The Suspension Bridge Structure Optimization Based On ANSYS

This paper is based on the existing suspension bridge research results. Firstly, it expounds the basic theory of suspension bridge, the theory of optimization design and the basic knowledge of parametric modeling. At the same time it uses the APDL parametric design language of ANSYS for suspension bridge finite element modeling, aiming at the optimal design of suspension bridge.Combined the structural style with the character of external force of the suspension bridge, we use3-D bar elements to simulate the suspender and the cable of suspension bridge, we use the beam elements to simulate the stiffening girder and bridge tower, with the shell element to simulate bridge panel.So that we can build the finite element model of the all bridge pace analysis,which is made up with the cable, suspender, pylon, girder, bridge panel.We use the strong nonlinear finite element analysis and optimization design function of the large general software ANSYS, and the ANSYS APDL parametric design language, and the optimization method of continuous design variables to optimize the suspension bridge with reasonable optimization strategy. We use the suspender and cable initial strain as design variables; Regard the possible tension of suspender and stress limit of the cable, suspender, stiffening girder, the tower’s as the state variables; The objective function is the minimum of main girder deformation when the suspension bridge is under dead load.Firstly,we use stochastic search optimization method, and base on all the feasible design sequence basis of it, we use zero order method and then the first order method to get a more accurate results.Through the above analysis, we can carry on optimization analysis before and after comparing state, including the static analysis, modal analysis, and transient analysis. Through the optimization of suspension bridge before and after comparing state, we can make the suspension bridge a better state.