ABSTRACT
ABSTRACT: This work tested and studied the degradation of ultimate bearing capacity under cyclic fatigue load at the junctions of a steel-concrete composite beam bridge. A fatigue life model of stud connectors was established based on fracture mechanics, taking the initial defects of components into consideration. A method to identify the relationship between residual shear bearing capacity and times of cyclic loading with constant amplitude was proposed based on parameter fitting from experimental data. Parameter analysis for various diameter, initial defect and amplitude of shear stress was conducted by using this method. The results showed that the degradation degree of the shear bearing capacity for the stud with a larger diameter is greater than that of the stud with a smaller diameter. When the initial defect rate of the stud is greater than 0.1 and the amplitude of shear stress is greater than 100 MPa, shear bearing declines rapidly and needs to be controlled during engineering design.
