A damage detection method for plate-shaped structures

Abstract

The invention relates to a damage detection method of a plate structure, which comprises the following steps: S1: a piezoelectric transducer array is arranged on the plate structure; S2: establishing a reference database; S3: collecting current signals of the plate structure to be tested and the current temperature; S4: Calculate the difference signal, the difference signal = the current baseline signal in the benchmark database - the current signal; S5: Calculate the damage index based on the difference signal and the current baseline signal, and if the damage index exceeds the preset threshold, it is judged to be tested If the plate structure is damaged, if the damage index does not exceed the preset threshold, it is judged that the plate structure to be tested is not damaged. The damage detection method adopts a temperature compensation method, and in the damage detection process of the plate-shaped structure through the piezoelectric transducer, the influence caused by large temperature changes is weakened, the detection accuracy is improved, and potential safety hazards are avoided.

Description

technical field [0001] The invention relates to the technical field of structure detection, in particular to a damage detection method for a rail vehicle plate structure. Background technique [0002] At present, piezoelectric intelligent detection technology, as a kind of structural health detection technology, can carry out regional detection, is easy to integrate with structures, and is widely used in damage detection of composite materials and metal structures. In the existing technology, in the method of detecting structural damage through piezoelectric transducers, since the detection environment is mostly indoors and the environmental conditions are relatively stable, the influence of temperature on the detection results is not considered, but the change of temperature will make the structure The phenomenon of thermal expansion and contraction occurs, which affects the wave propagation in the structure to be detected, and then affects the accuracy of structural damage...

AI Technical Summary

Problems solved by technology

In the existing technology, in the method of detecting structural damage through piezoelectric transducers, since the detection environment is mostly indoors and the environmental conditions are relatively stable, the influence of temperature on the detection results is not considered, but the change of temperature will make the structure The phenomenon of thermal expansion and contraction occurs, which affects the propagation of waves in the structure to be detected, which in turn affects the accuracy of structural damage detection

[0003] When performing damage detection on key parts such as the EMU car body, due to the change of the external environment temperature or the temperature difference between the transformer in the working state and the transformer in the stopped state when the train is running, the key parts located around it The temperature of the structure also rises accordingly. At this time, if the damage detection of these key structures is carried out, the piezoelectric transducer is used for detection but the temperature factor is not considered, the detection accuracy will be affected, and there will be a large safety hazard.

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