AN INVESTIGATION ON THE BEHAVIOUR OF THE MODIFIED BEAMTO- COLUMN CONNECTIONS BY MEANS OF NON-LINEAR FINITE ELEMENT METHOD

摘要

The behaviour of beam-to-column connections has an enormous effect on strength andrnductility of steel frame stuctures. The weakness of these connections against earthquake froces during thernNorthridge earthquake necissitated a serious concern about the development of new design methods. Thernnew design method, which is based on the cut-off of the beam flanges near the connection, has been ablernto upgrade its ductility and its capacity for energy dissipation. This paper presents the analyticalrnresponses of four beam-to-column connections with the trimming beam flanges tested by Chen et al.rn(1996). The results reveal the capacity of the nonlinear finite element method as a powerful supplement tornthe experimental investigations where necessary. The nonlinear finite element analysis of the connectionsrnwith cut-off flanges is used to determine their plastic rotational capacity. The results show that the plasticrnrotational capacity of this type of connections are increased several times compared to ordinary beam-tocolumnrnconnections while their stiffnesses are decreased slightly.