A rapid non-destructive testing method for large-scale composite materials and their sandwich structures

Abstract

The present invention is a fast non-destructive detection method for large-scale composite materials, which is characterized in that it includes: obtaining a fast sparse characterization vector of a non-defective reference signal sample set according to random sampling of standard parts; fast sparse characterization, the sparse characterization of the reference signal and the sampling signal are equal Parallel denoising and sparse representation of signal singularity measurement based on wavelet domain modulus maxima, feature clustering using nonlinear support vector machine, adaptive observation model of correlation entropy and normalization of Sigmoid function; using correlation entropy The maskless compressed sensing (CS) topological distribution optimization strategy of the adaptive model, fast characterization results and correlation entropy The adaptive model judges the homogeneity and heterogeneity of the signal through weighting, combined with the block random form of the structured idea, Under the framework of CS theory, a structured and easy-to-storage measurement matrix is ​​designed to provide effective data for reconstruction after rapid detection. The method is closely related to the parameters of the detection object, the realization method is simple and easy, and the engineering practicability is strong.

Description

technical field [0001] The invention belongs to the field of non-destructive testing of composite materials and their sandwich structures, and in particular relates to a rapid non-destructive testing method for large-sized composite materials and their sandwich structures. Background technique [0002] The excellent properties of composite materials and their sandwich structures in mechanics, processing and molding make them highly respected in the field of aerospace and become an indispensable and important component of key components such as aviation, aerospace, and radio astronomy. Therefore, accurate non-destructive evaluation of its defects and damage is crucial. However, compared with metal structures, on the one hand, due to the complex nature of composite materials, the causes of fatigue and fracture are more difficult to understand than metal structures, and the detection of tightly stacked or complex defects or damage targets in sandwich structures has always been ...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a fast terahertz nondestructive testing method for large-scale composite materials and their sandwich structures. Feature sparsification, adaptive identification, compressed sampling data volume and acquisition time to achieve fast non-destructive detection

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