Laser ultrasonic three-dimensional localization and quantitative detection method for multiple defects in material

Abstract

The invention discloses a laser ultrasonic three-dimensional localization and quantitative detection method for multiple defects in a material. Under two-dimensional scanning conditions, the internaldefects are subjected to localization detection at crossing points of three propagation direction paths by using an excited oblique transmission ultrasonic bulk wave, a bottom incident ultrasonic transverse wave and a bottom reflected transverse wave, and the internal defects are quantitatively detected using the oblique transmission ultrasound body wave attenuation or wave-front delay. The amplitude of the oblique transmission ultrasonic body wave and the bottom reflected transverse wave after defect attenuation and transmission is much larger than the amplitude of the reflected or diffractedwave of the defects, which overcomes the problems of weak ultrasonic signals and low signal-to-noise ratio when detecting sub-millimeter micro defects. The oblique transmission ultrasonic body waves,bottom incident ultrasonic transverse waves and bottom reflected transverse waves respectively interact with the defects from three directions, the internal defects can be accurately located based onthe three ultrasonic intersections of the attenuation position, and accurate quantitative detection of multiple defects can be realized, which is suitable for sub-millimeter-level multi-defect localization and quantitative detection of detection materials.

Description

technical field [0001] The invention relates to the technical field of non-destructive testing of materials, in particular to a laser ultrasonic three-dimensional positioning and quantitative testing method for multiple defects inside a material. Background technique [0002] In many fields such as engineering construction, the existence of internal defects will seriously affect the quality and performance of materials. Therefore, timely and accurate nondestructive testing of internal defects of materials is of great significance. With the development of industrial automation and intelligence, the future demand for non-destructive testing methods is to have non-contact, online, high-precision and high-efficiency testing capabilities. As an emerging nondestructive testing method, laser ultrasonic technology has the advantages of non-contact, no radiation, fast detection speed, and high spatial resolution, and has broad application prospects in the detection of internal defect...

AI Technical Summary

Problems solved by technology

[0010] The technical problem to be solved by the present invention is: for submillimeter small defects, especially when there are multiple defects inside the material, when the traditional pulse reflection body wave method, body wave transmission method or diffraction time-of-flight method is used for detection, the existence detection The problem of insufficient sensitivity and accuracy, the present invention provides a laser ultrasonic three-dimensional positioning and quantitative detection method for multiple defects in the material to solve the above problems

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