A method for structural health monitoring of lamb wave plates based on synchronous compression wavelet transform

Abstract

The invention discloses a Lamb wave plate structure health monitoring method based on synchronous compression wavelet transform. The method includes the following steps: transmitting a plurality of excitation signals to the plate structure and receiving the returned response signals; transforming the response signals to obtain transformation coefficients ; Calculate the peak arrival time of the signal wave in the response signal through the transformation coefficient; calculate the wave speed of the response signal according to the peak arrival time; draw the frequency-velocity characteristic curve of the panel structure through the wave speed; judge the health state of the panel structure according to the frequency-velocity characteristic curve , the invention improves the time-frequency resolution through synchronous compression wavelet transform, analyzes the dispersion characteristics of Lamb waves, and judges the health state of the board structure through comparison, gets rid of the dependence on the difference signal, and performs time-frequency analysis on the response signal itself, which solves the problem. Compared with the traditional method, the time-varying conditions and multi-mode effects have better judgment ability for small damage, and can reflect more changes in the structure itself.

Description

technical field [0001] The invention relates to the field of on-line Lamb wave damage monitoring of engineering structures, in particular to a Lamb wave plate structure health monitoring method based on synchronous compression wavelet transform. Background technique: [0002] Engineering structures are often subjected to huge stress in use, and work in harsh environments, and it is easy to cause minor damage during long-term use. If these minor damages are not controlled in time, they will gradually evolve into serious damages, which will eventually affect the normal use of the structure and endanger personal and property safety. [0003] Structural health monitoring is an effective method to obtain and process data from structures in operational state to assess the durability, damage and other states of structures. It combines non-destructive testing and structural characteristic analysis to diagnose whether there is damage in the structure, determine the location of damag...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a Lamb wave plate structure health monitoring method based on synchronous compression wavelet transform, to solve the defect that the existing technology cannot accurately extract the characteristics of the response signal

Images