Structural damage identification using static test data and changes in frequencies

摘要

In this paper, a two-stage identification algorithm for structural damages is presented using measured static displacements and changes in natural frequencies. In the first stage, a damage signature matching (DSM) technique is improved to detect the damage locations. In the damage signatures, the data of static deformation and natural frequencies are employed jointly and the effect of damage severity is eliminated effectively. The damage locations, then, can be detected successfully by matching measured damage signature (MDS) with predicted damage signature (PDS). After obtaining the possible damage locations, an iterative estimation scheme for nonlinear programming, based on the quadratic programming technique, is proposed to predict damage extents. Two examples are given to illustrate the effectiveness of the present algorithm. The first one is a planar truss and the test data are simulated numerically. The second one is a beam with two clamped ends, in which the data are obtained experimentally. The results show that the proposed algorithm is efficient for the damage identification of certain structures.