Method for acquiring ultrasonic-acoustic emission detection signal of composite material

Abstract

The invention relates to a method for acquiring an ultrasonic-acoustic emission detection signal of a composite material. An ultrasonic-acoustic emission transducer forms an ultrasonic-acoustic emission composite acoustic beam by adopting a zero approaching distance layout of a left acoustic beam and a right acoustic beam, and directly receives an acoustic emission signal in a part of the detected composite material; two acoustic beam forming modes, namely a circular ring acoustic beam forming mode and a semicircular ring acoustic beam forming mode, are adopted, and symmetric and asymmetric modes are adopted, so that the frequency range is 1-10MHz; an excitation unit supplies an ultrasonic-acoustic emission excitation signal; a receiving unit consists of a nonlinear attenuator, an input level, an amplification level and the like; a gain adjustment range is 1-20dB; the bandwidths are 50MHz and 100MHz. The time domain characteristic and the frequency domain quality of the ultrasonic-acoustic emission signal are obviously improved, so that a defect signal judgment rule is very clear, and the detection resolution is obviously improved; the ultrasonic-acoustic emission detection capability of the composite material and the detection sensitivity are greatly improved; the method can be used for ultrasonic-acoustic emission signal treatment analysis of different composite materials.

Description

technical field [0001] The invention belongs to the non-destructive detection technology, and relates to a method for obtaining ultrasonic-acoustic emission detection signals of composite materials in the fields of aviation, aerospace, weapons, ships, transportation, metallurgy, steel, construction and the like. Background technique [0002] The current ultrasonic-acoustic emission detection signal acquisition method is as follows: figure 1 As shown, the ultrasonic transducer 3 is used to obtain the left sound beam 3A, the right sound beam 3B and the connecting mechanism 3C, wherein a certain distance is separated between the left sound beam 3A and the right sound beam 3B, and its main deficiency is: ultrasonic-acoustic After the transmission signal 7 propagates over a long distance, waveform transformation and multiple transmissions / refractions will occur, so that the law of the ultrasonic-acoustic emission signal becomes complicated, and interference signals and acoustic e...

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Problems solved by technology

[0002] The current ultrasonic-acoustic emission detection signal acquisition method is as follows: figure 1 As shown, the ultrasonic transducer 3 is used to obtain the left sound beam 3A, the right sound beam 3B and the connecting mechanism 3C, wherein a certain distance is separated between the left sound beam 3A and the right sound beam 3B, and its main deficiency is: ultrasonic-acoustic After the transmission signal 7 propagates over a long distance, waveform transformation and multiple transmissions / refractions will occur, so that the law of the ultrasonic-acoustic emission signal becomes complicated, and interference signals and acoustic emission pulse signal distortion will be introduced at the receiving end, resulting in ultrasonic-acoustic emission. Acoustic emission signal interpretation is difficult, time-domain characteristics are poor, defect discrimination is difficult, it is difficult to accurately locate defects, quantitative and qualitative analysis, and detection resolution is low

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