基于小波变换的钢桁梁桥损伤识别数值分析

Numerical Analysis on Damage Identification of Steel Truss Bridge Based on Wavelet Transform

为了验证基于曲率模态理论和小波变换相结合的损伤识别方法在桥梁结构监测中的适用性,采用SAP2000软件创建钢桁梁桥有限元分析模型.通过调整节点处单元弹性模量的方法改变节点的连接刚度,并模拟节点的不同损伤工况,然后对结构的模态振型进行曲率模态计算.在Matlab软件中应用Bior3.9小波函数编程,提取曲率模态信号的小波变换系数得到损伤指标D值,根据小波变换模极大值法对桥梁节点进行损伤识别.研究结果表明,该方法能够较好地识别出损伤节点的位置,并且损伤指标会随着损伤程度的提高而增大,为钢桁梁桥的损伤检测和健康监测提供了一定的参考和借鉴.

In order to verify the applicability of the damage identification method based on curvature mode theory and wavelet transform,the finite element model of a steel truss bridge was created by using the SAP2 0 0 0 software.By adjusting the elastic modulus of the nodes,the nodes＇ connection stiffness was modified to simulate different damage conditions of the nodes,then according to the vibration mode shapes,the curvature modes of the structure were calculated.By using the Bior3.9 wavelet function programming in the Matlab software,the D value of damage index was extracted from the wavelet transform coefficients.The results show that the method can identify the location of damage nodes,and the damage index will increase with the degree of damage,which provides a reference to the damage detection and health monitoring of steel truss bridges.