Lamb wave-based autonomous damage identification imaging method

Abstract

The invention relates to a Lamb wave-based autonomous damage identification imaging method in the technical field of detection of mechanical structures, which comprises the following steps of: constructing a sensing network, and correcting time reversal-based damage index DI of each sensing path in the sensing network; then setting 45% of the maximum value in all the corrected damage indexes of all the sensing paths as a threshold, and using the threshold to judge the degree of influences on the sensing paths caused by damages; and finally carrying out weighted distribution treatment on the damage indexes of all the sensing paths, and further obtaining the probability value that the damages emerge at a coordinate point (x, y). By using the method, the flight time for extracting wave signals scattered by defects can be avoided, and the shortcoming of depending on reference signals can be overcome. Not only can the requirements on real-time property and on-line property be satisfied, but also the multiple damages can be accurately identified and positioned, and the autonomous non-destructive testing of a plate-shell structure can be further realized, thus the method has very important practical value in aerospace, buildings and other fields.

Description

technical field [0001] The invention relates to a method in the technical field of mechanical structure detection, in particular to an autonomous damage recognition imaging method based on Lamb waves. Background technique [0002] Lamb waves are guided waves propagating in plate and shell structures. In the past two decades, the method of using transducers to excite and collect Lamb wave signals has been widely used in the field of nondestructive testing of large plate and shell structures. The traditional damage identification method based on Lamb waves usually needs to collect signals on the structure in advance when the structure is free of defects, and use the collected signals as a reference signal; then collect signals on the current structure, and use the collected signals as a detection signal. Signal. Comparing the reference signal and the detection signal to extract the time-of-flight (ToF) of the wave signal scattered by the defect, and using the triangulation al...

AI Technical Summary

Problems solved by technology

When the environmental factors of the structure change, the essential characteristics of the wave signal propagating in the structure will change, and this change will confuse the characteristic change of the wave signal caused by the defect, greatly reducing the accuracy of damage identification and location , unable to meet the requirements of real-time and online

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