Piezoelectric ceramic self-generating and detecting system for steel tube concrete structure detection
By emitting ultrasonic waves inside the steel pipe concrete structure and using the electrical energy of the piezoelectric ceramic sheet to generate, the problem of limited detection depth of the ultrasonic method is solved, efficient structural damage detection is achieved, and detection difficulty and damage to the structure is reduced.
Patent Information
- Application Number
- CN202110953377.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-08-19
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2041-08-19
AI Technical Summary
When detecting the concrete structure of steel pipes, the waveform is complex and the energy attenuation is severe, resulting in limited detection depth and inability to fully reflect the internal defects of the structure.
The self-generated power detection system of piezoelectric ceramics is used to detect structural damage by emitting ultrasonic waves inside the structure and using the mechanical energy of the piezoelectric ceramic sheet to convert electrical energy. The system includes piezoelectric elements, first and second piezoelectric types. Ultrasonic transducers, power amplifier circuits and small power supplies are partially packaged in a steel sealed cube, and some parts are placed outside the structure.
The depth of ultrasonic detection is improved, the damage to the structure is reduced, the detection is achieved without external power supply, the detection difficulty is reduced, and the feedback signal quality is enhanced for the internal defects of the structure.
Smart Images
Figure CN113671045B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a piezoelectric ceramic self-generating and detecting system and method for detecting steel tube concrete structures, and specifically designs a system and method for emitting ultrasonic waves inside a structure for detection, belonging to the field of structural detection. Background Art
[0002] Among the existing instruments for detecting structural damage, the ultrasonic method is one of the most widely used non-destructive testing methods. The current mainstream application principle is the ultrasonic pulse echo method, which reflects internal defects through the amplitude attenuation and waveform distortion of the echo. However, the ultrasonic pulse echo method has two main problems. First, the waveform is complex. The emitted ultrasonic waves will undergo complex reflections and scattering inside the structure, making the rebounded ultrasonic waves unable to fully reflect the inside of the structure. Second, the energy attenuation of the ultrasonic wave is serious. When the ultrasonic wave propagates in the medium, it rubs against the medium and generates considerable heat dissipation, resulting in limited detection depth of the echo method.
[0003] Ultrasonic transducers can realize the conversion of sound energy into electrical energy. Among them, piezoelectric transducers require less materials, are cheap, have high sound-to-electricity conversion efficiency, and are suitable for ultrasonic propagation in various media.
[0004] When ultrasonic waves propagate in concrete and cement mortar, they will attenuate their frequency and amplitude to a certain extent. The higher the frequency and the longer the propagation distance, the greater the attenuation.
[0005] When the structure is subjected to external excitation with a frequency that is the same as or close to its natural frequency, the structure will produce periodic vibrations of a certain amplitude, where the amplitude of the vibration is determined by the external excitation energy. Summary of the invention
[0006] The present invention aims to provide a piezoelectric ceramic self-generating-detection system and method for steel tube concrete structure detection, which is used to detect fixed position structures and specific positions of structures, improve the depth of ultrasonic detection, reduce damage to the structure, and reduce the difficulty of depth detection.
[0007] The present invention overcomes the shortcomings of the prior art, increases the depth of ultrasonic detection, fully utilizes the ability of piezoelectric ceramics to convert mechanical energy into electrical energy, and realizes the emission of ultrasonic waves from the inside of the structure, thereby realizing the detection of structural damage. The steel sheet is excited by ultrasound to vibrate, causing the piezoelectric ceramic sheet to vibrate periodically and generate voltage.
[0008] The piezoelectric ceramic self-generation-detection system provided by the present invention is partially encapsulated in a steel closed cube, and some detection components are placed outside the steel tube concrete structure to be measured, ensuring that the self-generation system will not be affected by work due to large deformation caused by force when buried inside the steel tube concrete structure.
[0009] The present invention provides a piezoelectric ceramic self-generating and detecting system for steel tube concrete structure detection, wherein the self-generating and detecting system is partially encapsulated in a steel closed cube, and part of the detecting components are placed outside the steel tube concrete structure to be detected; the system comprises: a piezoelectric element, a first piezoelectric ultrasonic transducer (50kHz), a power amplifier circuit, an internal small power supply (5V), a second piezoelectric ultrasonic transducer (100kHz), and a steel closed cube. The piezoelectric element is composed of a piezoelectric ceramic sheet, a steel sheet carrying the piezoelectric ceramic sheet, and a support plate for fixing the steel sheet.
[0010] The first piezoelectric ultrasonic transducer (50kHz) in the detection system is attached to the outer wall of the steel tube concrete to be measured, and the remaining equipment is placed in a steel closed cube and pre-buried in the steel tube concrete at the position where the measurement is required. The components in the steel closed cube are connected by electrical wires; the power amplifier circuit is attached to the side of the steel closed cube opposite to the piezoelectric element; the second piezoelectric ultrasonic transducer is attached to the lower part of the steel closed cube.
[0011] Furthermore, the first piezoelectric ultrasonic transducer (50kHz) provides vibration excitation for the steel sheet and can receive ultrasonic waves with a frequency of about 50kHz.
[0012] Furthermore, the vibration of the steel sheet can cause the piezoelectric ceramic sheet glued to the steel sheet to vibrate together, causing periodic deformation.
[0013] Furthermore, one end of the steel sheet is a free end, and the other end is rigidly connected to the restraining end of the steel sheet by welding.
[0014] Furthermore, the internal small power supply (5V) provides voltage for the power amplifier circuit.
[0015] Furthermore, the power amplifier circuit can amplify the voltage generated by the piezoelectric ceramic to a threshold that satisfies the piezoelectric ultrasonic transducer (100kHz) for emitting ultrasonic waves, and the power amplifier circuit is connected to the piezoelectric ceramic via an electrical conductor.
[0016] Furthermore, the second piezoelectric ultrasonic transducer (100kHz) can generate piezoelectric 100kHz ultrasonic waves using the amplified voltage.
[0017] The present invention provides a piezoelectric ceramic self-generation-detection method for steel tube concrete structure detection, which uses the above system for detection and includes the following steps:
[0018] (1) The piezoelectric element, the power amplifier circuit and the second piezoelectric ultrasonic transducer are connected by electrical wires and placed in a steel sealed cube. After the piezoelectric element support plate and the steel sealed cube are welded and fixed, the steel sealed cube is sealed. The sealing system is hereinafter referred to as a piezoelectric ceramic self-generating-detecting system.
[0019] (2) Before the steel tube concrete is poured and formed, the piezoelectric ceramic self-generation-detection system is placed at the key position where detection is required in the future and buried in the steel tube concrete. After the concrete hardens and forms, the position of the steel closed cube can be fixed.
[0020] (3) After the steel tube concrete structure is formed, when inspection is required, the inspector holds the first piezoelectric ultrasonic transducer close to the outside of the steel tube concrete where the piezoelectric ceramic self-power-detection system is embedded, and the distance from the piezoelectric ceramic self-power-detection system shall not exceed 1m;
[0021] (4) After all the detection equipment are placed at the target location, the detection personnel turn on the first piezoelectric ultrasonic transducer to emit ultrasonic waves with a frequency of 50 kHz to the piezoelectric ceramic self-generation-detection system, and can simultaneously receive the ultrasonic signal fed back by the piezoelectric ceramic self-generation-detection system.
[0022] (5) After collecting the target signal, the inspector retracts the first handheld piezoelectric ultrasonic transducer.
[0023] (6) By comparing the ultrasonic signals emitted and received by the inspector's handheld 50kHz ultrasonic transducer, the key parts of the steel tube concrete can be inspected.
[0024] Beneficial effects of the present invention:
[0025] The detection system of the present invention generates electricity through the deformation of piezoelectric ceramics, thereby achieving the purpose of not requiring external power supply; at the same time, a piezoelectric ultrasonic transducer is used inside the structure to achieve ultrasonic waves of a specified frequency inside the structure to achieve the measurement purpose, thereby reducing the energy dissipation of ultrasonic waves in the ultrasonic rebound method and increasing the detection depth. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 The figure is a schematic diagram of the functional implementation flow of the present invention.
[0027] Figure 2 Schematic diagram of a piezoelectric element.
[0028] Figure 3 This is a schematic diagram of the power amplifier circuit.
[0029] Figure 4 Schematic diagram of the application of testing equipment in steel tube concrete.
[0030] Figure 5 This is a connection diagram of the internal components of the detection equipment.
[0031] In the figure: 1 is a piezoelectric element, 2 is a power amplifier circuit, 3 is a second piezoelectric ultrasonic transducer, 4 is a first piezoelectric ultrasonic transducer, 5 is a steel sealed cube, 101 is a piezoelectric ceramic sheet, 102 is a steel sheet, and 103 is a support plate. DETAILED DESCRIPTION
[0032] The present invention is further illustrated by the following examples, but is not limited to the following examples.
[0033] Embodiment 1:
[0034] like Figures 1 to 5 As shown, a piezoelectric ceramic self-generating and detecting system for steel tube concrete structure detection is partially encapsulated in a steel sealed cube, and some detection components are placed outside the steel tube concrete structure to be detected; the system includes: a piezoelectric element, a first piezoelectric ultrasonic transducer 4 (50kHz), a power amplifier circuit 2, an internal small power supply (5V), a second piezoelectric ultrasonic transducer 3 (100kHz), and a steel sealed cube. The piezoelectric element is composed of a piezoelectric ceramic sheet 101, a steel sheet 102 carrying the piezoelectric ceramic sheet, and a support plate 103 for fixing the steel sheet.
[0035] The first piezoelectric ultrasonic transducer (50kHz) in the detection system is attached to the outer wall of the steel tube concrete to be measured, and the remaining equipment is placed in a steel closed cube and pre-buried in the steel tube concrete at the position where the measurement is required. The components in the steel closed cube are connected by electrical wires; the power amplifier circuit is attached to the side of the steel closed cube opposite to the piezoelectric element; the second piezoelectric ultrasonic transducer is attached to the lower part of the steel closed cube.
[0036] Furthermore, the first piezoelectric ultrasonic transducer (50kHz) provides vibration excitation for the steel sheet and can receive ultrasonic waves with a frequency of about 50kHz.
[0037] Furthermore, the vibration of the steel sheet can cause the piezoelectric ceramic sheet adhered to the steel sheet to vibrate together, causing periodic deformation.
[0038] Furthermore, one end of the steel sheet is a free end, and the other end is rigidly connected to the restraining end of the steel sheet by welding.
[0039] Furthermore, the small power supply (5V) of the power amplifier circuit provides the required voltage for power amplification.
[0040] Furthermore, the power amplifier circuit can amplify the voltage generated by the piezoelectric ceramic to a threshold that satisfies the piezoelectric ultrasonic transducer (100kHz) for emitting ultrasonic waves, and the power amplifier circuit is connected to the piezoelectric ceramic via an electrical conductor.
[0041] Furthermore, the second piezoelectric ultrasonic transducer (100kHz) can generate piezoelectric 100kHz ultrasonic waves using the amplified voltage.
[0042] The present invention provides a piezoelectric ceramic self-generation-detection method for steel tube concrete structure detection, which uses the above system for detection and includes the following steps:
[0043] (1) The piezoelectric element, the power amplifier circuit and the second piezoelectric ultrasonic transducer are connected by electrical wires and placed in a steel sealed cube. After the piezoelectric element support plate and the steel sealed cube are welded and fixed, the steel sealed cube is sealed. The sealing system is hereinafter referred to as a piezoelectric ceramic self-generating-detecting system.
[0044] (2) Before the steel tube concrete is poured and formed, the piezoelectric ceramic self-generation-detection system is placed at the key position where detection is required in the future and buried in the steel tube concrete. After the concrete hardens and forms, the position of the steel closed cube can be fixed.
[0045] (3) After the steel tube concrete structure is formed, when inspection is required, the inspector holds the first piezoelectric ultrasonic transducer close to the outside of the steel tube concrete where the piezoelectric ceramic self-power-detection system is embedded, and the distance from the piezoelectric ceramic self-power-detection system shall not exceed 1m;
[0046] (4) After all the detection equipment are placed at the target location, the detection personnel turn on the first piezoelectric ultrasonic transducer to emit ultrasonic waves with a frequency of 50 kHz to the piezoelectric ceramic self-generation-detection system, and can simultaneously receive the ultrasonic signal fed back by the piezoelectric ceramic self-generation-detection system.
[0047] (5) After collecting the target signal, the inspector retracts the first handheld piezoelectric ultrasonic transducer.
[0048] (6) By comparing the ultrasonic signals emitted and received by the inspector's handheld 50kHz ultrasonic transducer, the key parts of the steel tube concrete can be inspected.
Claims
1. A piezoelectric ceramic self-generating and detecting system for steel tube concrete structure detection, characterized in that: It includes a piezoelectric element, a first piezoelectric ultrasonic transducer, a power amplifier circuit, an internal small power supply, a second piezoelectric ultrasonic transducer, and a steel sealed cube; the piezoelectric element is composed of a piezoelectric ceramic sheet, a steel sheet carrying the piezoelectric ceramic sheet, and a support plate for fixing the steel sheet; the first piezoelectric ultrasonic transducer is attached to the outer wall of the steel tube concrete to be measured, and the remaining equipment is placed in the steel sealed cube and pre-buried in the steel tube concrete at the position where the measurement is required; the components located in the steel sealed cube are connected by electrical wires; the power amplifier circuit is attached to the side of the steel sealed cube opposite to the piezoelectric element; the second piezoelectric ultrasonic transducer is attached to the lower part of the steel sealed cube; The first piezoelectric ultrasonic transducer provides vibration excitation for the steel sheet and emits ultrasonic waves with a frequency of 50kHz; the second piezoelectric ultrasonic transducer generates ultrasonic waves of 100kHz using the amplified voltage; The vibration of the steel sheet can make the piezoelectric ceramic sheet glued to the steel sheet vibrate together, causing periodic deformation; one end of the steel sheet is a free end, and the other end is rigidly connected to the constraint end of the steel sheet by welding; the power amplifier circuit amplifies the voltage generated by the piezoelectric ceramic sheet to a threshold value that meets the second piezoelectric ultrasonic transducer to emit ultrasonic waves, and the power amplifier circuit is connected to the piezoelectric ceramic sheet through an electrical conductor.
2. The piezoelectric ceramic self-generating and detecting system for steel tube concrete structure detection according to claim 1 is characterized in that: The internal small power supply provides voltage for the power amplifier circuit.
3. A piezoelectric ceramic self-generation detection method for steel tube concrete structure detection, using the system described in any one of claims 1 to 2 for detection, characterized in that The following steps are involved: (1) connecting the piezoelectric element, the power amplifier circuit and the second piezoelectric ultrasonic transducer through an electrical conductor and placing them in a steel sealed cube. After the piezoelectric element support plate and the steel sealed cube are welded and fixed, the steel sealed cube is sealed. (2) Before the steel tube concrete is poured and formed, the steel closed cube is placed at the key position required for future inspection and buried in the steel tube concrete. After the concrete hardens and forms, the position of the steel closed cube can be fixed; (3) After the steel tube concrete structure is formed, when testing is required, the inspector holds the first piezoelectric ultrasonic transducer close to the outside of the steel tube concrete where the steel sealed cube is buried, and the distance from the steel sealed cube should not exceed 1m; (4) After all the testing equipment is placed at the target position, the testing personnel turns on the first piezoelectric ultrasonic transducer to emit ultrasonic waves with a frequency of 50 kHz to the steel sealed cube, and can simultaneously receive the ultrasonic signal fed back by the steel sealed cube; (5) After collecting the target signal, the inspector retracts the first piezoelectric ultrasonic transducer held in his hand; (6) By comparing the ultrasonic signal emitted by the first piezoelectric ultrasonic transducer held by the inspector with the ultrasonic signal received, the key parts of the steel tube concrete are inspected.