Reference-free damage identification method for composite material plate-shaped structure

Abstract

The invention relates to a reference-free damage identification method for a composite material plate-shaped structure, belonging to the field of structure health monitoring. The method comprises the following steps of: uniformly distributing a sensor array formed by piezoelectric elements on the composite material plate-shaped structure; sequentially exciting each piezoelectric element through a low-frequency and wide-wave signal and collecting corresponding signals of the residual piezoelectric elements when each piezoelectric element is excited; then calculating a damage index on each exciting sensing path according to a signal difference on a similar exciting sensing path; and finally, imaging damages by utilizing a possibility imaging method. According to the reference-free damage identification method disclosed by the invention, online damage identification and imaging of the composite material plate-shaped structure can be conveniently realized, so as to guarantee the safety of the composite material structure in a use process; and the accuracy and the stability are high.

Description

technical field [0001] The invention relates to a damage identification method, in particular to a sensor network-based composite material plate structure no-reference damage identification method, belonging to the technical field of structural health detection. Background technique [0002] The health monitoring method of aeronautical structures with reference signals has been extensively studied. However, due to the great influence of environmental factors such as temperature and noise on Lamb waves, the propagation characteristics of Lamb waves in the working environment are often very different from the measured reference signals. , which poses a challenge to the effectiveness and accuracy of damage identification. Some scholars use correction or probability methods to solve this problem: the correction method considers the influence of the environment, first corrects the reference signal, and then compares it with the actual measurement signal to extract the damage inde...

AI Technical Summary

Problems solved by technology

However, this method is complex to operate and difficult to implement online

The no-reference damage identification method based on the mode conversion phenomenon of Lamb waves at the damage site believes that when the calculated conversion mode (including noise) is greater than the maximum value of the statistical noise energy, there is damage in the structure; however, this method only roughly knows There is damage in the structure, and the location and degree of damage cannot be further identified

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