Concurrent multi

Fatigue damage is one of the leading causes for structural failure of long-span steel bridges, but fatigue damage evolution of a long-span steel bridge is very complex. This study proposes a concurrent multi-scale fatigue damage evolution simulation method for long-span steel bridges from micro short crack nucleation and growth to macro structural component damage until mega structural failure. As a case study, the fatigue damage evolution of the Stonecutters Bridge in Hong Kong under cyclic vehicle loading is finally simulated using the proposed method. It shows that the proposed method is computationally feasible even for such a large scale structure. The method can provide a clear picture how micro short cracks grow into macro fatigue damage of structural components and eventually lead to mega structural failure