Finite element analysis of ultimate load-carrying capacity for double-deck and three main trusses steel bridge with rigid cable

The finite element software ANSYS was used to create the finite element model of the Dongjiang bridge, a new kind of bridge with double-deck and three main trusses steel bridge with rigid cable, and its ultimate load-carrying capacity was obtained by nonlinear buckling analysis. Based on the simplified methods and theoretical assumptions used in finite element calculation, the overload capacities of bridge for live load and the failure sequence of main truss members were gained. At the same time, the structural failure mechanism in the ultimate limit state was basically obtained. The results show that the overall deformation is small when the structure fails and the failure of the bridge mainly results from the main truss members reaching to the material strength; the rigid stiffening chords affects the overall mechanical performance of the bridge greatly and increases the structural load-carrying capacity effectively.