydrophthalic anhydride in each group in an environment at a temperature of 22 ℃ for curing, and measuring the curing time of each group of encapsulating materials; after the curing time of the packaging materials of each group is determined, selecting the packaging materials with the curing time of 4-8 h as standby packaging materials;
e. completely embedding the piezoelectric ceramic sensor 2 into the notch 11 of the FRP rib 1, then filling the selected standby packaging material into the notch 11 of the FRP rib 1, forming a packaging material layer 4 after the packaging material layer 4 in the notch 11 is cured, fixing the piezoelectric ceramic sensor 2 in the notch 11 of the FRP rib 1 by the packaging material layer 4, enabling the surface of the packaging material layer 4 to be flush with the surface of the FRP rib 1, respectively extending a positive electrode lead and a negative electrode lead of the piezoelectric ceramic sensor 2 to the outer side of the packaging material layer 4, and finishing the preparation of the self-sensing FRP rib 1;
f. monitoring the abrasion condition of the self-sensing FRP rib 1 by adopting an impedance method: connecting the BNC connector 3 of the piezoelectric ceramic sensor 2 to an impedance tester 5, respectively obtaining resistance-frequency spectrograms at different moments, observing the resistance-frequency spectrograms, and analyzing the wear degree of the FRP ribs 1 at different moments according to the number, the size and the offset of resonance peaks (shown in figure 3);
or monitoring the abrasion condition of the self-sensing FRP rib 1 by adopting a fluctuation method: the self-sensing FRP rib 1 is provided with two notches 11, a piezoelectric ceramic sensor 2 fixed through a packaging material layer 4 is embedded in each notch 11, a BNC connector 3 of one piezoelectric ceramic sensor 2 is connected to the transmitting end of an NIUSB-6366 data acquisition card 6, a BNC connector 3 of the other piezoelectric ceramic sensor 2 is connected to the receiving end of the NIUSB-6366 data acquisition card 6, and the NIUSB-6366 data acquisition card 6 is connected with a computer 7; after the BNC connector 3, the NIUSB-6366 data acquisition card 6 and the computer 7 are connected, the same signal excitation is selected to act on the piezoelectric ceramic sensor 2 connected with the transmitting end of the NIUSB-6366 data acquisition card 6, at the moment, the piezoelectric ceramic sensor 2 connected with the transmitting end of the NIUSB-6366 data acquisition card 6 vibrates and generates stress waves, the stress waves are transmitted along the FRP tendon 1 and received by the piezoelectric ceramic sensor 2 connected with the receiving end of the NIUSB-6366 data acquisition card 6, the NIUSB-6366 data acquisition card 6 transmits the received data to the computer 7 by the receiving end, and the abrasion degree of the tendon 1 is judged by the computer 7 according to the signal difference received at different FRP scales (as shown in FIG. 4).
It should be further noted that the self-sensing FRP bar 1 of the present invention can implement monitoring of the interface damage condition between the FRP bar 1 and the self-compacting concrete by the following method, and specifically, the use method of the self-sensing FRP bar embedded in the piezoelectric ceramic sensor includes the following steps:
a. preparing a piezoelectric ceramic sensor 2: selecting a PZT-5 type piezoelectric ceramic piece 21 with the diameter of 8 multiplied by 0.8mm as the piezoelectric ceramic piece 21 of the invention, wherein the size of a copper shell 22 is slightly larger than the size of the selected piezoelectric ceramic piece 21, the copper shell 22 is wrapped on the periphery of the piezoelectric ceramic piece 21, an anode terminal of the piezoelectric ceramic piece 21 is connected with an anode lead, a cathode terminal of the piezoelectric ceramic piece 21 is connected with a cathode lead, the anode lead and the cathode lead respectively penetrate through the copper shell 22 and are respectively led out from the upper surface of the copper shell 22, and the anode lead and the cathode lead are respectively wrapped by an insulating outer wrapping layer;
b. connect piezoceramics sensor 2 and BNC joint 3: connecting the leading-out end of the positive wire of the piezoelectric ceramic sensor 2 with the positive terminal of the BNC connector 3, and connecting the leading-out end of the negative wire of the piezoelectric ceramic sensor 2 with the negative terminal of the BNC connector 3;
c. selecting an FRP rib 1 with the diameter value of 12mm, the matrix material of epoxy resin and the reinforcing fiber of glass fiber, and forming a notch 11 on the surface of the selected FRP rib 1 through a high-precision laser cutting machine; the bottom surface of the notch 11 is 8.485 multiplied by 8.485mm, and the depth value is 1.757 mm;
d. packaging material proportioning test and proportion selection: selecting epoxy resin as resin material of the packaging material and 651 low molecular polyamide as curing agent of the packaging material, mixing and stirring the epoxy resin and 651 low molecular polyamide according to seven groups, wherein the ratio of the epoxy resin to the 651 low molecular polyamide in the first group is 4:1, the ratio of the epoxy resin to the 651 low molecular polyamide in the second group is 3:1, the ratio of the epoxy resin to the 651 low molecular polyamide in the third group is 2:1, the ratio of the epoxy resin to the 651 low molecular polyamide in the fourth group is 1:1, the ratio of the epoxy resin to the 651 low molecular polyamide in the fifth group is 1:2, the ratio of the epoxy resin to the 651 low molecular polyamide in the sixth group is 1:3, the ratio of the epoxy resin to the 651 low molecular polyamide in the seventh group is 1:4, placing the packaging material of each group after mixing and stirring the epoxy resin and the 651 low molecular polyamide in an environment with the temperature of 22 ℃ for curing, and measuring the curing time of each group of encapsulating materials; after the curing time of the packaging materials of each group is determined, selecting the packaging materials with the curing time of 4-8 h as standby packaging materials;
e. completely embedding the piezoelectric ceramic sensor 2 into the notch 11 of the FRP rib 1, then filling the selected standby packaging material into the notch 11 of the FRP rib 1, forming a packaging material layer 4 after the packaging material layer 4 in the notch 11 is cured, fixing the piezoelectric ceramic sensor 2 in the notch 11 of the FRP rib 1 by the packaging material layer 4, enabling the surface of the packaging material layer 4 to be flush with the surface of the FRP rib 1, respectively extending a positive electrode lead and a negative electrode lead of the piezoelectric ceramic sensor 2 to the outer side of the packaging material layer 4, and finishing the preparation of the self-sensing FRP rib 1;
f. monitoring the interface damage condition of the FRP rib 1 and the self-compacting concrete by adopting a fluctuation method: preparing a bonding and sliding test piece by using a self-sensing FRP rib 1 and self-compacting concrete, embedding an intelligent aggregate sensor 8 at a position close to the FRP rib 1 in the center of the test piece before preparing the bonding and sliding test piece, and positioning a piezoelectric ceramic sensor 2 embedded into a notch 11 of the FRP rib 1 at the outer side of the self-compacting concrete test piece, wherein a positive terminal of the intelligent aggregate sensor 8 is connected with a positive terminal of a BNC connector 3 through a lead, and a negative terminal of the intelligent aggregate sensor 8 is connected with a negative terminal of the BNC connector 3 through a lead; after the preparation of the bonding sliding test piece is completed, connecting the BNC connector 3 of the piezoelectric ceramic sensor 2 on the FRP rib 1 to the transmitting end of the NIUSB-6366 data acquisition card 6, connecting the BNC connector 3 of the intelligent aggregate sensor 8 to the receiving end of the NIUSB-6366 data acquisition card 6, and connecting the NIUSB-6366 data acquisition card 6 with the computer 7; after the BNC connector 3, the NIUSB-6366 data acquisition card 6 and the computer 7 are connected, the bonding sliding test piece is installed on a tensile testing machine and is subjected to a drawing test through the tensile testing machine, the same signal excitation is selected to act on the piezoelectric ceramic sensor 2 on the FRP tendon 1 in the drawing test process through the tensile testing machine, the piezoelectric ceramic sensor 2 vibrates and generates a stress wave which is transmitted in the interfaces of the FRP tendon 1, the FRP tendon 1 and the self-compacting concrete, and the intelligent aggregate sensor 8 receives the stress wave and judges the damage degree of the interfaces of the FRP tendon 1 and the self-compacting concrete according to the received signal amplitude and frequency shift difference at different moments as shown in FIG. 5; wherein, the time domain signal diagram received at different time is as shown in fig. 6 and the frequency domain signal diagram is as shown in fig. 7;
it is explained that in the process of monitoring the abrasion condition of the self-sensing FRP bar 1 by adopting the fluctuation method, in order to quantify the damage degree of the interface between the FRP bar 1 and the self-compacting concrete, a wavelet energy ratio index is provided and a symbol K is used for the wavelet energy ratio indexiRepresents;
the received signal S is decomposed into n +1 frequency bands by n-level wavelets, and the signal X of each frequency bandjExpressed as: xj＝[Xj,1,Xj,2,……,Xj,m](ii) a J represents a frequency band j which is 1,2, … …, n +1, and m represents the sampling data quantity;
the energy per frequency band is represented as:
wherein i represents a time index;
according to the energy of each frequency band, the total energy of the signal received at the ith time can be expressed as:
in order to accurately reflect the damage degree of the FRP rib 1 and the self-compacting concrete interface in the drawing test, the wavelet energy ratio index is defined as: ki＝Ei/E0(ii) a Wherein E isiRepresenting the total energy of the wavelet at different time indices, E0Representing the total wavelet energy under the healthy state with the load of 0 kN;
calculating wavelet energy ratio under different time indexes as quantization indexes, and drawing a bonding-sliding curve and a wavelet energy ratio index-sliding curve (shown in figure 8) of the FRP rib 1 and the self-compacting concrete in the same graph; when the bonding stress reaches the peak value, the wavelet energy ratio index begins to rapidly degrade, which indicates that the bonding between the FRP rib 1 and the self-compacting concrete interface fails; the damage condition of the FRP rib 1 and the self-compacting concrete interface can be quantified through the wavelet energy ratio index, the time of bonding degradation is locked, the condition of the structure internal interface is comprehensively mastered, and then a basis is provided for the macroscopic mechanical analysis of the structure.
From the above situation, the self-sensing FRP rib embedded in the piezoelectric ceramic sensor has the advantage of novel structural design, and can effectively realize real-time and online monitoring. In addition, the use method of the self-sensing FRP rib embedded with the piezoelectric ceramic sensor can effectively solve the problems of abrasion of the FRP rib 1 and monitoring of the interface between the FRP rib 1 and concrete, and can accurately evaluate the safety performance of the reinforced concrete structure, so that corresponding remedial measures can be taken before structural accidents occur, and further catastrophic structural accidents are prevented.
The above description is only a preferred embodiment of the present invention, and for those skilled in the art, the present invention should not be limited by the description of the present invention, which should be interpreted as a limitation.
Claims (8)
1. The utility model provides a self-perception FRP muscle of embedding piezoceramics sensor which characterized in that: the sensor comprises an FRP (fiber reinforced plastic) rib (1) and a sensor component, wherein the sensor component comprises a piezoelectric ceramic sensor (2) and a BNC connector (3), the piezoelectric ceramic sensor (2) comprises a piezoelectric ceramic piece (21) and a copper shell (22) wrapped on the periphery of the piezoelectric ceramic piece (21), an anode terminal of the piezoelectric ceramic piece (21) is connected with an anode wire, a cathode terminal of the piezoelectric ceramic piece (21) is connected with a cathode wire, the anode wire and the cathode wire respectively penetrate through the copper shell (22) and are respectively led out from the upper surface of the copper shell (22), and the anode wire and the cathode wire are respectively wrapped by an insulating outer wrapping layer; the positive terminal of the BNC connector (3) is connected with the leading-out end of the positive wire, and the negative terminal of the BNC connector (3) is connected with the leading-out end of the negative wire;
the surface of the FRP rib (1) is provided with a notch (11) formed by cutting through a high-speed laser cutting machine, a piezoelectric ceramic sensor (2) of a sensor assembly is completely embedded into the notch (11) of the FRP rib (1), and a packaging material layer (4) for fixing the piezoelectric ceramic sensor (2) is filled in the notch (11) of the FRP rib (1); the packaging material adopted by the packaging material layer (4) is formed by mixing resin and a curing agent, and the resin material adopted by the packaging material is the same as the matrix resin material of the FRP rib (1).
2. The self-sensing FRP rib embedded in a piezoelectric ceramic sensor as claimed in claim 1, wherein: the FRP ribs (1) are glass fiber reinforced ribs or basalt fiber reinforced ribs.
3. The self-sensing FRP rib embedded in a piezoelectric ceramic sensor as claimed in claim 1, wherein: the depth value of the notch (11) of the FRP rib (1) is less than one third of the diameter value of the FRP rib (1).
4. The self-sensing FRP rib embedded in a piezoelectric ceramic sensor as claimed in claim 1, wherein: the surface of the FRP rib (1) is provided with notches (11) which are sequentially arranged along the length direction of the FRP rib (1) at intervals, and the distance between every two adjacent notches (11) is larger than 30 cm.
5. The self-sensing FRP rib embedded in a piezoelectric ceramic sensor as claimed in claim 1, wherein: the surface of the packaging material layer (4) is flush with the surface of the FRP rib (1).
6. The self-sensing FRP rib embedded in a piezoelectric ceramic sensor as claimed in claim 1, wherein: the thickness value of the piezoelectric ceramic piece (21) is smaller than 1.2mm, and the thickness value of the copper shell (22) is smaller than 0.02 mm.
7. A use method of a self-sensing FRP rib embedded in a piezoelectric ceramic sensor is characterized by comprising the following steps:
a. preparing a piezoelectric ceramic sensor (2): selecting a piezoelectric ceramic piece (21) and a copper shell (22) with proper sizes, wrapping the copper shell (22) on the periphery of the piezoelectric ceramic piece (21), connecting a positive terminal of the piezoelectric ceramic piece (21) with a positive wire, connecting a negative terminal of the piezoelectric ceramic piece (21) with a negative wire, respectively penetrating the copper shell (22) and respectively leading out from the upper surface of the copper shell (22), and wrapping the positive wire and the negative wire respectively through an insulating outer wrapping layer;
b. connecting the piezoelectric ceramic sensor (2) with the BNC connector (3): connecting the leading-out end of the positive wire of the piezoelectric ceramic sensor (2) with the positive terminal of the BNC connector (3), and connecting the leading-out end of the negative wire of the piezoelectric ceramic sensor (2) with the negative terminal of the BNC connector (3);
c. selecting the type of the FRP rib (1), and forming a notch (11) on the surface of the selected FRP rib (1) through a high-precision laser cutting machine;
d. packaging material proportioning test and proportion selection: selecting resin which is the same as the matrix resin material of the selected FRP rib (1) as the resin material of the packaging material, mixing and stirring the resin material for the packaging material and the curing agent according to seven groups, wherein the ratio of the resin material for the packaging material to the curing agent in the first group is 4:1, the ratio of the resin material for the packaging material to the curing agent in the second group is 3:1, the ratio of the resin material for the packaging material to the curing agent in the third group is 2:1, the ratio of the resin material for the packaging material to the curing agent in the fourth group is 1:1, the ratio of the resin material for the packaging material to the curing agent in the fifth group is 1:2, the ratio of the resin material for the packaging material to the curing agent in the sixth group is 1:3, the ratio of the resin material for the packaging material to the curing agent in the seventh group is 1:4, curing the mixed and stirred packaging material of the resin material and the curing agent in each group at the temperature of 22 ℃, and measuring the curing time of each group of encapsulating materials; after the curing time of the packaging materials of each group is determined, selecting the packaging materials with the curing time of 4-8 h as standby packaging materials;
e. completely embedding the piezoelectric ceramic sensor (2) into a notch (11) of the FRP rib (1), then filling the selected standby packaging material into the notch (11) of the FRP rib (1), forming a packaging material layer (4) after the packaging material layer (4) in the notch (11) is cured, fixing the piezoelectric ceramic sensor (2) in the notch (11) of the FRP rib (1) by the packaging material layer (4), enabling the surface of the packaging material layer (4) to be flush with the surface of the FRP rib (1), respectively extending a positive electrode wire and a negative electrode wire of the piezoelectric ceramic sensor (2) to the outer side of the packaging material layer (4), and finishing the preparation of the self-sensing FRP rib (1);
f. monitoring the abrasion condition of the self-sensing FRP rib (1) by adopting an impedance method: connecting a BNC joint (3) of the piezoelectric ceramic sensor (2) to an impedance tester (5), respectively obtaining resistance-frequency spectrograms at different moments, observing the resistance-frequency spectrograms, and analyzing the wear degree of the FRP ribs (1) at different moments according to the number, the size and the offset of resonance peaks;
or monitoring the abrasion condition of the self-sensing FRP rib (1) by adopting a fluctuation method: the self-sensing FRP rib (1) is provided with two notches (11), a piezoelectric ceramic sensor (2) fixed through a packaging material layer (4) is embedded into each notch (11), a BNC connector (3) of one piezoelectric ceramic sensor (2) is connected to the transmitting end of an NIUSB-6366 data acquisition card (6), a BNC connector (3) of the other piezoelectric ceramic sensor (2) is connected to the receiving end of the NIUSB-6366 data acquisition card (6), and the NIUSB-6366 data acquisition card (6) is connected with a computer (7); after the BNC connector (3), the NIUSB-6366 data acquisition card (6) and the computer (7) are connected, the same signal excitation is selected to act on the piezoelectric ceramic sensor (2) connected with the transmitting end of the NIUSB-6366 data acquisition card (6), at the moment, the piezoelectric ceramic sensor (2) connected with the transmitting end of the NIUSB-6366 data acquisition card (6) vibrates and generates stress waves, the stress waves are transmitted along the FRP tendon (1) and received by the piezoelectric ceramic sensor (2) connected with the receiving end of the NIUSB-6366 data acquisition card (6), the NIUSB-6366 data acquisition card (6) sends the received data to the computer (7) by the receiving end, and the wear degree of the FRP tendon (1) is judged by the computer (7) according to the signal difference received at different times;
or monitoring the interface damage condition of the FRP rib (1) and the self-compacting concrete by adopting a fluctuation method: preparing a bonding sliding test piece by utilizing a self-sensing FRP rib (1) and self-compacting concrete, embedding an intelligent aggregate sensor (8) at a position close to the FRP rib (1) in the center of the test piece before preparing the bonding sliding test piece, wherein a piezoelectric ceramic sensor (2) embedded into a notch (11) of the FRP rib (1) is positioned at the outer side of the self-compacting concrete test piece, a positive terminal of the intelligent aggregate sensor (8) is connected with a positive terminal of a BNC joint (3) through a wire, and a negative terminal of the intelligent aggregate sensor (8) is connected with a negative terminal of the BNC joint (3) through a wire; after the preparation of the bonding sliding test piece is completed, connecting a BNC connector (3) of a piezoelectric ceramic sensor (2) on the FRP rib (1) to the transmitting end of an NIUSB-6366 data acquisition card (6), connecting a BNC connector (3) of an intelligent aggregate sensor (8) to the receiving end of the NIUSB-6366 data acquisition card (6), and connecting the NIUSB-6366 data acquisition card (6) with a computer (7); waiting for BNC joint (3), NIUSB-6366 data acquisition card (6), after computer (7) connection, will bond the test piece that slides and install to tensile testing machine and draw the experiment through tensile testing machine, in drawing the test process through tensile testing machine, select the same signal excitation to act on piezoceramics sensor (2) on FRP muscle (1), piezoceramics sensor (2) vibrations and produce the stress wave this moment, the stress wave propagates in FRP muscle (1), FRP muscle (1) and self-compaction concrete interface and self-compaction concrete, intelligent aggregate sensor (8) receives the stress wave, and receive signal amplitude under the different time, frequency shift difference judges FRP muscle (1) and self-compaction concrete interface damage degree.
8. The use method of the self-sensing FRP rib embedded in the piezoelectric ceramic sensor as claimed in claim 7, wherein: in the process of monitoring the abrasion condition of the self-sensing FRP bar (1) by adopting a fluctuation method, in order to quantify the damage degree of the interface between the FRP bar (1) and the self-compacting concrete, a wavelet energy ratio index is provided and a symbol K is usediRepresents;
the received signal S is decomposed into n +1 frequency bands by n-level wavelets, and the signal X of each frequency bandjExpressed as: xj＝[Xj,1,Xj,2,……,Xj,m](ii) a J represents a frequency band (j ═ 1,2, … …, n +1), and m represents the amount of sampled data;
the energy per frequency band is represented as:
wherein i represents a time index;
according to the energy of each frequency band, the total energy of the signal received at the ith time can be expressed as:
in order to accurately reflect the damage degree of the FRP rib (1) and the self-compacting concrete interface in the drawing test, the wavelet energy ratio index is defined as: ki＝Ei/E0(ii) a Wherein E isiRepresenting the total energy of the wavelet at different time indices, E0Representing the total wavelet energy under the healthy state with the load of 0 kN;
calculating wavelet energy ratios under different time indexes as quantization indexes, and drawing a bonding-sliding curve and a wavelet energy ratio index-sliding curve of the FRP rib (1) and the self-compacting concrete in the same graph; when the bonding stress reaches the peak value, the wavelet energy ratio index begins to be rapidly degraded, which indicates that the bonding of the FRP tendon (1) and the self-compacting concrete interface fails; the damage condition of the FRP rib (1) and the self-compacting concrete interface can be quantified through the wavelet energy ratio index, the time of bonding degradation is locked, the condition of the structure internal interface is comprehensively mastered, and then a basis is provided for the macroscopic mechanical analysis of the structure.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111521642A (en) * | 2020-02-24 | 2020-08-11 | 重庆大学 | Device and method for detecting fracture of prestressed steel wire of Prestressed Concrete Cylinder Pipe (PCCP) based on piezoelectric sensing technology |
| CN111721630A (en) * | 2020-07-08 | 2020-09-29 | 中建四局第三建设有限公司 | Piezoelectric solidified soil for in-situ detection of sludge solidification and preparation method thereof |
| CN114609193A (en) * | 2022-04-01 | 2022-06-10 | 哈尔滨工业大学（深圳） | Epoxy resin mechanical property monitoring sensor, sensing device and method |
| CN117368446A (en) * | 2023-10-11 | 2024-01-09 | 东莞理工学院 | Cement concrete pavement crack monitoring method and system based on piezoelectric ceramic sensor |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012229982A (en) * | 2011-04-26 | 2012-11-22 | Toyo Constr Co Ltd | Method and apparatus for health monitoring of concrete structure |
| CN103808436A (en) * | 2014-02-26 | 2014-05-21 | 长沙理工大学 | FRP rib interface shear stress monitoring device and method based on thickness shear deformation PZT |
| CN103883076A (en) * | 2014-02-26 | 2014-06-25 | 长沙理工大学 | Intelligent hybrid composite FRP prestressed tendon based on piezoelectric ceramics and preparation method thereof |
| CN210982036U (en) * | 2019-10-18 | 2020-07-10 | 东莞理工学院 | Self-sensing FRP (fiber reinforced Plastic) rib embedded in piezoelectric ceramic sensor |
-
2019
- 2019-10-18 CN CN201910991009.6A patent/CN110702515B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012229982A (en) * | 2011-04-26 | 2012-11-22 | Toyo Constr Co Ltd | Method and apparatus for health monitoring of concrete structure |
| CN103808436A (en) * | 2014-02-26 | 2014-05-21 | 长沙理工大学 | FRP rib interface shear stress monitoring device and method based on thickness shear deformation PZT |
| CN103883076A (en) * | 2014-02-26 | 2014-06-25 | 长沙理工大学 | Intelligent hybrid composite FRP prestressed tendon based on piezoelectric ceramics and preparation method thereof |
| CN210982036U (en) * | 2019-10-18 | 2020-07-10 | 东莞理工学院 | Self-sensing FRP (fiber reinforced Plastic) rib embedded in piezoelectric ceramic sensor |
Non-Patent Citations (1)
| Title |
|---|
| 周玲珠 等: "基于时间反演法的纤维增强复材/钢筋增强混凝土梁损伤监测研究", 《工业建筑》, vol. 49, no. 9, 30 September 2019 (2019-09-30), pages 196 - 201 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111521642A (en) * | 2020-02-24 | 2020-08-11 | 重庆大学 | Device and method for detecting fracture of prestressed steel wire of Prestressed Concrete Cylinder Pipe (PCCP) based on piezoelectric sensing technology |
| CN111721630A (en) * | 2020-07-08 | 2020-09-29 | 中建四局第三建设有限公司 | Piezoelectric solidified soil for in-situ detection of sludge solidification and preparation method thereof |
| CN111721630B (en) * | 2020-07-08 | 2022-07-08 | 中建四局第三建设有限公司 | Piezoelectric solidified soil for in-situ detection of sludge solidification and preparation method thereof |
| CN114609193A (en) * | 2022-04-01 | 2022-06-10 | 哈尔滨工业大学（深圳） | Epoxy resin mechanical property monitoring sensor, sensing device and method |
| CN114609193B (en) * | 2022-04-01 | 2024-07-09 | 哈尔滨工业大学（深圳） | Epoxy resin mechanical property monitoring sensor, sensing device and method |
| CN117368446A (en) * | 2023-10-11 | 2024-01-09 | 东莞理工学院 | Cement concrete pavement crack monitoring method and system based on piezoelectric ceramic sensor |
| CN117368446B (en) * | 2023-10-11 | 2024-05-24 | 东莞理工学院 | Cement concrete pavement crack monitoring method and system based on piezoelectric ceramic sensor |
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