Online Damage Imaging Method Based on Cross Array and Wavenumber Scanning Filter

Abstract

The invention discloses an on-line damage imaging method based on a cross array and a wave number scanning filter, and belongs to the technical field of engineering structure health monitoring. The method includes the steps that damage scattered signals in the structure are collected in an on-line mode through the cross array first; then wave number-time images of the two linear array damage scattered signals in the cross array are obtained through the wave number scanning filter, so that the wave numbers and the arriving moments of the two linear array damage scattered signals are obtained; at last, on-line positioning of 0-360 degrees is conducted on damage through the wave numbers and the arriving moments of the two linear array damage scattered signals according to the wave number projection relationship of Lamb waves, and thus damage imaging is achieved under the condition that the wave number of the Lamb waves cannot be obtained accurately. The method does not need to rely on the wave number of the Lamb waves in the damage imaging process, and the influence on damage positioning results by structure material parameters is restrained; moreover, angle dead zones are avoided, and therefore the application of a space-wave number filter damage imaging method in the field of engineering structure health monitoring can be better promoted.

Description

technical field [0001] The invention relates to an online damage imaging method based on a cross array and a wavenumber scanning filter, and belongs to the technical field of engineering structure health monitoring. Background technique [0002] Composite materials have excellent properties such as high specific strength, high specific stiffness, and high specific modulus, and are widely used in aviation, aerospace and other fields. During the complex and changeable service process of composite material aeronautical structures, it is easy to suffer damage caused by sand, hail, bird strikes, collisions, etc., causing damage inside the structure, damaging the performance and integrity of structural parts, and weakening the structure. The strength of the structural parts is seriously threatened, which seriously threatens the safety of subsequent flights. The structural health monitoring method based on Lamb waves has the advantages of high damage monitoring sensitivity, large ...

AI Technical Summary

Problems solved by technology

This method relies on the wavenumber of the Lamb wave in the space-wavenumber filtering process. When the material parameters of the structure are unknown or in a relatively complex structure, the wavenumber of the Lamb wave is difficult to obtain accurately, which causes damage to the space-wavenumber filter damage imaging method. Positioning accuracy is severely reduced

Moreover, this method also has a blind spot for angle monitoring

These have severely limited the application of space-wavenumber filter damage imaging methods in health monitoring of composite materials.

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