基于归一化主模态差的装配式钢桥导梁损伤识别

Damage Identification of Assemble Steel Bridge Guide Rail Based on Normalized Main Modal Displacement Difference

为了解决装配式钢桥在结构损伤下的识别问题,选取了归一化主模态差作为标示量,对装配式钢桥导梁结构进行损伤识别。通过实测模型与有限元分析模型的固有频率和对应振型比较,验证桥梁导梁有限元模型的正确性;提出了运用归一化主模态差曲线图识别桥梁导梁损伤的方法,利用结构损伤时归一化主模态比无损伤时的归一化主模态刚度下降,损伤节点处振幅相对于正常状态数值增大,产生归一化主模态差正向突变来反映结构局部损伤的位置和损伤程度。通过模拟六种工况得到结构损伤部位会引起主模态差曲线的正向突变;并且损伤程度越重,对应的归一化主模态差越大。验证了损伤状态和正常状态之间的主模态差曲线可以判别装配式钢桥导梁的损伤位置和损伤严重程度。

In order to solve the problem in the identification of assemble steel bridge structural damage,normalized main modal displacement difference is selected as labeled amount to identify damage of assemble steel bridge guide rail. Compare the finite element modal analysis of guide rail with the actual measurement to prove the validity of the finite element model. Graph of normalized main modal displacement difference can be used to identify structural local damage location and damage degree due to stiffness decrease of structural damage. Forward mutation of normalized main modal displacement difference can be observed by simulating six kinds of guide rail damage conditions,which can vertify correctness of normalized main modal displacement difference in damage identification.