Numerical calculation on the seismic performance of a steel frame beam-to-column joint with welding residual stress

Abstract

ABSTRACT Residual stress has almost always been an essential issue associated with welded structural steel. In this paper, thermal elastic–plastic finite element method (FEM) is adopted to calculate the welding residual stress of a steel frame beam-to-column, and then the calculated residual stress is applied to the subject as an initial condition to calculate its mechanical behaviour. Both monotonic loading and cyclic loading are designed to simulate the seismic behaviour of the structure. Bonora damage model [41–44] is used to calculate the initiation and propagation of the crack. Finally, the hysteretic curve of the structure under cyclic loading is obtained. The results show that the main component of the welding residual stress along weld fillers of the steel frame beam-to-column is longitudinal tensile stress, and the magnitude of the residual tensile stress in welding stable zone is about 1.2 times of the material yield stress. Welding residual stress mainly affects the ductility and fracture behaviour of the steel frame beam-to-column. Under monotonic loading, the drift ratio of crack initiation with welding residual stress is reduced by 9% compared with that without welding residual stress. Under cyclic loading, when welding residual stress is taken into account, the crack initiates a little earlier than when welding residual stress is not considered. Compared with monotonic loading, crack initiates much easier when the structure is subjected to cyclic loading.