Finite Element Analysis Of The Property Of Dog Bone-Castellated Beam-to-Column Joints

The rational form of Beam-Column joints in high steel structure buildings is very important to structural seismic performance. The numerous joints in the form of good seismic performance have been found successively after the Kobe earthquake in Japan and the Northridge earthquake in United States, including reduced joints and enhanced joints two categories, while the study and application of Dog-bone Joint in reduced joints type is more.During the bearing load process of Dog-bone Joint, the Dog-bone part forms a plastic hinge firstly in order to protect the joint from brittle failure, and it will help to realize the design idea of "strong joint, weak component". In recent years, it has been widely applied to the steel framework. The structural type of castellated beam has being surging forward in steel constructions, its web plate is cut by designed path according specified outspread ratio and is dislocatedly jointed, or its web plate is punched directly in order to form castellated beam with holes in beam web. Castellated beams with its beautiful shape, material savings and increased bearing capacity win steel engineers'high favor. This paper is to combine the two to form a dog bone-castellated joint and study the force performance under static and dynamic loads, which is important to the popularization and application of this kind of joint, and at the same time, provides references for establishing relevant design standards in our country and studying further.In this paper, the models are simulated by finite element analysis method, including thermal-structural coupled field simulation, bolt pretension simulation, contact simulation, static and dynamic simulation, they are involved material nonlinearity, geometric nonlinearity and status nonlinearity. Firstly, the welding residual stress of dog bone-castellated joint was researched by indirect coupling method, including temperature and stress field calculation and analysis. Secondly, on the basis of the above, the influence of welding residual stress on the static properties of joints was researched. Thirdly, in the case of ignoring welding residual stresses, the comparative study between static performance under beam end displacement loads and dynamic performance under beam end cycle repeated displacement loads was researched among dog bone joint, castellated joint, dog bone-castellated joint I and dog bone-castellated joint II.We can draw conclusions from comprehensive analyses of the finite element results that dog bone-castellated joint, comparing with dog bone joint, is no significant decrease in bearing capacity and stiffness, on the contrary, its ductility is improved in the case of reducing the amount of material, and at the same time, it retains the advantage of beautiful shape and crossing pipelines easily. In this study, the formation process of welding residual stresses and the changes of weld area, clipboard contacts and bolt pretension were emphatically researched in order to highlight the advantages of dog bone-castellated joints.