A frequency response function-based structural damage identification method

This paper introduces an frequency response function (FRF)-based structural damage identification method (SDIM) for beam structures. The damages within a beam structure are characterized by introducing a damage distribution function. It is shown that damages may induce the coupling between vibration modes. The effects of the damage-induced coupling of vibration modes and the higher vibration modes omitted in the analysis on the accuracy of the predicted vibration characteristics of damaged beams are numerically investigated. In the present SDIM, two feasible strategies are introduced to setup a well-posed damage identification problem. The first strategy is to obtain as many equations as possible from measured FRFs by varying excitation frequency as well as response measurement point. The second strategy is to reduce the domain of problem, which can be realized by the use of reduced-domain method introduced in this study. The feasibility of the present SDIM is verified through some numerically simulated damage identification tests.