基于振型差小波变换的结构损伤检测方法

The Structure Damage Identification Based on Wavelet Transform of Vibration Mode Difference

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。在位移模态振型的基础上,提出了一种基于小波变换的结构损伤检测方法。将损伤前后结构的位移模态振型差作为原始信号进行小尺度小波变换,通过损伤前后位移模态振型差小波变换系数的变化,可判定损伤存在,确定损伤位置。并通过悬臂梁和海洋平台的数值模拟对该方法进行了验证。

The wavelet transform has an ability to present the local characterics of signal in both frequency and time domain. It can zoom in and recognize the signal abrupt changes of structural responses under different scales. An analysis method of structural damage identification is presented based on. the wavelet transform for the structural vibration displacement mode difference between the intact structure and the damaged structure. The abrupt change of wavelet coefficients indicates that there is some damage occures. The present method is validated through a cantilever beam and a offshore platform.