Damage Identification of Multi-box Steel-concrete Composite Bridges Based on Modal Curvature Difference Method

摘要

Based on the data from dynamic analysis of a 40m-span multi-box steel-concrete composite bridge and the difference value of its modal curvature before and after the structural damage, this paper detects the damage locations in steel-concrete composite bridge by modal curvature difference method (MCDM).Here we adopt the updated finite element model in last work as analytical model, taking concrete density and elastic modulus as updating parameters and modal frequency+MAC as reference data.The results indicate that the modal curvature difference method can well locate the damages in steel-concrete composite bridge, especially the damage in concrete.But the change rate of frequency as damage index is insensitive to the bridge damage and the method can't be applied solely for practical.