Defect positioning method for condensed laser sensor array based Lamb corrugated plate structure

Abstract

A defect positioning method for a condensed laser sensor array based Lamb corrugated plate structure belongs to the field of laser ultrasonic non-destructive testing. Multiple sensor array elements are distributed at a center position of a metal plat structure to form an n* n condensed array for detecting defects of a whole plate structure. Single sensor array elements excite the rest sensor array elements to receive, thus collecting (see the description) groups of data. Continuous wavelet transform is performed on collected data to extract signals nearby specific frequencies. Then the extracted signals are subjected to dispersion compensating to remove the dispersion phenomenon of the signals, which is favorable for accurately recognizing the defects. The signals are subjected to total focusing imaging and symbol coherent factor imaging, and imaging results of the two are subjected to image fusing, thus accurately positioning the defects.

Description

technical field [0001] The invention provides a defect location method based on a Lamb wave plate structure of a dense laser sensor array, which belongs to the field of laser ultrasonic nondestructive testing. Background technique [0002] With the rapid development of modern industry, sheet metal structures have been widely used in engineering fields such as petrochemical, aerospace and marine transportation. Tank bodies, pressure vessel shells, aircraft wings, and ship hulls are all large sheet metal structures. Among them, storage tanks and pressure vessels are important infrastructures in petrochemical and other industries. However, these metal plate structures generally work under harsh conditions during service and are mostly in a load-bearing state. They are vulnerable to impact, corrosion, and fatigue, resulting in different types of defects. Once these defects expand, they will easily lead to a significant decline in structural safety and reliability. The remainin...

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Problems solved by technology

However, these metal plate structures generally work under harsh conditions during service and are mostly in a load-bearing state. They are vulnerable to impact, corrosion, and fatigue, resulting in different types of defects. Once these defects expand, they will easily lead to a significant decline in structural safety and reliability. Remaining useful life is shortened and the whole structure fails, even with catastrophic consequences

These metal plate structures generally have a large area, which brings great difficulties to large-scale nondestructive testing.

Existing conventional non-destructive testing methods are still unable to meet this testing requirement

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