The Performance Research On Square Tube Column-beam Node Of Prefabricated Steel Structure

It is well known that fabricated structure has short construction period,high material utilization,low engineering pollution and a series of advantages,for a frame structure,the performance of the node is particularly important.Square steel tube column with small surface area and strong axis and weak axis of bending stiffness were similar.At present,our country mainly aimed at the square steel tube column-H beam and square steel tube column-I iron beam node performance research,studies of square steel tube column-truss beam node are few,the square steel tube column-truss beam node has been promoted.Therefore,the research and development of square steel tube column-truss beam node to node has high practical value in the promotion of new construction.This article established four kinds of models in the form of the node by finite element software:side column without brace;side column with brace;mid-column without brace;mid-column with brace.The nodes in the nonlinear analysis under monotonic loading,and analysis of the effects of the setting of the brace.Study the ultimate bearing capacity of the node,the initial stiffness,failure pattern,the Angle and the beam Angle change with the axial load.Nonlinear simulation analysis shows that the node strength,stiffness and rotation capacity increases and then decreases gradually with the increase of axial force,the existence of the brace is not only effective transfer of the plastic hinge,but also improve the strength,stiffness and rotation capacity of the node.Compiled three kinds of methods for the determination of node type theory,this paper uses the nonlinear M-?_r relation curves of four types of nodes to determinethe stiffness category.The results show that the rigid node changes with the axial force.In addition,the inflection point method calculation and analysis of existing buildings,analysis the building meet the requirements,there is enough safety reserve.Finally,put forward about the square steel tube column-truss beam node need deeper research question.