Damage identification method of girder bridges based on finite element model updating and modal strain energy

A timely and accurate damage identification for bridge structures is essential to prevent sudden failures/collapses and other catastrophic accidents. Based on response surface model (RSM) updating and element modal strain energy (EMSE) damage index, this paper proposes a novel damage identification method for girder bridge structures. The effectiveness of the proposed damage identification method is investigated using experiments on four simply supported steel beams. With Xiabaishi Bridge, a prestressed continuous rigid frame bridge with large span, as the engineering background, the proposed damage identification method is validated by using numerical simulation to generate different bearing damage scenarios. Finally, the efficiency of the method is justified by considering its application to identifying cracking damage for a real continuous beam bridge called Xinyihe Bridge. It is concluded that the EMSE damage index is sensitive to the cracking damage and the bearing damage. The locations and levels of multiple cracking damages and bearing damages can be also identified. The results illuminate a great potential of the proposed method in identifying damages of real bridge structures.