A composite material acoustic detection sensor and detection method

Abstract

The invention discloses an acoustic detection sensor and a detection method for composite materials. The acoustic detection sensor comprises an excitation piezoelectric chip, a vibration rod, a capacitance microphone and a contact. The acoustic detection sensor and the detection method have the advantages that a receiving piezoelectric chip is replaced with the capacitance microphone, accordingly,the problem that existing receiving piezoelectric chips need to be matched with existing excitation piezoelectric chips can be solved, the acoustic detection sensor is easy to manufacture, and the detection sensitivity can be improved; abundant harmonic components can be obtained, accordingly, frequency spectrum analysis can be facilitated, the acoustic detection sensor and the detection method are favorable for detecting discontinuity information of the materials, and further analytical processing can be facilitated.

Description

technical field [0001] The invention relates to a non-destructive detection device and method, in particular to a composite material acoustic detection sensor and detection method. Background technique [0002] Adhesive composite materials have the advantages of light weight, high strength, convenient processing and molding, excellent elasticity, temperature resistance and corrosion resistance, and have been widely used in aerospace, automobile, chemical and other manufacturing fields. For example, the fuselage of modern aerospace vehicles uses a large number of bonded composite structural parts. The bonding quality of cemented composite structural parts is extremely important to its safe operation. One of the commonly used detection methods for the bonding quality of cemented composite structural parts is mechanical impedance detection. The existing mechanical impedance detection usually has a detection frequency of 2kHz~10kHz. Among them, it belongs to the high-frequency ...

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Problems solved by technology

The bonding quality of cemented composite structural parts is extremely important to its safe operation. One of the commonly used detection methods for the bonding quality of cemented composite structural parts is mechanical impedance detection. The existing mechanical impedance detection usually has a detection frequency of 2kHz~10kHz. Among them, it belongs to the high-frequency range, and the detection mode is similar to the eddy current impedance diagram. The mechanical impedance sensor used in it (see "Nondestructive Testing Technology of Modern Composite Materials" (Shen Jianzhong, Lin Junming edited), page 71, Pic 4-1 3), two piezoelectric chips are usually used, one piezoelectric chip is the excitation piezoelectric chip, which is used to excite the sensor to generate mechanical vibration, and the other piezoelectric chip is the receiving piezoelectric chip, which is used to receive the pressure of the cemented composite material to be tested. Due to the inherent selective characteristics of the piezoelectric chip, the vibration signal generated by the vibration cannot obtain a broadband vibration detection signal, and it is necessary to ensure that the receiving piezoelectric chip is paired with the exciting piezoelectric chip to obtain a better detection effect during design and manufacture. Limited to the manufacturing process, the processing is difficult, the receiving piezoelectric chip and the excitation piezoelectric chip are difficult to match, and the detection effect is not ideal

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