Determining Orders of Modes Sensitive to Hinge Joint Damage in Assembled Hollow Slab Bridges

Hinge joint damage is the main defect that affects the safety of assembled hollow slab bridges. There are some studies on vibration-based damage detection for hinge joints. However, the effect of hinge damage on the modal parameters of bridges lacks in-depth analysis. The sensitivities of different order modes to hinge damage are dissimilar. This study determines the orders of modes sensitive to hinge damage in assembled hollow slab bridges, which is instructive for vibration-based hinge damage detection. First, the effect of the degree and location of the damage on the frequencies and curvature mode shapes is theoretically analyzed using a novel equivalent model. The orders of the modes sensitive to hinge damage are determined. Then, the numerical analysis of a bridge is performed. The equivalent model is proven to accurately reflect the dynamic characteristics by comparing it to the entity reference model. Various scenarios are established to quantitatively analyze the influence of joint damage on the partial order frequencies and mode curvatures. The accuracy of the sensitivity analysis is verified. Damage detection based on frequencies and curvature mode shapes sensitive to hinge damage is discussed briefly.