Inelastic load capacity analyzing of steel I-girder bridges with shakedown method

This paper presents a shakedown FEM method to analyze inelastic load capacity of steel I-girder bridges. The shakedown limit state is important for the safety of steel bridges that must resist heavy repeated traffic weights. In order to analyze the old steel I-girder bridges, shakedown theory was used and a finite element program was constructed. Using loading increment method and layered beam element, the program could simulate the whole shakedown process of a structure and get the shakedown limit load easily. Compared with corresponding references, the analytical results showed that the program could simplify the calculation of the shakedown limit load, and its precision was under 1%.