Method for determining ultrasonic-acoustic emission detection defect depth of composite material

Abstract

The invention belongs to a non-destructive testing technology, and relates to a method for determining ultrasonic-acoustic emission detection defect depth of a composite material in the fields of aviation, spaceflight, weapons, ships, metallurgy, steel, traffic, building and the like. The method comprises the following steps: firstly, preparing a thickness calibration test block; secondly, obtaining a thickness reference signal of the thickness calibration test block and checking the defect depth; finally, determining the detected defect depth. According to the method disclosed by the invention, by utilizing a time domain relation between n emission behavior of sound waves and defects in a detected material or the structure and adopting time-domain pulse characteristics of improved ultrasonic-acoustic emission signals, the ultrasonic-acoustic emission longitudinal resolution can be increased, and the defect depth can be more favorably and accurately detected; the method can be more easily realized, is very fast and easy to operate and master, and has better engineering detection and application practicability; the method is more beneficial for quality control of detection results,so that popularization and application of an ultrasonic-acoustic emission method can be more facilitated, and the ultrasonic-acoustic emission method can more favorably play a role in engineering.

Description

technical field [0001] The invention belongs to non-destructive testing technology, and relates to a method for determining the depth of defects detected by ultrasonic-acoustic emission of composite materials in the fields of aviation, aerospace, weapons, ships, metallurgy, steel, transportation, construction and the like. Background technique [0002] Because the ultrasonic-acoustic emission signal source comes from the inside of the detected part or structure, it is not sensitive to the orientation of defects and has stronger penetrating ability, so it is widely used in aerospace, weapons, electronics, ships, metallurgy, petrochemical oil, transportation, construction There are many unique applications in such fields, one of the important applications is the defect detection for composite materials and metal material structures. [0003] The obvious shortcoming of the current ultrasonic-acoustic emission detection method is that the horizontal distance from the detected de...

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Problems solved by technology

[0003] The obvious shortcoming of the current ultrasonic-acoustic emission detection method is that the horizontal distance from the detected defect to the receiving transducer can be roughly determined by using the transducer to receive the acoustic emission signal from the defect, but it is difficult to determine the depth of the detected defect. Moreover, due to the poor time-domain pulse characteristics and resolution of the traditional ultrasonic-acoustic emission detection signal, it is difficult to accurately determine the depth of the detected defect, let alone determine the detected defect, such as delamination defects, in the composite material structure. Therefore, it is difficult to meet the requirements for accurate depth determination of detected defects in the field of composite material detection, which limits the application of ultrasonic-acoustic emission method detection. However, the determination of the detected defect depth using the traditional ultrasonic thickness measurement principle requires Use a test block of known thickness to measure the sound velocity first, which is easy to introduce the deviation caused by the sound velocity measurement

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