基于小波能量分布向量的结构损伤识别

利用小波变换时-频局部化性能,提出了基于小波能量分布向量的结构损伤识别方法。首先建立无损结构响应信号小波能量分布的总体向量;其次,将实测动力响应信号分解为小波包组分,计算其小波能量分布向量(样本向量);通过样本向量和总体向量之间的马氏距离识别损伤。该方法仅利用单测点结构响应数据进行损伤识别,实验方便,计算简单,并通过钢梁试验对损伤识别方法进行了试验验证,识别结果表明小波能量分布向量是一个比较好的结构损伤指标。

Structural damage identification based on wavelet energy distribution vectors

In terms of a unique feature of wavelet transform in analyzing local signals with an arbitrary resolution in the timefrequency domain,a structural damage identification method based on the wavelet energy distribution vector is presented in this paper.Firstly,the collectivity vectors that express the wavelet energy distribution of response signal of intact structure are established.Secondly,the measured dynamic response signals are decomposed into the wavelet packet components and their wavelet energy distribution vectors are calculated,which are called the sample vectors.The damage is identified by calculating the Mahalanobis distances between sample vectors and collectivity vectors.This method identifies the damage only applying to data of single measuring point.The proposed damage identification method and index have been verified with a tested model beam.It is illuminated that the wavelet energy distribution vector is a sensitive and good damage index.