ABSTRACT
In order to investigate the fatigue crack propagation behavior of welded gusset plates for diagonal braces of steel-concrete composite girder bridges, digital fatigue tests are carried out, taking one steel-concrete composite bridge as the case. The sequential coupling method is used to simulate the whole welding process of the welds of the diagonal braces gusset plates, and fracture mechanics theory and extended finite element method are applied to simulate the fatigue crack propagation. Results show that the effect of welding residual stresses cannot be ignored. Typical fatigue cracks at the welded gusset plates of diagonal braces are Mode I-II-III composite cracks dominated by Mode I. The effects of Mode II and III cracks are non-negligible in fatigue assessment of welded gusset plates for diagonal braces.
