A damage detection method and system for a multilayer composite material

Abstract

The invention discloses a damage detection method and system for a multilayer composite material. The method comprises the following steps that: the material parameters of a composite material to be detected are acquired; the ultrasonic reflection signals and ultrasonic transmission signals of the composite material to be detected are acquired, wherein the ultrasonic reflection signals are signals collected by the upper probe of an ultrasonic detection instrument, and the ultrasonic transmission signals are signals collected by the lower probe of the ultrasonic detection instrument; matching pursuit decomposing is performed on the ultrasonic reflection signals and the ultrasonic transmission signals through an improved matching pursuit method, so that the characteristic information of the ultrasonic reflection signals and the ultrasonic transmission signals are obtained; a BP neural network model is adopted to obtain the damage layer parameters of the composite material to be detected according to the material parameters of the composite material to be detected, and the characteristic information of the ultrasonic reflection signals and ultrasonic transmission signals; and the depth and thickness of the damage layer of the composite material to be detected are determined according to the damage layer parameters. With the damage detection method and system for the multilayer composite material of the invention adopted, the efficiency and precision of damage detection can be improved.

Description

technical field [0001] The invention relates to the field of composite material detection, in particular to a damage detection method and system for multilayer composite materials. Background technique [0002] In recent years, with the wide application of composite materials, in order to ensure the safety and reliability of materials, nondestructive testing methods for composite materials have gradually received widespread attention. Different from traditional isotropic homogeneous metal materials, composite materials have the concept of "layer" due to the actual work requirements and the limitation of preparation conditions. However, in the preparation and use of composite materials, around the characteristics of the "layer" structure, various defects inevitably appear: intra-layer defects such as material denaturation, uneven thickness, etc., and inter-layer defects such as debonding. These problems may make the material strength less than expected or cause local instabi...

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Problems solved by technology

However, in the preparation and use of composite materials, around the characteristics of the "layer" structure, various defects inevitably appear: intra-layer defects such as material denaturation, uneven thickness, etc., inter-layer defects such as debonding, etc.

Traditionally, the detection of intralayer and interlayer defects of composite materials mostly uses the ultrasonic pulse reflection method. This method can obtain information such as the location, depth, and even size of defect damage to a certain extent, but the efficiency is low and the sensitivity is poor, especially for The ability to judge multi-layer damage along the depth direction is relatively limited

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