基于索力变化的斜拉桥主梁损伤识别方法

In recognizing the redistribution of dead-load internal forces of stay cables due to structural damage, a new method that utilizes the changes in the cable forces to detect the damage in bridge girder is proposed. The damage location and its extent are determined based on sensitivity-based finite element model updating. The regularization technique is enforced in solution process to mitigate the ill-conditioning. The validity of the method and its robustness to measurement noise is illustrated by numerical simulation study of damage detection of cable-stayed Sutong Bridge with a main span of 1 088 m. It is shown that the proposed method correctly identify the damage location and its extent for the case of noise-free simulation data. In the case of low level of measurement noise and of damaged elements being well spaced, the accuracy of the method is acceptable. The accuracy of identification is greatly improved when the cable linking with the damaged elements are available for identification.