CN115825228A - Quantitative calibration method and test system for engineering structure interface damage detection - Google Patents

Abstract

The invention discloses a quantitative calibration method and a test system for engineering structure interface damage detection, wherein the method comprises the following steps: knocking the surface to be detected of the combined structure by a power hammer to generate a repetitive excitation signal; arranging a sensor group which comprises a piezoelectric ceramic piece, a high-frequency accelerometer, an ultrasonic sensor, a low-frequency microphone, a high-frequency microphone and a laser vibration meter and is used for carrying out contact type and non-contact type measurement on the generated stress wave; the data acquisition and analysis equipment excavates the mapping relation between the characteristic indexes of the test signals of different sensors and the damage size based on a machine learning method, and calibrates the test ranges of different sensors; the laser vibration meter is used for non-contact measurement on one hand, and is used for verifying and calibrating test data and test ranges of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone and the high-frequency microphone on the other hand. The invention can obviously improve the precision and the application range of the interface damage test.

Description

Quantitative calibration method and test system for engineering structure interface damage detection

Technical Field

The invention relates to the technical field of engineering structure damage detection, in particular to a quantitative calibration method and a test system for engineering structure interface damage detection.

Background

Steel-concrete composite structures, steel plate reinforced concrete structures, FRP reinforced concrete structures, are widely used in the reinforcement and repair of large civil engineering structures. The structure has the common problem of bonding interfaces among different materials, and is a foundation for ensuring the common stress of steel and concrete, FRP and concrete. However, effective non-destructive testing techniques for interfacial debonding, and slipping are still lacking. In addition, the existing testing technology has the problem of inconsistent precision. The precision of the equipment and the sensor adopted by the same testing technology is obviously different, the physical quantity of the test is different between different testing technologies, such as a microphone is based on acoustics, an accelerometer is based on vibration, a piezoelectric ceramic PZT is also an unpackaged wide frequency domain sensing element, and an ultrasonic sensor is based on high frequency stress wave (which is not sensitive to low frequency vibration). Due to the reasons, the interface damage detection in the existing engineering structure has obvious technical bottleneck, and an efficient quantitative test method and accurate contrast data support are lacked, so that the defect detection rate is low.

The existing interface damage testing method is generally developed based on damage testing of concrete structures and steel structures, such as an impact echo method, an impact sound vibration method, an impact response method, an ultrasonic wave pair testing method, an ultrasonic wave CT (computed tomography) method and the like. The signal analysis of the method assumes that the material composition of the component to be measured is a material, and assumes that the component to be measured is a homogeneous material in the theoretical analysis.

Different from concrete structures and steel structures, steel and concrete form a combined structure, FRP (carbon fiber) cloth/plate and concrete form a composite structure, and the combined structure and the composite structure are both made of two different materials. In addition, the thickness of the steel plate and FRP cloth/plate is very small compared to concrete. Because the elastic modulus, the density and the Poisson ratio of different materials are different remarkably, the difference between the vibration characteristic and the propagation speed of the stress wave is large, so that the inconsistent vibration deformation and the interface reflection of the stress wave caused by impedance mismatching can be generated at the interface. Therefore, the existing testing method developed based on single material hypothesis is difficult to meet the requirement of accurate testing of interface damage in the engineering structure.

It is based on the parameter difference of different materials, such as thermal conductivity, etc., the temperature test and the ray method can be used for testing the FRP interface damage. However, the steel plate is arranged at the outermost side of the combined structure, and the steel material has high thermal conductivity, so that the steel plate is difficult to be used for a damage test of the steel-concrete combined structure. The electromagnetic wave method is not suitable for a steel-concrete composite structure due to the shielding effect of the steel plate.

The solutions for the comparative compromises in the existing studies are: based on a traditional impact echo method, an impact sound vibration method and an impact response method, relevant data are collected by ultrasonic waves to test equipment, and then signal attenuation characteristics, amplitude and frequency difference are compared to qualitatively judge whether interface damage exists or not. Different scholars and detection organizations generally only carry out the test of one method, which directly causes the results obtained by different detection personnel to be inconsistent. The single testing method can only be used for detecting the defects of the interface with a larger area, has poor detection effect on the defects with smaller size, and is easy to misjudge because the damage evaluation in the nondestructive testing depends on the engineering experience of the testing personnel.

Therefore, the core problems faced by the current interface damage test mainly include: 1. based on the traditional impact echo method, the impact sound vibration method, the impact response method, the ultrasonic wave pair measuring method and the ultrasonic wave CT method, the sensor of commercial equipment can not be directly used as a sensing element, because the sensor has larger size and larger test error; 2. the sampling precision and the range difference of acquisition systems of different equipment are obvious, the operability of signal comparison is seriously hindered, and due to the reasons of inconsistent models of sensors configured by the equipment, unmatched interfaces, different sensing physical quantities and the like, synchronous acquisition of various signals cannot be realized; 3. lack of systematic mapping test methods and embodiments, inability to quantify test accuracy differences between different methods; 4. the mapping relation between the characteristic indexes of the test signals and the damage size is lack of high efficiency and accuracy, and the dependency of damage evaluation on the experience of the test personnel is obvious.

In addition, the conventional microphone adopted in the existing impact sound vibration test collects sound signals, and the low-frequency accelerometer is adopted to collect vibration signals of the steel plate at the defect position. When the size of the interface defect is small and the thickness of the steel plate is large, the frequency of sound and vibration signals exceeds 20kHZ, the existing impact sound vibration test sensing range is limited, and the method is difficult to apply. Moreover, the existing single test scheme is actually measured in indoor research, so that the calibrated working conditions are few, the signal difference caused by interface damage of the sensor and the excitation end is difficult to comprehensively express, and the inaccurate current situation of the interface damage test is further aggravated.

Disclosure of Invention

Aiming at the defects of low test accuracy and lack of a mapping test method presented by the engineering structure interface damage test based on a single test method at present, the invention aims to provide a quantitative calibration method and a test system for the engineering structure interface damage test, and aims to improve the precision of the interface damage test through an efficient test technology and a quantitative comparison scheme so as to realize accurate identification of the interface damage size. The invention solves the limitation of the conventional low-frequency microphone test (when the interface size is too small or the thickness of the steel plate is too large, the frequency of the sound signal is more than 20kHz and exceeds the sensing range of the conventional microphone) through the combination of the high-frequency microphone and the low-frequency microphone. In addition, the comprehensive test system and the method can be widely applied to interface damage identification in steel-concrete interfaces, FRP-concrete interfaces and prefabricated concrete structures.

To solve the above technical problem, an embodiment of the present invention provides the following solutions:

on one hand, the quantitative calibration method for detecting the damage of the engineering structure interface comprises the following steps:

knocking the surface to be detected of the combined structure by using an automatic power hammer as an excitation device to generate a repetitive excitation signal;

arranging a sensor group; the sensor group comprises a piezoelectric ceramic piece, a high-frequency accelerometer, an ultrasonic sensor, a low-frequency microphone, a high-frequency microphone and a laser vibration meter;

the piezoelectric ceramic piece, the high-frequency accelerometer and the ultrasonic sensor are arranged on the surface to be detected of the combined structure and used for carrying out contact measurement on the generated stress wave; the low-frequency microphone, the high-frequency microphone and the laser vibration meter are arranged in front of the surface to be detected of the combined structure and used for carrying out non-contact measurement on the generated stress;

collecting test signals of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone, the high-frequency microphone and the laser vibration meter by using data collecting and analyzing equipment;

the data acquisition and analysis equipment excavates the mapping relation between the characteristic indexes of the test signals of different sensors and the damage size based on a machine learning method, and calibrates the test ranges of different sensors;

the laser vibration meter is used for non-contact measurement on one hand, and is used for verifying test data of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone and the high-frequency microphone on the other hand, and calibrating test ranges of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone and the high-frequency microphone on the other hand.

Preferably, the piezoelectric ceramic piece and/or the ultrasonic sensor is matched with the automatic hammer for performing impact-echo test;

the high-frequency accelerometer and/or the laser vibration meter are matched with the automatic hammer for performing impact-response test;

and the low-frequency microphone and/or the high-frequency microphone are/is matched with the automatic hammer for carrying out impact-sound vibration test.

Preferably, according to the difference of vibration modes of the position with good interface bonding and the position with peeling of the interface, the laser vibration meter identifies the damage size and the position of the interface based on the vibration modes, and calibrates the test ranges of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone and the high-frequency microphone according to the identification result.

Preferably, the data acquisition and analysis device mines at least the following characteristic indicators of the different sensor test signals based on a machine learning method: and the amplitude, the signal energy, the first wave sound time and the signal frequency are used as characteristic indexes of damage assessment, a mapping relation with the damage size is established, and the damage assessment based on multiple parameters is realized.

Preferably, the method is based on four working conditions of compaction-mining, compaction-mining and compaction-mining, and the damage of the combined structure interface is tested, analyzed and quantitatively calibrated.

In one aspect, a test system for detecting damage to an interface of an engineering structure is provided, which includes: the device comprises an automatic hammer serving as an excitation device, a sensor group serving as a sensing device and data acquisition and analysis equipment;

the self-powered hammer is used for knocking the surface to be detected of the combined structure to generate an excitation signal; the sensor group comprises a piezoelectric ceramic piece, a high-frequency accelerometer, an ultrasonic sensor, a low-frequency microphone, a high-frequency microphone and a laser vibration meter; the piezoelectric ceramic piece, the high-frequency accelerometer and the ultrasonic sensor are arranged on the surface to be detected of the combined structure and used for carrying out contact measurement on the generated stress wave; the low-frequency microphone, the high-frequency microphone and the laser vibration meter are arranged in front of the surface to be detected of the combined structure and used for carrying out non-contact measurement on the generated stress;

the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone, the high-frequency microphone and the laser vibration meter are all transmitted to the data acquisition and analysis equipment for processing, the data acquisition and analysis equipment excavates the mapping relation between the characteristic indexes and the damage sizes of the test signals of different sensors based on a machine learning method, and calibrates the test ranges of different sensors.

Preferably, the self-powered hammer is connected with a controller, and the controller is used for controlling the knocking force amplitude, the knocking angle and the knocking frequency of the self-powered hammer so as to generate a high-quality and repetitive excitation signal.

Preferably, the piezoceramic sheet, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone and the high-frequency microphone are respectively connected to the data acquisition and analysis equipment through coaxial cable connectors.

Preferably, the laser vibrometer is a 2D scanning doppler laser vibrometer supported by a foot rest in front of the surface to be detected of the composite structure.

Preferably, the composite structure comprises a steel-concrete composite structure, a bonded steel reinforced concrete composite structure and an FRP reinforced concrete composite structure.

Preferably, the test process of the test system comprises the following steps:

the computer used as the controller controls the knocking force amplitude, the knocking angle and the knocking frequency of the automatic hammer, and knocks the surface to be detected of the combined structure to generate a high-quality and repetitive excitation signal;

for a current measuring point, synchronously acquiring test signals of a piezoelectric ceramic piece, a high-frequency accelerometer, an ultrasonic sensor, a low-frequency microphone, a high-frequency microphone and a laser vibration meter, wherein the test signals comprise time domain waveform signals;

the data acquisition and analysis equipment checks the acquired time domain waveform signals and analyzes the signals by taking amplitude, signal energy, first wave sound time and signal frequency as characteristic indexes;

judging whether the signal variation trends of the sensors are consistent or not; if the difference is not consistent, checking the installation condition of the equipment, and restarting measurement; if the measured point is consistent with the measured point, whether interface damage exists in the current measured point is further judged;

if the current measuring point has no interface damage, knocking the next measuring point by a power hammer for testing;

if the interface damage exists in the current measuring point, carrying out encryption measurement on the periphery of the current measuring point;

judging whether interface damage exists in the encrypted measuring points; if the encrypted measuring point has no interface damage, knocking the next measuring point by a power hammer for testing; if the encrypted measuring points have interface damage, performing vibration mode test by using a laser vibration meter to determine the size and position of the damage;

the data acquisition and analysis equipment stores the test result, and mines the mapping relation between the characteristic indexes of the test signals of different sensors and the damage size based on a machine learning method to calibrate the test ranges of different sensors.

The technical scheme provided by the embodiment of the invention has the beneficial effects that at least:

the quantitative calibration method and the test system for the engineering structure interface damage detection provided by the embodiment of the invention can break through the technical bottlenecks that the standard of the existing engineering structure interface damage detection is inconsistent, the thick steel plate cannot be detected, and the small defect cannot be detected accurately, and can establish the accurate mapping relation between the characteristic indexes of different sensor test signals and the size of the interface defect by using the systematic quantitative comparison test and the machine learning method, thereby obviously improving the precision and the application range of the interface damage test.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic layout diagram of an engineering structure interface damage comprehensive test system for a steel-concrete composite structure according to an embodiment of the present invention;

FIG. 2 is a schematic layout diagram of the integrated testing system for damage to the interface of the engineering structure, provided by the embodiment of the invention, for a bonded steel reinforced concrete composite structure;

fig. 3 is a schematic structural diagram (blank-drive-blank) of the integrated testing system for damage to the interface of the engineering structure for contact and non-contact measurement according to the embodiment of the present invention;

fig. 4a, fig. 4b, and fig. 4c are schematic diagrams of compaction-mining, and compaction-mining tests, respectively, provided by an embodiment of the present invention;

fig. 5a, fig. 5b, fig. 5c, fig. 5d, and fig. 5e are schematic connection diagrams of a piezoelectric ceramic plate, a high-frequency accelerometer, an ultrasonic sensor, a low-frequency microphone, and a high-frequency microphone, respectively, according to an embodiment of the present invention;

FIG. 6 is a schematic flow chart of a testing method provided by an embodiment of the invention;

FIGS. 7a and 7b are schematic diagrams of test results of various sensors provided by embodiments of the present invention;

FIG. 8 is a schematic diagram of similarity analysis of different sensor signals provided by embodiments of the present invention.

As shown in the drawings, in order to clearly realize the structures of the embodiments of the present invention, specific structures and devices are marked in the drawings, which are only for illustrative purposes and are not intended to limit the present invention to the specific structures, devices and environments, and according to specific needs, a person skilled in the art can adjust or modify the devices and environments, and the adjusted or modified devices and environments still include the protection scope of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

The embodiment of the invention provides a quantitative calibration method and a test system for engineering structure interface damage detection, wherein fig. 1 is a schematic layout diagram of the test system for a steel-concrete combined structure, fig. 2 is a schematic layout diagram of the test system for a bonded steel reinforced concrete combined structure, and fig. 3 is a schematic structural diagram of the test system for contact and non-contact measurement.

Based on the system structures shown in fig. 1-3, the quantitative calibration method for detecting the engineering structure interface damage comprises the following steps:

knocking the surface to be detected of the combined structure by using the self-powered hammer 1 as an excitation device to generate a high-quality and repetitive excitation signal;

arranging a sensor group; the sensor group comprises a piezoelectric ceramic piece 2, a high-frequency accelerometer 3, an ultrasonic sensor 4, a low-frequency microphone 5, a high-frequency microphone 6 and a laser vibration meter 7;

the surface to be detected of the combined structure is provided with a piezoelectric ceramic piece 2, a high-frequency accelerometer 3 and an ultrasonic sensor 4, and the generated stress wave is measured in a contact mode; arranging a low-frequency microphone 5, a high-frequency microphone 6 and a laser vibration meter 7 in front of the surface to be detected of the combined structure, and carrying out non-contact measurement on the generated stress wave;

collecting test signals of the piezoelectric ceramic piece 2, the high-frequency accelerometer 3, the ultrasonic sensor 4, the low-frequency microphone 5, the high-frequency microphone 6 and the laser vibration meter 7 by using data collecting and analyzing equipment 8;

the data acquisition and analysis equipment 8 excavates the mapping relation between the characteristic indexes of the test signals of different sensors and the damage size based on a machine learning method, and calibrates the test ranges of different sensors;

the laser vibration meter 7 is used for non-contact measurement on one hand, and is used for verifying test data of the piezoelectric ceramic piece 2, the high-frequency accelerometer 3, the ultrasonic sensor 4, the low-frequency microphone 5 and the high-frequency microphone 6 on the other hand, and calibrating test ranges of the piezoelectric ceramic piece 2, the high-frequency accelerometer 3, the ultrasonic sensor 4, the low-frequency microphone 5 and the high-frequency microphone 6.

In the embodiment of the invention, the piezoelectric ceramic piece 2 and/or the ultrasonic sensor 4 are/is matched with the automatic power hammer 1 and used for carrying out impact-echo test; the high-frequency accelerometer 3 and/or the laser vibrometer 7 are matched with the automatic hammer 1 and used for carrying out impact-response test; a low frequency microphone 5 and/or a high frequency microphone 6 is/are fitted to the autonomous hammer 1 for conducting the shock-vibro-acoustic test. Among them, the shock-echo test and the shock-response test belong to contact type measurement, and the shock-acoustic vibration test and the modal test are non-contact type measurement.

Further, according to the difference of the vibration modes of the interface bonding intact position and the interface peeling position, the laser vibration meter 7 identifies the interface damage size and position based on the vibration modes, and calibrates the test ranges of the piezoelectric ceramic piece 2, the high-frequency accelerometer 3, the ultrasonic sensor 4, the low-frequency microphone 5 and the high-frequency microphone 6 according to the identification result.

Because the test frequency range of the laser vibration meter 7 is extremely wide, in the embodiment of the invention, the laser vibration meter 7 is used for performing impact-response test, and the laser vibration meter 7 is used for verifying and calibrating the test data and the test range of the sensors such as the piezoelectric ceramic piece 2, the high-frequency accelerometer 3, the ultrasonic sensor 4, the low-frequency microphone 5, the high-frequency microphone 6 and the like.

Therefore, the testing system not only can realize the integrated synchronous testing of 4 modes of impact-echo, impact-response, impact-sound vibration and modal testing, but also can realize the quantitative calibration of interface damage detection.

The test scenario shown in fig. 3 is a test scenario based on "hit empty-hit empty", and fig. 4a to 4c are schematic diagrams of test scenarios based on "hit real-hit empty", "hit real-hit real", and "hit empty-hit real", respectively. In the embodiment of the invention, based on four working conditions of compaction-mining, compaction-mining and compaction-mining, and sensing range differences of different sensors are quantified, the defect that a thick steel plate cannot be measured and a small-size defect cannot be measured is broken through, the thickness and the size of the steel plate are defined, and the test range and the application scene of the integrated test system for contact and non-contact measurement are quantified.

Further, the data acquisition and analysis device 8 mines at least the following characteristic indicators of the different sensor test signals based on a machine learning method: amplitude, signal energy, first wave sound time and signal frequency are used as characteristic indexes of damage assessment, a mapping relation with damage sizes is established, multi-parameter-based damage assessment is achieved, dependency of the damage assessment on experience of detection personnel is avoided, an efficient and accurate interface damage size identification system is established, and identification accuracy of geometrical sizes of defects is improved.

Correspondingly, the embodiment of the invention also provides a test system for detecting the damage of the engineering structure interface. According to fig. 1-3, the system comprises: the system comprises an automatic hammer 1 serving as an excitation device and a sensor group serving as an induction device, wherein the sensor group comprises a piezoelectric ceramic piece 2, a high-frequency accelerometer 3, an ultrasonic sensor 4, a low-frequency microphone 5, a high-frequency microphone 6 and a laser vibration meter 7, and the system further comprises data acquisition and analysis equipment 8.

Wherein, the automatic power hammer 1 is used for knocking the surface to be detected of the combined structure to generate an excitation signal; the piezoelectric ceramic piece 2, the high-frequency accelerometer 3 and the ultrasonic sensor 4 are arranged on the surface to be detected of the combined structure and used for carrying out contact measurement on the generated stress wave; the low-frequency microphone 5, the high-frequency microphone 6 and the laser vibration meter 7 are arranged in front of the surface to be detected of the combined structure and used for carrying out non-contact measurement on the generated stress waves.

Test signals of the piezoelectric ceramic piece 2, the high-frequency accelerometer 3, the ultrasonic sensor 4, the low-frequency microphone 5, the high-frequency microphone 6 and the laser vibration meter 7 are all transmitted to the data acquisition and analysis equipment 8 for processing, the data acquisition and analysis equipment 8 excavates the mapping relation between characteristic indexes and damage sizes of the test signals of different sensors based on a machine learning method, and the test ranges of the different sensors are calibrated.

In the embodiment of the invention, the automatic power hammer 1 is connected with a controller (such as a computer), and the controller can control parameters such as the amplitude of the knocking force, the knocking angle and the knocking frequency of the automatic power hammer 1 so as to generate a high-quality and repetitive excitation signal.

In the embodiment of the present invention, the piezoelectric ceramic plate 2, the high frequency accelerometer 3, the ultrasonic sensor 4, the low frequency microphone 5, and the high frequency microphone 6 are respectively connected to the data acquisition and analysis device 8 through coaxial cable connectors BNC, as shown in fig. 5a to 5 e.

In the existing impact-sound vibration and impact-response tests, a conventional low-frequency microphone is adopted to collect sound signals, and a low-frequency accelerometer is adopted to collect vibration signals of a steel plate at a defect. When the size of the interface defect is small and the thickness of the steel plate is large, the frequency of the sound signal and the vibration signal will exceed 20kHZ. The invention introduces the high-frequency microphone, the frequency of the sound signal which can be sensed by the high-frequency microphone is 100kHz at most, the frequency of the vibration signal which can be sensed by the high-frequency accelerometer is 60kHz, the limitation of the limited sensing range of the existing shock-sound vibration and shock-response test is broken through, and the precision and the applicable scene of the shock-sound vibration and shock-response test are improved.

Further, the laser vibrometer 7 adopted in the embodiment of the present invention is a 2D scanning doppler laser vibrometer, and is supported in front of the surface to be detected of the combined structure by a foot rest 9. The laser vibration meter 7 can be used for shock-response testing and modal testing, so that the interface damage size and position can be accurately analyzed, and the testing ranges of the piezoelectric ceramic piece 2, the high-frequency accelerometer 3, the ultrasonic sensor 4, the low-frequency microphone 5 and the high-frequency microphone 6 can be verified and calibrated.

The composite structure applicable to the test system provided by the invention comprises but is not limited to a steel-concrete composite structure, a bonded steel reinforced concrete composite structure, an FRP reinforced concrete composite structure and the like.

As shown in fig. 6, the test process of the test system includes the following steps:

the computer used as the controller controls the knocking force amplitude, the knocking angle and the knocking frequency of the automatic hammer, and knocks the surface to be detected of the combined structure to generate a high-quality and repetitive excitation signal;

for a current measuring point, synchronously acquiring test signals of a piezoelectric ceramic piece, a high-frequency accelerometer, an ultrasonic sensor, a low-frequency microphone, a high-frequency microphone and a laser vibration meter, wherein the test signals comprise time domain waveform signals;

the data acquisition and analysis equipment checks the acquired time domain waveform signals and analyzes the signals by taking amplitude, signal energy, first wave sound time and signal frequency as characteristic indexes;

judging whether the signal variation trends of the sensors are consistent or not; if the difference is not consistent, checking the installation condition of the equipment, and restarting measurement; if the current measuring point is consistent with the current measuring point, whether interface damage exists at the current measuring point is further judged;

if the current measuring point has no interface damage, knocking the next measuring point by a power hammer for testing;

if the interface damage exists in the current measuring point, carrying out encryption measurement on the periphery of the current measuring point;

judging whether interface damage exists in the encrypted measuring points; if the encrypted measuring point has no interface damage, knocking the next measuring point by a power hammer for testing; if the encrypted measuring points have interface damage, performing vibration mode test by using a laser vibration meter to determine the size and position of the damage;

the data acquisition and analysis equipment stores the test result, and mines the mapping relation between the characteristic indexes of the test signals of different sensors and the damage size based on a machine learning method to calibrate the test ranges of different sensors.

The test results based on one embodiment of the above test method are shown in fig. 7 a-7 b and fig. 8. Fig. 7 a-7 b show time domain test signals for individual sensors, and fig. 8 shows the results of similarity analysis for different sensor signals.

According to the invention, by mining the characteristic indexes of the test signals of different sensors, and utilizing a systematic quantitative comparison test and a machine learning method, an accurate mapping relation between the characteristic indexes of the test signals of different sensors and the size of the interface defect is established, and quantitative calibration is carried out on the test ranges of other sensors through the laser vibration meter, so that the precision and the application range of the interface damage test are obviously improved.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or terminal apparatus that comprises the element.

References in the specification to "one embodiment," "an example embodiment," "some embodiments," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the relevant art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

In general, terms may be understood at least in part from the context in which they are used. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in the singular or may be used to describe a combination of features, structures, or characteristics in the plural, depending at least in part on the context. Additionally, the term "based on" may be understood as not necessarily intended to convey an exclusive set of factors, but may instead allow for the presence of other factors not necessarily explicitly described, depending at least in part on the context.

It is understood that the meaning of "on … …", "above … …" and "above … …" in this disclosure should be interpreted in the broadest manner such that "on … …" means not only "directly on" something "but also includes the meaning of" on "something with intervening features or layers in between, and" on … … "or" above … … "means not only the meaning of" on "or" above "something, but may also include the meaning of" on "or" above "something without intervening features or layers in between.

Furthermore, spatially relative terms such as "below …", "below …", "lower", "above …", "upper", and the like may be used herein for descriptive convenience to describe the relationship of one element or feature to another element or feature, as shown in the figures. Spatially relative terms are intended to encompass different orientations in use or operation of the device in addition to the orientation depicted in the figures. The device may be otherwise oriented and the spatially relative descriptors used herein interpreted accordingly.

The invention is intended to cover alternatives, modifications, equivalents, and alternatives that may be included within the spirit and scope of the invention. In the following description of the preferred embodiments of the present invention, specific details are set forth in order to provide a thorough understanding of the present invention, and it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and the like have not been described in detail as not to unnecessarily obscure aspects of the present invention.

Those skilled in the art will appreciate that all or part of the steps in the method for implementing the above embodiments may be implemented by relevant hardware instructed by a program, and the program may be stored in a computer readable storage medium, such as: ROM/RAM, magnetic disk, optical disk, etc.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. A quantitative calibration method for detecting the damage of an engineering structure interface is characterized by comprising the following steps:

knocking the surface to be detected of the combined structure by using an automatic power hammer as an excitation device to generate a repetitive excitation signal;

arranging a sensor group; the sensor group comprises a piezoelectric ceramic piece, a high-frequency accelerometer, an ultrasonic sensor, a low-frequency microphone, a high-frequency microphone and a laser vibration meter;

the piezoelectric ceramic piece, the high-frequency accelerometer and the ultrasonic sensor are arranged on the surface to be detected of the combined structure and used for carrying out contact measurement on the generated stress wave; the low-frequency microphone, the high-frequency microphone and the laser vibration meter are arranged in front of the surface to be detected of the combined structure and used for carrying out non-contact measurement on the generated stress;

collecting test signals of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone, the high-frequency microphone and the laser vibration meter by using data collecting and analyzing equipment;

the data acquisition and analysis equipment excavates the mapping relation between the characteristic indexes of the test signals of different sensors and the damage size based on a machine learning method, and calibrates the test ranges of different sensors;

the laser vibration meter is used for non-contact measurement on one hand, and is used for verifying test data of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone and the high-frequency microphone on the other hand, and calibrating test ranges of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone and the high-frequency microphone on the other hand.

2. The quantitative calibration method for detecting the engineering structure interface damage according to claim 1, wherein the piezoelectric ceramic plate and/or the ultrasonic sensor is/are matched with the automatic hammer for performing an impact-echo test;

the high-frequency accelerometer and/or the laser vibration meter are matched with the automatic hammer for performing impact-response test;

and the low-frequency microphone and/or the high-frequency microphone are matched with the automatic hammer for carrying out impact-sound vibration test.

3. The quantitative calibration method for the engineering structure interface damage detection according to claim 1, wherein the laser vibration meter identifies the interface damage size and position based on the vibration mode according to the difference of the vibration modes of the interface bonding intact position and the interface peeling position, and calibrates the test ranges of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone and the high-frequency microphone according to the identification result.

4. The quantitative calibration method for engineering structure interface damage detection according to claim 1, wherein the data acquisition and analysis device mines at least the following characteristic indicators of different sensor test signals based on a machine learning method: the amplitude, the signal energy, the first wave sound time and the signal frequency are used as characteristic indexes of damage assessment, a mapping relation with the damage size is established, and multi-parameter-based damage assessment is achieved.

5. The quantitative calibration method for detecting the interface damage of the engineering structure according to claim 1, wherein the method is based on four working conditions of compaction-mining, compaction-mining and compaction-mining, and the interface damage of the combined structure is tested, analyzed and quantitatively calibrated.

6. A test system for detecting damage to an interface of an engineering structure, comprising: the device comprises an automatic hammer serving as an excitation device, a sensor group serving as a sensing device and data acquisition and analysis equipment;

the self-powered hammer is used for knocking the surface to be detected of the combined structure to generate an excitation signal; the sensor group comprises a piezoelectric ceramic piece, a high-frequency accelerometer, an ultrasonic sensor, a low-frequency microphone, a high-frequency microphone and a laser vibration meter; the piezoelectric ceramic piece, the high-frequency accelerometer and the ultrasonic sensor are arranged on the surface to be detected of the combined structure and used for performing contact measurement on generated stress waves; the low-frequency microphone, the high-frequency microphone and the laser vibration meter are arranged in front of the surface to be detected of the combined structure and used for carrying out non-contact measurement on the generated stress;

the test signals of the piezoelectric ceramic piece, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone, the high-frequency microphone and the laser vibration meter are all transmitted to the data acquisition and analysis equipment for processing, and the data acquisition and analysis equipment excavates the mapping relation between the characteristic indexes and the damage sizes of the test signals of different sensors based on a machine learning method and calibrates the test ranges of different sensors.

7. The engineering structure interface damage detection test system according to claim 6, wherein the self-powered hammer is connected to a controller, and the controller is configured to control the tapping force amplitude, the tapping angle and the tapping frequency of the self-powered hammer to generate a repetitive excitation signal.

8. The engineering structure interface damage detection test system according to claim 6, wherein the piezoceramic wafer, the high-frequency accelerometer, the ultrasonic sensor, the low-frequency microphone and the high-frequency microphone are respectively connected to the data acquisition and analysis equipment through coaxial cable connectors.

9. The engineering structure interface damage detection test system according to claim 6, wherein the laser vibrometer is a 2D scanning Doppler laser vibrometer supported by a foot rest in front of the surface to be detected of the composite structure.

10. The system for testing damage detection to an engineering structure interface according to claim 6, wherein the testing process of the testing system comprises the following steps:

the computer used as the controller controls the knocking force amplitude, the knocking angle and the knocking frequency of the automatic hammer, and knocks the surface to be detected of the combined structure to generate a repetitive excitation signal;

for a current measuring point, synchronously acquiring test signals of a piezoelectric ceramic piece, a high-frequency accelerometer, an ultrasonic sensor, a low-frequency microphone, a high-frequency microphone and a laser vibration meter, wherein the test signals comprise time domain waveform signals;

the data acquisition and analysis equipment checks the acquired time domain waveform signals and analyzes the signals by taking amplitude, signal energy, first wave sound time and signal frequency as characteristic indexes;

judging whether the signal variation trends of the sensors are consistent or not; if the difference is not consistent, checking the equipment installation condition, and restarting to measure; if the current measuring point is consistent with the current measuring point, whether interface damage exists at the current measuring point is further judged;

if the current measuring point has no interface damage, knocking the next measuring point by a power hammer for testing;

if the interface damage exists in the current measuring point, carrying out encryption measurement on the periphery of the current measuring point;

judging whether interface damage exists in the encrypted measuring points; if the encrypted measuring point has no interface damage, knocking the next measuring point by a power hammer for testing; if the encrypted measuring points have interface damage, performing vibration mode test by using a laser vibration meter to determine the size and position of the damage;

the data acquisition and analysis equipment stores the test result, and mines the mapping relation between the characteristic indexes of the test signals of different sensors and the damage size based on a machine learning method to calibrate the test ranges of different sensors.

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