阅读说明：本技术 用于钢管混凝土结构检测的压电陶瓷自发电-检测系统 (Piezoelectric ceramic self-generating and detecting system for detecting steel pipe concrete structure ) 是由 路国运 卜书文 左文建 杨旭 王轶喆 杨涵笑 杨俊涛 陈鹏程 杨会伟 于 2021-08-19 设计创作，主要内容包括：本发明公开了一种用于钢管混凝土结构检测的压电陶瓷自发电-检测系统和方法。包括压电元件、第一压电型超声换能器、功率放大电路、内部小型电源、第二压电型超声换能器、钢质密闭立方体；压电元件由压电陶瓷片、承载压电陶瓷片的钢片和用于固定钢片的支撑板组成；所述第一压电型超声换能器贴附于所测钢管混凝土外壁上,其余设备均置于钢质密闭立方体内,并预先埋置于钢管混凝土中所需进行测量的位置；位于钢质密闭立方体内的各部件通过电导线相连；所述的功率放大电路粘贴到钢质密闭立方体中与压电元件相对的一侧上；所述的第二压电型超声换能器粘贴到钢质密闭立方体内的下部。(The invention discloses a piezoelectric ceramic self-generating and detecting system and method for detecting a steel pipe concrete structure. The piezoelectric ultrasonic transducer comprises a piezoelectric element, a first piezoelectric ultrasonic transducer, a power amplification circuit, an internal small power supply, a second piezoelectric ultrasonic transducer and a steel closed cube; the piezoelectric element consists of a piezoelectric ceramic piece, a steel sheet bearing the piezoelectric ceramic piece and a support plate for fixing the steel sheet; the first piezoelectric ultrasonic transducer is attached to the outer wall of the measured concrete filled steel tube, and the rest equipment is arranged in the steel closed cube and is pre-embedded in the position, required to be measured, of the concrete filled steel tube; all the parts in the steel closed cube are connected through electric leads; the power amplifying circuit is adhered to one side of the steel closed cube, which is opposite to the piezoelectric element; and the second piezoelectric ultrasonic transducer is adhered to the lower part in the steel closed cube.)

1. A piezoelectric ceramic self-generating-detection system for detecting a steel pipe concrete structure is characterized in that: the piezoelectric ultrasonic transducer comprises a piezoelectric element, a first piezoelectric ultrasonic transducer, a power amplification circuit, an internal small power supply, a second piezoelectric ultrasonic transducer and a steel closed cube; the piezoelectric element consists of a piezoelectric ceramic piece, a steel sheet bearing the piezoelectric ceramic piece and a support plate for fixing the steel sheet; the first piezoelectric ultrasonic transducer is attached to the outer wall of the measured concrete filled steel tube, and the rest equipment is arranged in the steel closed cube and is pre-embedded in the position, required to be measured, of the concrete filled steel tube; all the parts in the steel closed cube are connected through electric leads; the power amplifying circuit is adhered to one side of the steel closed cube, which is opposite to the piezoelectric element; and the second piezoelectric ultrasonic transducer is adhered to the lower part in the steel closed cube.

2. The piezoelectric ceramic self-generating-detection system for steel pipe concrete structure detection according to claim 1, wherein: the first piezoelectric ultrasonic transducer provides vibration excitation for the steel sheet and can receive ultrasonic waves with the frequency near 50 kHz.

3. The piezoelectric ceramic self-generating-detection system for steel pipe concrete structure detection according to claim 1, wherein: the vibration of the steel sheet can enable the piezoelectric ceramic pieces glued on the steel sheet to vibrate together to cause periodic deformation; one end of the steel sheet is a free end, and the other end of the steel sheet is in rigid connection with the steel sheet restraint end through welding.

4. The piezoelectric ceramic self-generating-detection system for steel pipe concrete structure detection according to claim 1, wherein: the internal small power supply supplies voltage to the power amplifying circuit.

5. The piezoelectric ceramic self-generating-detection system for steel pipe concrete structure detection according to claim 1, wherein: the power amplifying circuit can amplify the voltage generated by the piezoelectric ceramics to meet the threshold value of the piezoelectric ultrasonic transducer for emitting ultrasonic waves, and the power amplifying circuit is connected with the piezoelectric ceramics through an electric lead.

6. The piezoelectric ceramic self-generating-detection system for steel pipe concrete structure detection according to claim 1, wherein: the second piezoelectric ultrasonic transducer can generate the piezoelectric ultrasonic wave of 100kHz by using the amplified voltage.

7. A piezoelectric ceramic self-generating-detection method for detecting a steel pipe concrete structure, which is used for detection by using the system of any one of claims 1-6, and is characterized by comprising the following steps:

(1) the piezoelectric element, the power amplifying circuit and the second piezoelectric ultrasonic transducer are connected through electric leads and are placed in the steel closed cube, and the steel closed cube is sealed after the piezoelectric element supporting plate and the steel closed cube are welded and fixed;

(2) before the steel pipe concrete is poured and formed, the piezoelectric ceramic self-generating-detecting system is placed at a key position needing to be detected in the future and is embedded in the steel pipe concrete, and the position of the steel closed cube can be fixed after the concrete is hardened and formed;

(3) after the steel pipe concrete structure is formed, when detection is needed, a detector holds the first piezoelectric ultrasonic transducer in a hand and clings to the outside of the steel pipe concrete embedded with the piezoelectric ceramic self-generating-detecting system, and the distance between the first piezoelectric ultrasonic transducer and the piezoelectric ceramic self-generating-detecting system cannot exceed 1 m;

(4) after all the detection equipment is arranged at a target position, a detector starts a first piezoelectric ultrasonic transducer, sends ultrasonic waves with the frequency of 50kHz to a piezoelectric ceramic self-generating-detection system and can simultaneously receive ultrasonic signals fed back by the piezoelectric ceramic self-generating-detection system;

(5) collecting a target signal, and withdrawing the first handheld piezoelectric ultrasonic transducer by a detection person;

(6) the ultrasonic signal of sending and receiving of the handheld 50kHz ultrasonic transducer of contrast testing personnel, realize the detection to steel pipe concrete key position promptly.

Technical Field

The invention relates to a piezoelectric ceramic self-generating and detecting system and method for detecting a steel pipe concrete structure, in particular to a system and method for transmitting ultrasonic waves to detect the interior of a structure body, and belongs to the field of structure detection.

Background

Among existing instruments for detecting structural damage, the ultrasonic method is one of nondestructive detection methods with the widest application range. The current mainstream application principle is an ultrasonic pulse echo method, which reflects internal defects through echo amplitude attenuation and waveform distortion, but the ultrasonic pulse echo method has two main problems, namely, the waveform is complex, and the emitted ultrasonic waves can generate complex reflection, scattering and other phenomena in the structure, so that the rebounded ultrasonic waves can not fully reflect the inside of the structure; secondly, the energy attenuation of the ultrasonic wave is serious, and the ultrasonic wave generates considerable heat dissipation when being rubbed with the medium when being transmitted in the medium, so that the detection depth of the echo method is limited.

The ultrasonic transducer can realize the conversion of sound energy to electric energy, wherein the piezoelectric transducer needs less materials, has low price and high sound-electricity conversion efficiency and is suitable for the ultrasonic propagation in various media.

The ultrasonic wave is transmitted in concrete and cement mortar to generate attenuation of frequency and amplitude to a certain extent, and the higher the frequency is, the longer the transmission distance is, the greater the attenuation degree is.

When the structure is subjected to an external excitation frequency which is the same as or close to the natural vibration frequency, the structure generates periodic vibration with certain amplitude, wherein the amplitude of the vibration can be determined by the external excitation energy.

Disclosure of Invention

The invention aims to provide a piezoelectric ceramic self-generating and detecting system and method for detecting a steel pipe concrete structure, which are used for detecting a fixed position structure and detecting a specific position of the structure, so that the ultrasonic detection depth is improved, the damage to the structure is reduced, and the difficulty of depth detection is reduced.

The invention overcomes the defects in the prior art, improves the depth of ultrasonic detection, fully utilizes the conversion capability of mechanical energy to electric energy of piezoelectric ceramics, realizes the transmission of ultrasonic waves from the interior of the structure body and further realizes the detection of structural damage. The steel sheet is vibrated by ultrasonic excitation, so that the piezoelectric ceramic piece is periodically vibrated to generate voltage.

The piezoelectric ceramic self-generating-detecting system provided by the invention is partially encapsulated in the steel closed cube, and a part of detecting components are arranged outside the measured steel pipe concrete structure, so that the self-generating system is prevented from being greatly deformed due to stress to influence the work when being buried in the steel pipe concrete structure.

The invention provides a piezoelectric ceramic self-generating-detecting system for detecting a steel pipe concrete structure, wherein part of the self-generating-detecting system is encapsulated in a steel closed cube, and part of a detecting component is placed outside the detected steel pipe concrete structure; the system comprises: the piezoelectric ultrasonic transducer comprises a piezoelectric element, a first piezoelectric ultrasonic transducer (50 kHz), a power amplification circuit, an internal small power supply (5V), a second piezoelectric ultrasonic transducer (100kHz) and a steel closed cube. The piezoelectric element consists of a piezoelectric ceramic piece, a steel sheet bearing the piezoelectric ceramic piece and a support plate used for fixing the steel sheet.

A first piezoelectric ultrasonic transducer (50 kHz) in the detection system is attached to the outer wall of the measured concrete-filled steel tube, and other devices are all arranged in the steel closed cube and are pre-embedded in the position, required to be measured, in the concrete-filled steel tube. All the parts in the steel closed cube are connected through electric leads; the power amplifying circuit is adhered to one side of the steel closed cube, which is opposite to the piezoelectric element; and the second piezoelectric ultrasonic transducer is adhered to the lower part in the steel closed cube.

Further, the first piezoelectric type ultrasonic transducer (50 kHz) provides vibration excitation to the steel sheet and can receive ultrasonic waves with a frequency near 50 kHz.

Further, the vibration of the steel sheet and the steel sheet can enable the piezoelectric ceramic plates glued on the steel sheet to vibrate together, so that periodic deformation is caused.

Furthermore, one end of the steel sheet is a free end, and the other end of the steel sheet is in rigid connection with the steel sheet restraint end through welding.

Furthermore, the internal small power supply (5V) supplies voltage to the power amplification circuit.

Furthermore, the power amplifying circuit can amplify the voltage generated by the piezoelectric ceramics to meet the threshold value of the piezoelectric ultrasonic transducer (100kHz) for emitting ultrasonic waves, and the power amplifying circuit is connected with the piezoelectric ceramics through an electric lead.

Further, the second piezoelectric ultrasonic transducer (100kHz) may generate a piezoelectric ultrasonic wave of 100kHz by using the amplified voltage.

The invention provides a piezoelectric ceramic self-generating and detecting method for detecting a steel pipe concrete structure, which utilizes the system to detect and comprises the following steps:

(1) the piezoelectric element, the power amplifying circuit and the second piezoelectric ultrasonic transducer are connected through electric leads and placed in the steel closed cube, and after the piezoelectric element supporting plate and the steel closed cube are welded and fixed, the steel closed cube is sealed. This sealing system will be referred to as a piezoelectric ceramic self-generating-detecting system hereinafter.

(2) Before the steel pipe concrete is poured and molded, the piezoelectric ceramic self-generating-detecting system is placed at a key position which needs to be detected in the future and is embedded in the steel pipe concrete, and the position of the steel closed cube can be fixed after the concrete is hardened and molded.

(3) After the steel pipe concrete structure is formed, when detection is needed, a detector holds the first piezoelectric ultrasonic transducer in a hand and clings to the outside of the steel pipe concrete embedded with the piezoelectric ceramic self-generating-detecting system, and the distance between the first piezoelectric ultrasonic transducer and the piezoelectric ceramic self-generating-detecting system cannot exceed 1 m;

(4) after all the detection devices are arranged at the target positions, a detector starts the first piezoelectric ultrasonic transducer, sends ultrasonic waves with the frequency of 50kHz to the piezoelectric ceramic self-generating-detection system, and can simultaneously receive ultrasonic signals fed back by the piezoelectric ceramic self-generating-detection system.

(5) And collecting a target signal, and withdrawing the first handheld piezoelectric ultrasonic transducer by the detection personnel.

(6) The ultrasonic signal of sending and receiving of the handheld 50kHz ultrasonic transducer of contrast testing personnel can realize the detection to concrete filled steel tube key position.

The invention has the beneficial effects that:

the detection system generates electricity through the deformation of the piezoelectric ceramics, and achieves the purpose of no need of external power supply; meanwhile, the piezoelectric ultrasonic transducer is utilized in the structure body, the ultrasonic wave with the specified frequency is emitted in the structure body by the ultrasonic wave to achieve the purpose of measurement, the energy dissipation of the ultrasonic wave in the ultrasonic rebound method is reduced, and the detection depth is improved.

Drawings

Fig. 1 is a schematic flow chart of the function implementation of the present invention.

Fig. 2 is a schematic view of a piezoelectric element.

Fig. 3 is a schematic diagram of a power amplifier circuit.

FIG. 4 is a schematic diagram of the application of the detection device in concrete filled steel tubes.

FIG. 5 is a schematic diagram showing the connection of various components inside the detection apparatus.

In the figure: the ultrasonic transducer comprises a piezoelectric element 1, a power amplifying circuit 2, a second piezoelectric ultrasonic transducer 3, a first piezoelectric ultrasonic transducer 4, a steel closed cube 5, a piezoelectric ceramic sheet 101, a steel sheet 102 and a support plate 103.

Detailed Description

The present invention is further illustrated by, but is not limited to, the following examples.

Example 1:

as shown in fig. 1 to 5, the piezoelectric ceramic self-generating-detecting system for detecting the steel pipe concrete structure is partially encapsulated in a steel closed cube, and part of detecting components are placed outside the detected steel pipe concrete structure; the system comprises: the piezoelectric ultrasonic transducer comprises a piezoelectric element, a first piezoelectric ultrasonic transducer 4 (50 kHz), a power amplification circuit 2, an internal small power supply (5V), a second piezoelectric ultrasonic transducer 3(100kHz) and a steel closed cube. The piezoelectric element is composed of a piezoelectric ceramic piece 101, a steel piece 102 bearing the piezoelectric ceramic piece, and a support plate 103 for fixing the steel piece.

A first piezoelectric ultrasonic transducer (50 kHz) in the detection system is attached to the outer wall of the measured concrete-filled steel tube, and other devices are all arranged in the steel closed cube and are pre-embedded in the position, required to be measured, in the concrete-filled steel tube. All the parts in the steel closed cube are connected through electric leads; the power amplifying circuit is adhered to one side of the steel closed cube, which is opposite to the piezoelectric element; and the second piezoelectric ultrasonic transducer is adhered to the lower part in the steel closed cube.

Further, the first piezoelectric type ultrasonic transducer (50 kHz) provides vibration excitation to the steel sheet and can receive ultrasonic waves with a frequency near 50 kHz.

Furthermore, the vibration of the steel sheet and the steel sheet can make the piezoelectric ceramic pieces attached to the steel sheet vibrate together to cause periodic deformation.

Furthermore, one end of the steel sheet is a free end, and the other end of the steel sheet is in rigid connection with the steel sheet restraint end through welding.

Furthermore, the small power supply (5V) of the power amplification circuit provides required voltage for power amplification.

Furthermore, the power amplifying circuit can amplify the voltage generated by the piezoelectric ceramics to meet the threshold value of the piezoelectric ultrasonic transducer (100kHz) for emitting ultrasonic waves, and the power amplifying circuit is connected with the piezoelectric ceramics through an electric lead.

Further, the second piezoelectric ultrasonic transducer (100kHz) may generate a piezoelectric ultrasonic wave of 100kHz by using the amplified voltage.

The invention provides a piezoelectric ceramic self-generating and detecting method for detecting a steel pipe concrete structure, which utilizes the system to detect and comprises the following steps:

(1) the piezoelectric element, the power amplifying circuit and the second piezoelectric ultrasonic transducer are connected through electric leads and placed in the steel closed cube, and after the piezoelectric element supporting plate and the steel closed cube are welded and fixed, the steel closed cube is sealed. This sealing system will be referred to as a piezoelectric ceramic self-generating-detecting system hereinafter.

(2) Before the steel pipe concrete is poured and molded, the piezoelectric ceramic self-generating-detecting system is placed at a key position which needs to be detected in the future and is embedded in the steel pipe concrete, and the position of the steel closed cube can be fixed after the concrete is hardened and molded.

(3) After the steel pipe concrete structure is formed, when detection is needed, a detector holds the first piezoelectric ultrasonic transducer in a hand and clings to the outside of the steel pipe concrete embedded with the piezoelectric ceramic self-generating-detecting system, and the distance between the first piezoelectric ultrasonic transducer and the piezoelectric ceramic self-generating-detecting system cannot exceed 1 m;

(4) after all the detection devices are arranged at the target positions, a detector starts the first piezoelectric ultrasonic transducer, sends ultrasonic waves with the frequency of 50kHz to the piezoelectric ceramic self-generating-detection system, and can simultaneously receive ultrasonic signals fed back by the piezoelectric ceramic self-generating-detection system.

(5) And collecting a target signal, and withdrawing the first handheld piezoelectric ultrasonic transducer by the detection personnel.

(6) The ultrasonic signal of sending and receiving of the handheld 50kHz ultrasonic transducer of contrast testing personnel can realize the detection to concrete filled steel tube key position.