基于曲率模态和小波变换的结构损伤位置识别

Damage location identification of structures based on curvature mode and wavelet transform

小波变换具有在时域和频域内表征信号局部特性的能力,能够在不同尺度下对结构响应中的突变信号进行放大和识别。在结构曲率模态基础上,本文提出了一种基于小波变换的结构损伤检测和定位方法。利用双正交小波函数对损伤前后结构的曲率模态进行小波变换,用损伤前后小波变换系数残差建立了结构损伤指标,通过小波变换系数残差的分布统计情况判定损伤的存在并确定其位置。应用简支梁数值模拟结果对该方法进行了验证。

The wavelet tranform has an ability to present the local properties of signal in both frequency and time domain. It can zoom up and recognize the signal mutation of structural responses under different scales. Based on mode curvature, a damage location identification method of structures is presented by using the residuals of wavelet transform coefficients. The structural mode curvature curves before and after damage are transformed by the biorthogonal wavelets. The structural damage index is then defined with the residuals of wavelet transform coefficients before and after damage. The distribution of structural damage index is used to determine the location of damage in the sense of statistics. The method has been verified by the numerical simulation of simply supported beams with different damage scenarios.