A Study On Design Method Of Plastic Hinge Appear In The Splicing Location Of Beam In Column-Tree Frame

Beam-to-column connection with cantilever beam bolted-splicing in rigid steel frame is called column-tree frame in abroad. This beam-to-column connection is widely used in multi-stories or high-rise building in the U.S.A and Japan, which is also the recommended connection type in our Technical Specification for Steel Structure of Tall Building and Code for Seismic Design of Building. In this kind of connection the cantilever beam is welded in workshop and beam is spliced on-site using high-strength bolts, which have a better energy dissipation and plastic rotation capacity. Usually the seismic design method of beam-to-beam splicing connection joint in beam-to-column connection with cantilever beam bolted-splicing is equal-strength method. Little research has ever been done on this kind of connection. The aseismic superiority of this connection has not brought into play. So the research of this kind of connection is not only significant to the theoretical aspect, but also important in practice.This paper presents the viewpoint of make the plastic hinge appear in beam-to-beam splicing joint in beam-to-column connection with cantilever beam bolted-splicing, and the design method of plastic hinge appear in beam-to-beam splicing joint in beam-to-column connection with cantilever beam bolted-splicing is given out. Through computer modeling using finite element program with material, geometry and state triple-nonlinear taken into account it is confirmed that the beam-to-column connection with cantilever beam high-strength bolted-splicing can appear plastic hinge in beam-to-beam splicing joint, which is designed using the design method in this paper. Plastic hinge appear in beam-to-beam splicing joint can effective protect beam-to-column welded joint and reduce the possibility of fragility damage of beam-to-column welded seam. This paper compare the performance under forces of beam-to-column connection with cantilever beam bolted-splicing which is designed using design method in this paper, beam-to-column connection with cantilever beam bolted-splicing which is designed using equal-strength method and non-beam splice connection. From compare some important conclusions is give out.