Damage identification with generalized flexibility perturbation method under ambient excitation

A generalized flexibility perturbation approach for structural damage detection was presented here under ambient excitation. By appropriately converting the generalized flexibility perturbation equation,the mass normalization coefficients a structure's first several modal of shapes and the elemental damage parameters were calculated simultaneously using the least-square method. With the proposed approach,not only the damage level of the structure was recognized, but estimates of the mass normalization coefficients also were obtained. The effectiveness of the proposed method was illustrated using the simulated data and the measured noise for an example of a two-storey frame structure. The results showed that the proposed method can be used to identify structural damages accurately only using a structure's first several modal shapes; the predicted mass normalization coefficients of the measured modal shapes with the proposed method have a good accuracy; the proposed procedure is computationally attractive and simple to implement,it is useful for structural damage identification under ambient excitation.