Stability And Danamic Analysis Of Space Steel Frames With Semi-Rigid Connections

Multi-storied or high-rise steel framed structures are in the ascendant as an important structural system. The effects of the different connection stiffness on the global stability of structures are mainly researched in this paper, which is not given enough attention in existing researches. Development of steel frame structures, current research of global stability of steel frame structures, existing problems and structural stability theory are introduced. The finite element method for stability analysis of structures is introduced emphatically.On base of concept effective length factor of columns in semi-rigid steel frames stability design, by considering semi-rigid moment-rotation nonlinear behavior of semi-rigid connection in whole loaded range, finite element models of steel frames with semi-rigid and rigid connections were established using ANSYS program. Nonlinear finite element analysis of steel frames with four angle connections and top-seat angles connections and double web angle connections were conducted in literature. Through buckling analysis of sway space steel frames with semi-rigid connections, the effective length factor of sway space steel frames was derived, which considered nonlinear rotation of top-seat angles and double web angel joints. In conclusion, a simple formula of effective length of semi-rigid column was brought forward for engineering design.By the method of finite element, 8 space frame models were built up including double web angle connections, top seat angle connections,four angle connections and rigid connections, whose floor is 3-storey, 12-storey. The former three vibration modes were gained with model analysis, and period varieties of different connections were compared; time-history analysis were done by inputting ground motorial acceleration including El centro wave,Qianan wave and Lanzhou wave. The effects of several factors including connection relative stiffness and different earthquake waves were studied on storey displacement and relative rotation angles.The results in this paper provide reference for further study on behavior of semi-rigid connection space frames and design of semi-rigid connection space frames...