Nonlinear Finite Element Analysis Of Semi-Rigid Connected Steel Frame

There are many forms of tall steel structures; however frame structure is the most basal one. In conventional analysis and design of steel structures, it is usually assumed that the connections between columns and beams are either rigid or pinned. The analysis of steel frames adopting the assumption can simplify the procedure of analysis and design, but cannot precisely reflect structural practical circumstance and the errors of calculating results are large, even, get incorrect conclusions. In fact, the behaviors of beam-to-column connections are between to fully rigid connection and ideal pin connection, and belong to semi-rigid connection. If the beam-to-column connections are assumed fully rigid connection, the constraint action of joint is magnified and the structure lean to unsafe. If the beam-to-column connections are assumed ideal pin connection, the constraint action of joint is neglected. Therefore, the influences of semi-rigid connection on steel frame structure are fully taken into account in the analysis and design of steel frame.In recent years, quite a lot of earthquakes in the world indicate that steel frames with welding joint easily occurs brittle collapse because of having a low ductility at joints. Then, a semi-rigid connected steel frame has large the energy absorption capacity which can resist dynamic loads. The purpose of this paper gives some theoretic reference for seismic design of steel frame structure through the research on the seismic capability of steel frame with typical semi-rigid connections.The present findings of semi-rigid connections, the method for design of beam-to-column connections in the codes from China and other countries, and the character about semi-rigid connections, were briefly introduced in this paper. The M-θ_r relation curve and the computing equations about the initial stiffness and moment capacities of top-seat angle and double web-angle semi-rigid connection were discussed. In this paper, Pseudo-static force testing of steel frame with semi-rigid connections is carried out in order to obtain elastic-plastic behavior of semi-rigid connections steel frames under cyclic loading Through the analysis of test data, the collapse characteristic after structural ultimate strength has lost and the coming order of plastic hinges are studied. The hysteresis properties, ductility and dissipative character of this kind of semi-rigid connection are discussed. And in this paper, nonlinear finite element simulative computing analysis about the semi-rigid connection and steel frame with semi-rigid connection are carried out with ANSYS finite element software. A few beneficial conclusions are attained due to the comparison with test results. At last, base on the work of this paper, some problems about this research worth to be studied afterward are put forward.