Space shape finding FE analysis for suspension bridge based on CR formulation method

The problem of geometric non linearity simulation for spacial cable system was solved by introducing the truss element based on corotational coordinate (CR) system, cable structure materials and node coordinates and automatic refreshing algorithms for element internal force. And the shape finding problem for maneuvering profile was solved with the Newton Raphson based on energy convergence criteria with search function. This has avoided the regular truss element assumption extensively used in traditional methods and catenary elements which have difficulties in practical application because of the complicated formulas. The use of CR formulation has taken into account the stiffness outside the cable plane via a geometric stiffness matrix, realizing the 3D space analysis of a cable bridge and improving the efficiency and precision for the space geometric non linearity analysis and cable structure, and enabling more precised simulation of geometric form finding and internal force of the large span suspension bridge main cable under construction.