Strength and stress analysis of steel beam-column connections using finite element method

Following the Northridge and Kobe earthquakes, many studies, both experimental and analytical, have been carried out in order to get a better understanding of the seismic resistance of steel structures. Central to above issues is the seismic behavior of column-beam connection region. In order to investigate the performance of existing and improved connection configurations, four types of steel web-bolted and flange-welded (WBFW) beam-column connections with different details were analyzed by using nonlinear finite element methods. The main objective of this analysis is to determine whether the improved connection detail can contribute to the seismic resistance of column-beam joints. The ultimate strength, the stress distribution and the development process of plastic zones of connections with the raising of applied loading are calculated. The mechanical behaviors of the different detail connections are investigated and compared. This paper also briefly reviews the modeling techniques used in the nonlinear finite element analysis of steel connections for obtaining information on stress fields, the loading capacity and ultimate strength. The analytical results indicate that the seismic performance of connections can be significantly improved with alternative and modified connection details. The comparison between the results of the analysis and those of the experiment is satisfactory. The connection with modified details is proposed on the basis of analytical and experimental outcomes.