Nondestructive testing method for sandwich composite material based on two-dimensional continuous wavelet transformation
A composite material and wavelet transform technology, applied in the analysis of materials, material analysis using sound waves/ultrasonic waves/infrasonic waves, measuring devices, etc.
Pending Publication Date: 2021-11-26
ZHENGZHOU UNIVERSITY OF LIGHT INDUSTRY
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[0005] Aiming at the deficiencies of the prior art, the present invention provides a non-destructive testing method for sandwich composite materials based on two-dimensional continuous wavelet transform, so as to make up for the defect that there is currently no desoldering damage analysis method for this type of sandwich composite material
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[0081] A non-destructive testing method for sandwich composite materials based on two-dimensional continuous wavelet transform, the non-destructive testing method comprises the following steps:
[0082] S1. Use the commercial finite element software ANSYS to establish a three-dimensional model of the sandwich composite material, and establish a finite element analysis of the model to obtain the optimal mode shape for damage analysis;
[0083] Assuming that the sandwich composite material is a sandwich corrugated board, the size of the sandwich corrugated board is 300mm×150mm×20mm, and the thickness of the panel is 1.5mm. The elastic modulus of the material used is E=206GPa, Poisson’s ratio u=0.3, density ρ=7860kg / m 3 , the element type is shell element, the upper and lower panels of the structure are divided into 60×120 elements, each element size is 2.5mm×2.5mm, the trapezoidal sandwich corrugated plate finite element model ( figure 2 ) are obtained from 7381 nodes of these...
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Abstract
The invention relates to the technical field of nondestructive testing of materials, in particular to a nondestructive testing method for a sandwich composite material based on two-dimensional continuous wavelet transformation. The detection method comprises the following steps that firstly, the modal shape curvature of a fourth-order modal shape, obtained through numerical analysis, of a structure is obtained through a formula; then the modal shape curvature is processed through the two-dimensional continuous wavelet transformation, so a wavelet coefficient about the modal shape curvature is obtained; and a damage identification index is established through the obtained wavelet coefficient. According to the nondestructive testing method for the sandwich composite material based on the two-dimensional continuous wavelet transformation, the modal shape curvature can be used as a spatial domain signal through wavelet analysis, singular point detection is carried out, so structural damage signals can be well extracted, a detection result shows that the middle position of the damage also has an obvious bulge, and the approximate position, the number and the approximate length of the damage can be effectively detected.
Description
technical field [0001] The invention relates to the technical field of non-destructive testing of materials, in particular to a non-destructive testing method for sandwich composite materials based on two-dimensional continuous wavelet transform. Background technique [0002] In recent years, with the development of material preparation and machining technologies, new composite materials with multi-purpose, light weight, low cost and excellent mechanical properties have been more and more used in various engineering fields, especially food packaging, light Machinery and other fields. [0003] Sandwich corrugated board, as a new type of composite material, is a composite material formed by welding the upper and lower panels and the middle corrugated core. At present, some scholars at home and abroad have studied this structure. At present, the research on this kind of sandwich corrugated plate is mostly focused on its static properties and mechanical properties after being i...
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IPC IPC(8): G01N29/04G01N29/44
CPCG01N29/04G01N29/4418G01N29/4472G01N2291/0231
Inventor 田淑侠李广棵陈振茂房占鹏巩晓赟杜文辽张德海
Owner ZHENGZHOU UNIVERSITY OF LIGHT INDUSTRY