Structural Damage Identification in Plates Using Measured Dynamic Responses

In this paper, a response sensitivity-based approach is presented for identifying the local damages in isotropic plate structures directly from the measured structural dynamic responses. The local damage is simulated by a reduction in the elemental Young's modulus of the plate. In the forward analysis, the finite element forced vibration response of the plate under external force is obtained from Newmark direct integration method. In the inverse analysis, a dynamic response sensitivity-based finite element model updating approach is used to identify local damages of the plate in the element level. The solution is obtained iteratively with the penalty function method with Tikhonov regularization using the measured structural dynamic responses. A numerical example is conducted to illustrate the correctness and efficiency of the proposed method. Both single damage and multiple damages cases are studied. The effects of measurement noise and measurement point on the identification results are investigated. Studies in this paper indicate that the proposed method is efficient and robust for both single and multiple damages for plate structure. Good identified results can be obtained from the short time histories of a few number of measurement points.