Analysis On The Mechanical Performance Of Castellated Lightweight Steel Portal Frame Node

With the development of science and technology as well as people's demands for material and cultural life,the modern society has put forward new and higher requirements for all kinds of buildings,so it brings the innovation of architectural structure system and components.This paper focuses on the mechanical properties of honeycomb light steel portal frame.It summarizes the previous research on honeycomb beam and honeycomb column and honeycomb beam column,and uses ABAQUS6.11 finite element analysis software,according to the relevant specification and the experience of the scholars in the literature,designed the paper to simulate the specimen.It considers the effects of three factors on the mechanical properties of the honeycomb light portal frame,including the shape of the opening,the form of the end plate and the stiffeners at the end plate.The process of static loading FEM simulation,this paper mainly analyzes the influence of the above three factors on the stress variation of honeycomb girder flange and the stress of honeycomb column flange.The influence of the three factors on the static performance of the honeycomb beam was analyzed mainly from the stress variation of the honeycomb beam flange and the stress of the honeycomb column flange.The low-cycle reciprocal cyclic loading of the simulated specimens is carried out and the influences of these three factors on the failure modes,hysteretic curves,skeleton curves,nodal bearing capacity,stiffness degradation,ductility and energy dissipation are discussed.The following conclusions can be drawn from the analysis:(1)The influence of hole shape on the mechanical properties of joints: The stress of the solid-web nodes of the beam nodes in the beam end node domain and the column end node domain is larger than that of the honeycomb nodes.The location of the abrupt change of the stress of the column of the solid-web nodes at 500 mm above the column bottom,which is equivalent to the position near the column height 1/3;The destruction of the real node is mainly in the vicinity of the node domain but the destruction of the cellular nodes are mainly concentrated in the honeycomb openings.Under the same loading condition,the failure rate of the honeycomb nodes are larger than that of the solid-web nodes;The ultimate load,ultimate bearing capacity and equivalent rigidity of the honeycomb joint are larger than that of the solid web node;But the ductility and energy dissipation performance of the solid-web nodes are larger than those of the honeycomb nodes.For the honeycomb nodes of the ultimate load,ultimate load capacity,equivalent stiffness,the ductility and energy dissipation performances of circular hole cellular nodes are better than regular hexagonal hole node;The regular hexagonal hole is better than the square hole?(2)The influence of end plate placement on the mechanical properties of joints: In the case of the solid-web nodes,the stress of the top flange of the end plate stand are larger than that of the end plate flat in the vicinity of the beam nodes;For the honeycomb beam and column nodes,end plate flat nodes are greater than the end-plate stand nodes in cellular beam column flange node domain stress;Under the low-cycle reciprocating cyclic load,when the ultimate load of the honeycomb joint reaches the same deformation at the beam end,the end plate stand nodes are larger than the end plate flat nodes;But the solid-web nodes are opposite,the ultimate load of end plate nodes are larger than those of the end plate stand nodes in the same deformation on the beam end;The ultimate bearing capacity equivalent stiffness,ductility and energy dissipation performance of the end plate flat nodes are larger than those of the end plate stand nodes,regardless of the honeycomb nodes or solid-web nodes;when the end plate is vertical,the end bolt is easily damaged.(3)The influence of the stiffeners on the mechanical properties of the joint: For the solid-web nodes,the stress of the beam flange of the end plate with the stiffeners is greater than that of the end plate without the stiffeners;The stress in the vicinity of the joint node of the end plate with no stiffeners is greater than that of the stiffeners on the end plate;For honeycomb nodes,the stress on the beam flange and the column flange of the end plate without stiffeners is greater than that of the stiffeners on the end plate;For the solid web nodes,the ultimate load of the stiffener is greater than that of the end plate without stiffeners and the honeycomb nodes are just the opposite;The ultimate bearing capacity,stiffness,ductility and energy dissipation of the joint with stiffeners are greater than those with no stiffeners at the end plate.