基于曲率模态和小波变换的简支梁桥损伤识别方法

An Identification Method of Simple Beam Bridge's Damages 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.本文在曲率模态基础上,提出了一种基于小波变换的梁式结构损伤识别方法.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,通过小波变换系数的变化和分布情况建立了结构损伤指标,可判定损伤存在,确定损伤位置和估计损伤程度.并通过一简支梁桥中T形截面梁的数值模拟对该方法进行了验证.

The wavelet transform may present the local properties of signal in time-frequency domain, and can zoom up and recognize the mutation signal of structural response under different scales. Based on curvature mode and wavelet transform, this paper presents a recognition method for structural damages. The structural curvature mode curves before and after damage are transformed in biorthogonal wavelets. The structural damage index is presented with the change and distribution of wavelet transform coefficients. It may be used to determine occurance, location and degree of damage. And the method has been verified by the numerical simulation of a simple beam bridge. The simulation results show that the method is effective.