Monitoring Index of Transverse Collaborative Working Performance of Assembled Beam Bridges Based on Transverse Modal Shape

Transverse collaborative working performance (TCWP) is of great importantce to assembled beam bridges' safety and serviceability, which can be charaterzied by the ability of transvese connections (hinge joints) to transfer force. This paper proposes a multi-beam model connected by distributed springs for assembled beam bridges' modal characteristic analysis. Both the strain and displacement modal shape (surface) of this multi-beam model can be expressed as a product of longitudinal base function and transverse proportional coefficient vector, which can be obtained explicitly by solving a matrix eigenvalue problem. The transverse proportional coefficient vectors in the solutions can be seen as transverse modal shapes in a cross-section. Then, two types of monitoring indexes (baseline-free and baseline-required) based on transverse modal shapes for hinge joint damage detection and TCWP monitoring are constructed. The applicability of indexes proposed is proved by numerical simulations in different damage cases and index analysis in consideration of modal noise or not.