Finite Element Analysis Of Beam-to-Column End-Plate Connections In Steel Structure

Beam-to-column connection is an important and complicated content in the steel frame design. The reliability of connections has much important influence on the behavior of whole steel fame. Traditionally, it was regarded that steel frames with welded beam-to-column connections had excellent performance, so it were widely adopted in steel constructions. During the Northridge earthquake in 1994 and Kobe earthquake in 1995, a large number of steel Moment-Resisting Fames experienced brittle fractures at beam-to-column connections. The new-type connections and semi-rigid connection have been becoming the hot research subjects gradually in recent years. This paper draws lessons from the research approaches of some scholars on the basis of existing research results. Semi-rigid end-plate connections of beam-to-column are systematically analyzed and researched by using the theoretical analysis and nonlinear FEM.Firstly, according to the anti-seismic design principle of strong column and weak beam of steel frame and ideal of controlling the position of plastic hinge of beam effectively, the connection form that is impaired by hole on web is proposed. The influence of different impaired radius and impaired distance on initial stiffness, ultimate elastic bearing capacity, the location of plastic hinge is analyzed in this paper.Secondly, the stress distribution of end-plate is discussed in detail. The laws of the stress distribution on beam flange and web are revealed and the microscopic reason that the plastic hinge occurs near the section reduced most is explained rationally.Thirdly, the stiffness, ultimate elastic bearing capacity and the hysteretic behavior of more than 30 end-plate connections are analyzed under cyclic load and the influence of the change of construction in details on performance of the connections are also discussed in this paper. It shows that adopting the connection structural form with a hole in web can change the stress distribution of beam flange, the hysteretic behavior of connection and the failure mode. It improves the anti-seismic performance of the connections further. Some good suggestions that are important to design and construction of semi-rigid connections of beam-to-column in steel fame can be obtained.