The Study on the nonlinear behavior of composite bridges is very complex. The difficulties can be attributed to the use of different materials and structural components and to their behavior under different loading conditions. A sophisticated numerical tool is therefore required to understand the structural behavior of bridges. The finite element method is a powerful tool which can be adopted to fulfill this task. In this study, a frame element and a interface element for the nonlinear analysis of composite bridges are presented. A layered model together with an incremental iterative procedure is employed to determine the response of bridges. And loading conditions under construction are presented to consider the influence of construction sequence of the deck slab ; sequential casting and continuous casting.
Various material models are developed to simulate the behavior of steel, concrete and interface media describing the interaction between girder and deck slab as well as phenomena encountered in the analysis of composite bridges. Time dependent effects due to the creep and shrinkage of concrete are investigated in the analysis of composite bridges.
Numerical examples are presented for the validation of the proposed analytical procedure.