CN111521681A - Concrete internal damage assessment method based on piezoelectric ceramic shear wave energy loss - Google Patents
Concrete internal damage assessment method based on piezoelectric ceramic shear wave energy loss Download PDFInfo
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- CN111521681A CN111521681A CN202010447699.1A CN202010447699A CN111521681A CN 111521681 A CN111521681 A CN 111521681A CN 202010447699 A CN202010447699 A CN 202010447699A CN 111521681 A CN111521681 A CN 111521681A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/043—Analysing solids in the interior, e.g. by shear waves
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/045—Analysing solids by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/24—Probes
- G01N29/2437—Piezoelectric probes
- G01N29/245—Ceramic probes, e.g. lead zirconate titanate [PZT] probes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
- G01N29/4409—Processing the detected response signal, e.g. electronic circuits specially adapted therefor by comparison
Abstract
The invention discloses a concrete internal damage assessment method based on piezoelectric ceramic shear wave energy loss, wherein a piezoelectric ceramic sensor is arranged on the surface of a concrete structure, the change of shear waves after passing through the concrete structure is monitored, a damage signal is collected and is converted from a time domain signal to a frequency domain signal for analysis, the position of a crack is judged by comparing the signal energy loss value of the damage state of a measurement part in different measurement stages with that in the intact state, and when the damage signal energy value is calculated, the influence of low-frequency noise and high-frequency noise can be eliminated by selecting a frequency analysis range, so that the interference is reduced, and the accuracy of crack position judgment is effectively improved; meanwhile, the tool applied by the method is simple and is convenient to operate on the engineering site, and the method is used in the technical field of concrete structure health monitoring.
Description
Technical Field
The invention relates to the technical field of concrete structure health monitoring, in particular to a method for evaluating concrete internal damage based on piezoelectric ceramic shear wave energy loss.
Background
Cracks have great influence on the bearing capacity and durability of a concrete structure, the cracks in the concrete are difficult to monitor, the size, the development process and the position of the cracks in the concrete are important indexes for judging the health condition of the concrete structure, and therefore, how to accurately monitor the cracks in the concrete becomes a problem which needs to be solved urgently.
The piezoelectric ceramic sensor has the driving and sensing functions, and the technology for monitoring the internal crack of the concrete structure by using the piezoelectric ceramic sensor is mature and widely applied in practice. At present, the crack is monitored by applying a piezoelectric ceramic sensor, and the size of the crack is mainly determined according to the wave velocity change of the collected shear wave and the amplitude change of the shear wave in a time domain. However, engineering practice shows that the wave velocity is difficult to accurately determine under the influence of stress waves and noise, the time domain signal amplitude error is large under the influence of alternating voltage frequency and site noise, the signal acquisition requirement is high, and the method is difficult to realize on an engineering site.
Disclosure of Invention
The invention aims to solve at least one technical problem in the prior art and provides a concrete internal damage assessment method based on piezoelectric ceramic shear wave energy loss, which is applicable to engineering sites and accurate in judgment.
According to the embodiment of the invention, the method for evaluating the internal damage of the concrete based on the shear wave energy loss of the piezoelectric ceramics comprises the following steps: s1, respectively arranging a plurality of piezoelectric ceramic sensors on two opposite surfaces of the concrete structure; s2, determining a plurality of measurement stages, wherein in each measurement stage, a piezoelectric ceramic sensor is respectively selected as a driver and a receiver on two opposite surfaces, the driver and the receiver are connected to a crack monitoring system, vibration is generated by the driver during measurement, the vibration is transmitted to the receiver through a concrete structure in the form of shear waves, and signals collected by the receiver are damage signals; s3, converting the damage signals of each measurement stage into frequency domain signals from time domain signals by using a formula; s4, selecting frequency analysis range, and calculating to obtain damage signal energy value E in each measurement stagej(ii) a S5, determining the signal energy loss value DI of each measurement stage,
in the formula E0The signal energy value of the same position of the concrete structure in a complete state; s6, comparing the signal energy loss of each measuring stageAnd (4) loss value DI, and judging the position of the crack in the concrete structure.
The method for evaluating the internal damage of the concrete based on the energy loss of the shear waves of the piezoelectric ceramics has the following beneficial effects: the method for evaluating the internal damage of the concrete based on the energy loss of the piezoelectric ceramic shear wave comprises the steps of arranging a piezoelectric ceramic sensor on the surface of the concrete structure, monitoring the change of the shear wave after passing through the concrete structure, collecting damage signals, converting the damage signals into frequency domain signals from time domain signals for analysis, comparing the damage states of measurement parts at different measurement stages with the signal energy loss values in the intact state to judge the position of a crack, and eliminating the influence of low-frequency noise and high-frequency noise by selecting a frequency analysis range when calculating the energy value of the damage signals, so that the interference is reduced, and the accuracy of crack position judgment is effectively improved; meanwhile, the tool applied by the method is simple and is convenient to operate on the engineering site.
According to some embodiments of the invention, the crack monitoring system comprises a signal generator, a signal amplifier and an oscilloscope, wherein the signal generator is connected with the driver, the input end of the signal amplifier is connected with the receiver, and the output end of the signal amplifier is connected with the oscilloscope.
According to some embodiments of the invention, the formula in step S3 is
X (ω) in the formula is a discrete signal sequence in the frequency domain; x (t) is a discrete signal sequence in the time domain signal; t is the time in the time domain signal; ω is the frequency in the frequency domain signal.
According to some embodiments of the invention, in the step S4, the frequency analysis range is selected from 0.5kHz to 10 kHz.
According to some embodiments of the invention, the impairment signal energy value EjIs calculated by the formula
Wherein XiFor the ith dispersion in the frequency domain of each measurement stageThe amplitude of the signal.
According to some embodiments of the invention, the piezoceramic sensors distributed on the same surface of the concrete structure are distributed in the form of a matrix.
According to some embodiments of the invention, the number of piezoceramic sensors on two opposing surfaces of the concrete structure is uniform.
Drawings
The invention will be further described with reference to the accompanying drawings in which:
FIG. 1 is a schematic diagram of the distribution of piezoceramic sensors in an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.
In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.
In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.
Referring to fig. 1, the method for evaluating concrete internal damage based on piezoelectric ceramic shear wave energy loss according to the embodiment of the invention comprises the following steps:
s1, respectively arranging a plurality of piezoelectric ceramic sensors on two opposite surfaces of the concrete structure;
s2, determining a plurality of measurement stages, wherein in each measurement stage, a piezoelectric ceramic sensor is respectively selected as a driver and a receiver on two opposite surfaces, the driver and the receiver are connected to a crack monitoring system, vibration is generated by the driver during measurement, the vibration is transmitted to the receiver through a concrete structure in the form of shear waves, and signals collected by the receiver are damage signals;
s3, converting the damage signal of each measurement stage from the time domain signal to the frequency domain signal by a formula, wherein the specific conversion formula is
Wherein X (ω) is a discrete signal sequence in the frequency domain, X (t) is a discrete signal sequence in the time domain signal, t is time in the time domain signal, and ω is frequency in the frequency domain signal;
s4, selecting frequency analysis range, and calculating to obtain damage signal energy value E in each measurement stagej；
S5, determining the signal energy loss value DI of each measurement stage,
in the formula E0The signal energy value of the same position of the concrete structure in a good state, specifically, the E of the corresponding position of each measurement stage0The test time of the obtaining steps of (1) is as follows from S1 to S4, and the test time is before the filling of the concrete structure is completed and the load is not born;
and S6, comparing the signal energy loss value DI of each measurement stage, and judging the position of the crack in the concrete structure. Since the signal energy reduction value at the damage stage is the energy loss caused by the crack, the size of the crack can be represented by comparing the signal energy loss value.
According to the method for evaluating the internal damage of the concrete based on the energy loss of the piezoelectric ceramic shear wave, the piezoelectric ceramic sensor is arranged on the surface of the concrete structure, the change of the shear wave after passing through the concrete structure is monitored, the damage signal is collected and is converted from a time domain signal to a frequency domain signal for analysis, the position of a crack is judged by comparing the signal energy loss value of the damage state of a measurement part in different measurement stages with the signal energy loss value in the intact state, and when the energy value of the damage signal is calculated, the influence of low-frequency noise and high-frequency noise can be eliminated by selecting a frequency analysis range, so that the interference is reduced, and the accuracy of crack position judgment is effectively improved; meanwhile, the tool applied by the method is simple and is convenient to operate on the engineering site.
Specifically, the crack monitoring system of the embodiment includes a signal generator, a signal amplifier and an oscilloscope, wherein the signal generator is connected to the driver, an input end of the signal amplifier is connected to the receiver, and an output end of the signal amplifier is connected to the oscilloscope. The damage signals collected by the receiver are amplified by the signal amplifier, so that the damage signals can be displayed more clearly in the oscilloscope, the accuracy of data collection is improved, and the accuracy of crack position judgment is improved.
In the embodiment of the present invention, the frequency analysis range selected in step S4 is 0.5kHz to 10kHz to eliminate the influence of low frequency noise and high frequency noise in the engineering site. Further, the signal energy value E of the damagejIs calculated by the formula
Wherein XiIs the amplitude of the i-th discrete signal in the frequency domain of each measurement phase.
In order to improve the arrangement regularity of the piezoelectric ceramic sensors on the surface of the concrete structure, the piezoelectric ceramic sensors arranged on the same surface of the concrete structure are distributed in a matrix form. Further, the number of the piezoelectric ceramic sensors on the two opposite surfaces of the concrete structure is consistent, and the piezoelectric ceramic sensors on the two surfaces are respectively in one-to-one correspondence.
For example, damage identification of a square concrete beam is performed, three piezoelectric ceramic sensors, namely PZT1, PZT2, PZT3, PZT1-1, PZT2-1 and PZT3-1 are respectively pasted on the upper surface and the lower surface of the concrete beam, and in the embodiment, damage conditions between PZT1 and PZT1-1, PZT2 and PZT2-1 and between PZT3 and PZT3-1 are monitored. In the first measurement stage, PZT1 is used as a driver, PZT1-1 is used as a receiver, PZT1 is connected to a signal generator to send out signal excitation, a damage signal passing through a concrete beam is received by PZT1-1, and the damage signal is amplified by a signal amplifier and then collected to an oscilloscope. In the second and third measurement stages, PZT2 and PZT3 are used as drivers, PZT2-1 and PZT3-1 are used as receivers, and damage signals of different parts in the concrete beam are collected in sequence. Finally, signal energy loss values DI between PZT1 and PZT1-1, PZT2 and PZT2-1 and between PZT3 and PZT3-1 can be obtained through calculation and analysis, and the main generation position of the crack can be judged by comparing the three signal energy loss values. By analogy, the crack development process of different positions of the concrete structure can be monitored by comparing the signal energy loss values of other different positions.
The invention is not limited to the above embodiments, and those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the invention, and such equivalent modifications or substitutions are included in the scope of the claims of the present application.
Claims (6)
1. The concrete internal damage assessment method based on the shear wave energy loss of the piezoelectric ceramics is characterized by comprising the following steps of:
s1, respectively arranging a plurality of piezoelectric ceramic sensors on two opposite surfaces of the concrete structure;
s2, determining a plurality of measurement stages, wherein in each measurement stage, a piezoelectric ceramic sensor is respectively selected as a driver and a receiver on two opposite surfaces, the driver and the receiver are connected to a crack monitoring system, vibration is generated by the driver during measurement, the vibration is transmitted to the receiver through a concrete structure in the form of shear waves, and signals collected by the receiver are damage signals;
s3, converting the damage signals of each measurement stage into frequency domain signals from time domain signals by using a formula;
s4, selecting a frequency analysis range, and calculating to obtain a damage signal energy value E of each measurement stagej；
S5, determining the signal energy loss value DI of each measurement stage,
in the formula E0The signal energy value of the same position of the concrete structure in a complete state;
and S6, comparing the signal energy loss value DI of each measurement stage, and judging the position of the crack in the concrete structure.
2. The method for evaluating concrete internal damage based on piezoelectric ceramic shear wave energy loss according to claim 1, wherein: the crack monitoring system comprises a signal generator, a signal amplifier and an oscilloscope, wherein the signal generator is connected with a driver, the input end of the signal amplifier is connected with a receiver, and the output end of the signal amplifier is connected to the oscilloscope.
3. The method for evaluating concrete internal damage based on piezoelectric ceramic shear wave energy loss according to claim 1, wherein: the formula in step S3 is
Wherein X (ω) is a discrete signal sequence in the frequency domain signal, and X (t) is a discrete signal sequence in the time domain signal; t is the time in the time domain signal; ω is the frequency in the frequency domain signal.
4. The method for evaluating concrete internal damage based on piezoelectric ceramic shear wave energy loss according to claim 3, wherein: in the step S4, the selected frequency analysis range is 0.5kHz to 10 kHz.
5. The method for evaluating concrete internal damage based on piezoelectric ceramic shear wave energy loss according to claim 4, wherein: the damage signal energy value EjIs calculated by the formula
Wherein XiIs the amplitude of the i-th discrete signal in the frequency domain of each measurement phase.
6. The method for evaluating concrete internal damage based on piezoelectric ceramic shear wave energy loss according to claim 1, wherein: the piezoelectric ceramic sensors distributed on the same surface of the concrete structure are distributed in a matrix form.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112129813A (en) * | 2020-09-16 | 2020-12-25 | 南京邮电大学 | Damage assessment method based on structural damage characteristic factor connection rule |
| CN112362756A (en) * | 2020-11-24 | 2021-02-12 | 长沙理工大学 | Concrete structure damage monitoring method and system based on deep learning |
| CN112668082A (en) * | 2020-12-25 | 2021-04-16 | 大连理工大学 | Method for monitoring and evaluating concrete crack repairing effect in real time |
| CN113065388A (en) * | 2021-02-03 | 2021-07-02 | 湖南大学 | Real-time soil category identification method and system and excavator |
| CN113203690A (en) * | 2021-04-02 | 2021-08-03 | 太原理工大学 | Continuous reinforced concrete pavement crack monitoring system and method based on OFDR + EMI |
| CN113203690B (en) * | 2021-04-02 | 2024-04-26 | 太原理工大学 | Continuous reinforced concrete pavement crack monitoring system and method based on OFDR+EMI |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005083752A (en) * | 2003-09-04 | 2005-03-31 | Taiheiyo Cement Corp | Breaking sound sensor |
| CN103388378A (en) * | 2013-07-31 | 2013-11-13 | 上海交通大学 | Intelligent reinforcing steel bar based on piezoelectric ceramic crystal and fabrication method thereof |
| CN103472130A (en) * | 2013-09-10 | 2013-12-25 | 河海大学 | Piezoelectric ceramic sensitive module and hydraulic concrete structure health monitoring test platform |
| CN103995023A (en) * | 2014-04-25 | 2014-08-20 | 湖南大学 | Detection method for defect of interfacial debonding between tube wall of concrete filled steel tube member and concrete |
| CN105424802A (en) * | 2015-11-10 | 2016-03-23 | 华南理工大学 | Ultrasonic guided-wave detecting system for defect of composite insulator and detecting method of ultrasonic guided-wave detecting system |
| CN107228902A (en) * | 2017-08-10 | 2017-10-03 | 广东工业大学 | A kind of stripping damage detection system at FRP concrete bindings interface |
| CN108152158A (en) * | 2018-03-07 | 2018-06-12 | 上海交通大学规划建筑设计有限公司 | Modulus of elasticity of concrete measuring method based on surface mount formula PZT |
| CN109465173A (en) * | 2018-10-23 | 2019-03-15 | 武汉大学 | A kind of rock mass structure shearing wave transducer and preparation method based on piezoelectric ceramic micro-displacement actuator |
| CN109991244A (en) * | 2019-05-09 | 2019-07-09 | 福建工程学院 | Sleeve Grouted density detection device and method based on stress wave |
| CN110333295A (en) * | 2019-08-05 | 2019-10-15 | 河北中核岩土工程有限责任公司 | Ground core sample wave velocity testing system and method |
-
2020
- 2020-05-25 CN CN202010447699.1A patent/CN111521681A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005083752A (en) * | 2003-09-04 | 2005-03-31 | Taiheiyo Cement Corp | Breaking sound sensor |
| CN103388378A (en) * | 2013-07-31 | 2013-11-13 | 上海交通大学 | Intelligent reinforcing steel bar based on piezoelectric ceramic crystal and fabrication method thereof |
| CN103472130A (en) * | 2013-09-10 | 2013-12-25 | 河海大学 | Piezoelectric ceramic sensitive module and hydraulic concrete structure health monitoring test platform |
| CN103995023A (en) * | 2014-04-25 | 2014-08-20 | 湖南大学 | Detection method for defect of interfacial debonding between tube wall of concrete filled steel tube member and concrete |
| CN105424802A (en) * | 2015-11-10 | 2016-03-23 | 华南理工大学 | Ultrasonic guided-wave detecting system for defect of composite insulator and detecting method of ultrasonic guided-wave detecting system |
| CN107228902A (en) * | 2017-08-10 | 2017-10-03 | 广东工业大学 | A kind of stripping damage detection system at FRP concrete bindings interface |
| CN108152158A (en) * | 2018-03-07 | 2018-06-12 | 上海交通大学规划建筑设计有限公司 | Modulus of elasticity of concrete measuring method based on surface mount formula PZT |
| CN109465173A (en) * | 2018-10-23 | 2019-03-15 | 武汉大学 | A kind of rock mass structure shearing wave transducer and preparation method based on piezoelectric ceramic micro-displacement actuator |
| CN109991244A (en) * | 2019-05-09 | 2019-07-09 | 福建工程学院 | Sleeve Grouted density detection device and method based on stress wave |
| CN110333295A (en) * | 2019-08-05 | 2019-10-15 | 河北中核岩土工程有限责任公司 | Ground core sample wave velocity testing system and method |
Non-Patent Citations (2)
| Title |
|---|
| 庄志有: "基于外贴压陶瓷的钢管混凝土内部缺陷检测方法研究", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
| 许斌等: "基于外贴压电陶瓷的钢管砼界面剥离检测机理的数值模拟研究", 《应用力学学报》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112129813A (en) * | 2020-09-16 | 2020-12-25 | 南京邮电大学 | Damage assessment method based on structural damage characteristic factor connection rule |
| CN112129813B (en) * | 2020-09-16 | 2022-05-10 | 南京邮电大学 | Damage assessment method based on structural damage characteristic factor connection rule |
| CN112362756A (en) * | 2020-11-24 | 2021-02-12 | 长沙理工大学 | Concrete structure damage monitoring method and system based on deep learning |
| CN112362756B (en) * | 2020-11-24 | 2024-02-20 | 长沙理工大学 | Concrete structure damage monitoring method and system based on deep learning |
| CN112668082A (en) * | 2020-12-25 | 2021-04-16 | 大连理工大学 | Method for monitoring and evaluating concrete crack repairing effect in real time |
| CN112668082B (en) * | 2020-12-25 | 2022-11-18 | 大连理工大学 | Method for monitoring and evaluating concrete crack repairing effect in real time |
| CN113065388A (en) * | 2021-02-03 | 2021-07-02 | 湖南大学 | Real-time soil category identification method and system and excavator |
| CN113065388B (en) * | 2021-02-03 | 2022-11-01 | 湖南大学 | Real-time soil category identification method and system and excavator |
| CN113203690A (en) * | 2021-04-02 | 2021-08-03 | 太原理工大学 | Continuous reinforced concrete pavement crack monitoring system and method based on OFDR + EMI |
| CN113203690B (en) * | 2021-04-02 | 2024-04-26 | 太原理工大学 | Continuous reinforced concrete pavement crack monitoring system and method based on OFDR+EMI |
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