Multi-peak-value regression estimation method for structural damages based on reverse focusing peak value

Abstract

The invention discloses a multi-peak-value regression estimation method for structural damages based on a reverse focusing peak value. The method comprises the following steps: carrying out a sweep frequency test on an undamaged structure to be detected by adopting an initiative stress wave detection mode to obtain a structure amplitude-frequency response curve; selecting a plurality of wave crest frequencies from the structure amplitude-frequency response curve as detection signal central frequencies; carrying out damage detection on the structure by combination of a time reversal technology and the initiative stress wave detection mode so as to obtain focusing peak values of different central frequency time reversal focusing signals in different damage states; carrying out multi-variant linear regression analysis by taking different central frequency focusing peak values as independent variables, taking the different central frequency focusing peak values measured in the different damage states as independent variable regression samples, and taking the damage states as dependent variables to obtain a regression equation of the damage states. Under the condition that testing conditions are not changed, the method can be used for estimating the current structural damage state by the plurality of different central frequency focusing peak values measured in the certain damage state according to the regression equation.

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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