Anti-seismic Performance Study Of New Type Of Beam-column Connection In Multi-Story Steel Frame

Connection is divides into rigid connection, semi-rigid connection, ideal pin connection, and is an important and complicated content in the steel frame design. The reliability and effectivity of connections has much direct influence on the behavior of whole steel frame. Especially after the unexpected numerous brittle connection failures happened in the 1994 Northridge earthquake, many scholars have been attaching great importance to the observed connection problems in project circle, witch is one of the hot research subjects in recent years. This paper draws lessons from the research approaches of some scholars on the basis of existing research results. T-type connections of beam-to-column are systematical analyzed and researched by using the study methods of experiment study, theoretic analysis, nonlinear FEM.Firstly, According to the antiseismic design principle of strong column and weak beam of steel frame and the idea of controlling the position of plastic hinge of beam effectively, the connection form that is impaired by hole on web is proposed, and five groups of test specimens with the different position and size of the hole are fabricated. At the same time, the failing test of five groups specimens under cyclic loading are carried out. The stress distribution of key position in the connection region, the hysteretic behavior of connection, and the failure mode and ultimate bearing capacity of connection are'discussed. Moreover, the influence of different structure on connection behaviors is also analyzed in this paper.Secondly, the semi-rigid connection such as angle connections combined with advantages of rigid and hinge is also researched exploringly in this paper. At the same time, the structural form with the hole in beam web is introduced to the semi-rigid angle connection, and four groups tests under cyclic loading are carried out. The decrease of initial stiffness, the hysteretic behavior of connection, the constraint relation and the ultimate bearing capacity of connection are discussed. The relative conclusions are obtained and provide some advise for the design and construction of the beam-column semi-rigid connection of a steel frame.Thirdly, by using the nonlinear finite element program named ANSYS program, three types of connections with different structure form are analyzed, and contrastive analyses are carried out with testing results. The comparison between the results of analysis and those of test is satisfactory. Theoretical calculation and testing results show that adopting the connection structural form with a hole in the web can change stress distribution of beam flange, the hysteretic behavior of connection, the failure mode and transform the failure mode of the connection from fragility damage to local buckling damage of beam, then reduce the possibility of fragility damage of weld, which improve the ductility performance of connection to a certain extent.Finally, some conclusions and suggestions that are important to design and construction are obtained, and which provides a good basis for the further research of the connection behavior of beam-column connection.