Reliability-Based Damage Identification Using Dynamic Signatures

Abstract

Because of the influence of the stochastic nature of structural properties and field measurements, the identification result of damage extent is, in essence, uncertain, causing possible deviations and affecting the reliability of the identification result. To give a probabilistic measure on the identification result of damage extent, a reliability-based damage identification method based on dynamic signatures is proposed in this study. The Monte Carlo simulation in conjunction with the response surface method is used to perform the reliability analysis of damage identification with given accuracy, and a trial-and-error procedure is proposed for conducting damage identification with acceptable reliability. The influence of both structural uncertainties and measurement noises on damage identification can be taken into account in the present approach. Meanwhile, the proposed method is capable of assessing the robustness of different types of dynamic signatures against noise and the sensitivity of various random parameters involved in structural damage identification. The present approach is applied to the probabilistic damage identification of a simply supported beam and a long-span arch bridge, indicating the feasibility and effectiveness of the proposed method for both simple structural components and complex structural systems.