Influence Of Stiffness Of Beam Column Joints On Seismic Performance Of Space Steel Frames

Due to its high strength,light-weight,good ductility and high toughness,in addition,the steel structure has good seismic performance,so steel structure is widely used in practical engineering,especially in large-span structures.The structure forms of steel structure mainly include: frame,steel frame,platen and net frame.One of the most widely used steel structures in steel structure is steel frame structure.Traditionally,for the analysis of steel frame joints,the beam-to-column connections are assumed to be fully rigid connections and ideally pinned.A large number of engineering practices show that the joints fall between the two extreme cases of fully rigid and ideally pinned,which are called semi-rigid joints.In this paper,the effect of node stiffness on the seismic performance of the space steel frame was studied.In order to simplify the calculation,the space steel frame is often neglected secondary factors,making the structures as possible as possible planarization.Although it reduced the computation,it ignores the role of space steel frame,which will lead to great error,or even incorrect results.In this paper,the spatial properties of the steel frame and the elastoplastic analysis of a space steel frame with semi-rigid connections are briefly introduced.In this paper,ABAQUS is used to establish the spatial steel frame model.The SPRING2 element is used to simulate the beam-to-column connections,and the stiffness coefficient of the node is introduced.The different moment-rotation curves are used as the node constraint condition to control the connection stiffness of the beam-to-column connections.The model is verified by comparing the simulated curve with the experimental curve of the load displacement of a single span two-layer welded joint space steel frame.The above results show that using the SPRING2 element to simulate the stiffness of the beam-to-column connections and using ABAQUS to analyse the seismic performance of space steel frame are feasible.By setting a series of different influence of the joint stiffness coefficient values,a six-floor-two-span space steel frame is modeled with different beam-to-column connections stiffness,wnich were carried on the uniaxial loading,cyclic loading and earthquake loading.The effect under different ?factors on the seismic performance is discussed,such as steel frame bearing capacity,ductility,energy dissipation and Seismic performance of different connection stiffness conditions of space steel frame.The results show that the semi-rigid connection has significant influence on the seismic performance of space steel frame structure.When the ? is between 1/17 and 1/20,the bearing capacity of the space steel frame is high,and the ductility is relatively good.Compared with the rigid connection,when the node is semi-rigid connection,the natural vibration period of the lower order form decreases,and the dynamic response of the structure changes little,but the deformation is larger.The research results obtained in this paper have some reference value for further research on semi-rigid connection space steel frame's performance.And the conclusion can serve as guidance for actual engineering.