A new three-dimensional finite element analysis model of high-speed train–bridge interactions

In this study, a new finite element model for three-dimensional FE analysis of high-speed train–bridge interactions is proposed, in which various improved finite elements are used for modeling the structural constituents of a railway bridge. Specifically, the deck of a railway bridge is modeled by nonconforming flat shell (NFS) elements with 6 DOFs, which have shown high performance in the numerical examples of previous research. The track structures are idealized using beam finite elements with the offset of beam nodes and assumed to be beams on a two-parameter elastic foundation. Also, the vehicle model devised for a high-speed train is employed, which has an articulated bogie system. Using Lagrange’s equation, the equations of motion of the vehicle–bridge system can be formulated. In addition, by deriving the equations of the forces acting on the bridge considering the vehicle–bridge interaction forces, the complete system matrices of the total vehicle–bridge system can be constructed. As numerical examples of this study, a simply supported steel–concrete composite bridge and a two-span PC box-girder bridge are analyzed and results are compared with those of previous research and experimental results.