The Effect Of Welding Residual Stress To The Performance Of Resistance To Earthquake Of Beam-column Connection

The facts that Brittle fracture occurred in the weld of beam-column welded connection in steel structure in the earthquake of Northrige in America in 1994 and Kobe in Japan in 1995 showed that welding residual stress is the important factor which lead to this kind of brittle fracture. Therefore it is very important to study the effect of residual stress to the performance of resistance to earthquake of beam-column connection to ensure the safety of resistance to earthquake of the steel structure. This paper is mainly concentrated on the study the effect of residual stress to the performance of resistance to earthquake of beam-column connection, and covers the following aspects concerning the main work and research in the project. 1) A beam -column welded connection finite-element(FEM) of welding temperate field and stress-stain is founded and the material non-liner(it means that that the thermo-physical properties and the mechanical properties of the material are depending on the temperature and changing ) is considered .The temperature field of real welding process and the changes of stress-strain fields in steel structure and the residual stress distributions are accurately simulated. 2) The different details of beam-column connections are analysed by ANSYS in both elasticity and elaso-plasticity condition, the boundary conditions of which are provided by the Push-over calculation outcome which superposed welding residual stress of beam-column. The results of study showed that to the different variety of beam-column welded connection whether it be in a elasticity or elaso-plasticity condition, the residual stress make the stress of flange welded in high level, and weaken the function which protect the flange welded by moving plastic hinge outwards.