基于虚拟变形法的桥梁索结构损伤识别研究

Damage identification of cable structures of bridge by virtual distortion method

为了实现桥梁索结构的损伤定位和定量,引入虚拟变形法(VDM),并结合遗传算法以实现准确高效的损伤识别。首先,基于虚拟变形法的基本原理,定义损伤因子;其次,推导损伤因子与虚拟变形的关系,建立以损伤因子为变量的目标函数,并采用遗传算法优化目标函数;最后,通过某实桥有限元数值算例,结合桥梁车辆静载实验过程,详细介绍了吊索损伤识别的步骤。结果证明:该方法能准确高效地实现桥梁索结构的损伤定位和定量。

In order to achieve the damage location and quantification of cable structures of bridge, the virtual distortion method (VDM) is introduced, and it is combined with the genetic algorithm to achieve damage identification accurately and effectively. Firstly, according to the basic principle of virtual distortion method, the damage factor is defined, the relationship between damage factor and virtual distortion is derived, the objective function with damage factor as variable is established, and the genetic algorithm is used to optimize the objective function. Finally, through the finite element numerical example of a real bridge, the steps of damage identification of cable structures are introduced in detail combined with the static load test process of the bridge. The result shows that the method can achieve the damage location and quantification of the bridge cable structure accurately and effectively.