Finite Element Modeling And Analyzing For Four-angle Connection Joints Of Beam-to-Column In Steel Frame

To simplify the analysis and design process,the beam-to-column connections are often assumed completely rigid connection,or ideal hinge joint in the traditional steel frame design. Although these assumptions make analysis and design process greatly simplified,but a large number of engineering practices and theoretical experiments indicated that the beam-to-column connection is semi-rigid.In semi-rigid connection field,scholars abroad have already done some research ahead of Chinese scholars.A little research have be done in china up to today,so there is no specialized steel connecting code,only in the"code for design of steel structures"for the beam-to-column connection give the general provisions.In this paper,ANSYS is used to analyze the four-angle connections.The nonlinear influence of geometric,material and state is taken into account while it is used to the triaxial nonlinear finite element analysis of the model that 8-node solid element SOLID45,contact element CONTA174 and TARGE 170 are used.Finite element analysis have taken into account the thickness of column flange,column web thickness,top and seat angles thickness,web angles thickness,beam height and diameter of bolts.The cyclic loading analysis is implemented. Curves about moment-angle,stiffness of degeneracy are obtained in this paper.It is indicated that:Four-angle connections are a typical semi-rigid connections with the full hysteresis loop and a preferable ductility and dissipative capacity;increasing the top-bottom angle thickness,column flange thickness and beam height can significantly increase the ultimate bearing capacity and the initial stiffness of the connections;increasing web angle thickness or bolt diameter also have some influence on the ultimate bearing capacity of the connections; thickness changing of column webs has little to do with the ultimate bearing capacity of connection;connection's geometric parameter variations and loading mode changing only have some influence in its bearing capacity and initial stiffness,and none in its nonlinear.In this paper,the mechanical behavior of four-angle connections are carried out an in-depth analytical study,and it will obviously speed the further research and promotional use of the connections for reference model and theoretical analysis basis provided in this issue.