Multi-peak regression assessment method for structural damage based on time defocused peaks

Abstract

The invention discloses a multi-peak regression evaluation method for structural damage based on time inverse focusing peaks. The method adopts the active stress wave detection mode to perform frequency sweep test on the non-destructive structure under test, and obtains the amplitude-frequency response curve of the structure; from the amplitude-frequency response of the structure Multiple peak frequencies are selected in the curve as the center frequency of the detection signal; time inversion technology combined with active stress wave detection mode is used to detect the damage of the structure, and the focus peaks of the time inversion focus signal of different center frequencies in different damage states are obtained; Focused peaks of different center frequencies were used as independent variables, and the focused peaks of different center frequencies measured under different damage states were used as independent variable regression samples, and the damage state was used as the dependent variable to conduct multiple linear regression analysis to obtain the regression equation of damage state. Under the condition that the test conditions remain unchanged, according to the regression equation, the above method can evaluate the current structural damage state from multiple focused peaks of different center frequencies measured in a certain damage state.

Description

technical field [0001] The invention relates to the field of testing and measurement technology and structural health monitoring, in particular to a multi-peak regression evaluation method for structural damage based on time defocusing peaks. Background technique [0002] After entering the 21st century, a new type of structural damage detection technology based on the principle of stress wave detection has become more and more favored by researchers for its detection advantage of using stress wave propagation. The stress wave propagation detection method not only overcomes the complex medium penetration problem that has plagued other damage detection methods for a long time, but also is suitable for online detection of long-distance large structures, and has gradually developed into a research hotspot in the field of structural health monitoring in recent years. As an important detection mode in the stress wave propagation detection technology, active stress wave has been w...

AI Technical Summary

Problems solved by technology

However, when using the frequency sweep test results to obtain the amplitude-frequency response curve of the structure, it is necessary to perform discrete Fourier transform on the frequency-sweep receiving signal and the frequency-sweep excitation signal in the time domain to obtain the amplitude-frequency characteristic expression, and the received signal The amplitude-frequency response curve of the structure can only be obtained by dividing the amplitude-frequency characteristic expression and the amplitude-frequency characteristic expression of the excitation signal. The calculation process is complicated and the calculation amount is large.

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