Multiscale fatigue crack growth and life prediction for complex details of steel bridges
Since the traditional macroscopic phenomenology cannot describe the multiscale evolution process of fatigue damage in steel bridges from micro to macro,a method for describing the multiscale fatigue crack growth and life prediction in complex structures of steel bridges is proposed.Firstly,combining with the mi-croscopic crystal plasticity constitutive model,a microscopic short crack nucleation and growth model is estab-lished based on the energy dissipation theory.Meanwhile,a model for macro long crack growth is established by combining the linear elastic fracture mechanics.On this basis,taking the welding structure details of typical longitudinal rib and roof plate of steel bridge as the research object,the whole process of nucleation and propa-gation of micro short crack and macro long crack is simulated and verified using the existing fatigue test.The numerical simulation results are basically in agreement with those of the test.It is shown that the proposed method for predicting multiscale fatigue crack spanning and life has good applicability for fatigue damage evo-lution and assessment of details of steel bridges with complex structures.
万方数据
维普
