Analysis On Mechanical Behavior Of End-Plate Connections With Beam Flange Openings

Considering the issue that the traditional semi-rigid extended end-plate connections of steel frame are provided with the fracture of weld,abruption of the high-strength bolt and flexure-shear failure of end-plate,this article combine the extended end-plate connections with the thoughts of flange openings and propose a new connection named extended end-plate connections with beam flange opening.Taking advantage of FEA software ABAQUS,the mechanical behavior of the new connections of different parameters is analyzed under the static load and cyclic load in this article,and contrast with traditional extended end-plate connections.Firstly,this article investigate the effects of different beam flange openings parameters on the connection carrying capacity.Forming process of plastic-hinge,stress variation of end-plate and high-strength bolt,variation of bolt tension and stress distribution of different stress paths were analyzed.Investigation results indicate that the proper beam flange opening parameters not only shift out the plastic-hinge to openings area of beam and effectively protect the weak link of end-plate connections(weld seam,high-strength bolt and end-plate),but also only a small percentage carrying capacity was decreased.Secondly,this article investigate the effects of different beam flange opening parameters(the starting position of reduced area,the distance between openings and beam flange edge,the hole radius,the hole number),the number of high-strength bolt,thickness of end-plate and transverse stiffeners of column-web on connections of hysteretic behavior.Investigation results show that the most obvious effect on the hysteretic behavior are the hole radius,the hole number,and thickness of end-plate and transverse stiffeners of column-web.The reasonable parameters of beam flange openings makes hysteresis curve of the extended end-plate connections full and stable,and increase the energy dissipation effectively.Therefore,the seismic capacity of the new extended end-plate connections with beam flange opening is superior to traditional extended end-plate connections.The reasonable parameters of beam flange opening can overcome the disadvantage factors of extended end-plate connections,and increase the seismic capacity of connections.