Finite Element Analysis On Joint With External Stiffening Ring Of Square Steel Tubular Column To H Shaped Steel Beam

In recent years,china’s steel output grows gradually,but in our country,steel structure proportion is lower than that of developed countries.The steel structure industry in our country still has a large development space.Steel structure building has superior construction convenience and good seismic performance,in addition,it has characteristics of green environmental protection and energy saving.The above advantages all conform to the construction concept of resource-conserving society of China.Cold-formed square steel tube has reasonable mechanical properties,and then connection with stiffening ring and flange-plate connection both have good seismic performance.However,major research,nowadays,are focus on square steel tube column joints and research on rectangular steel tube column joints are relatively few.Based on the completed text on H-shaped beams to square steel tubular columns with the outer reinforced diaphragms joint,the effect of steel consumption of steel tube columns,ratio of length to width of column section under the condition of equal columns steel consumption and strength ratio of column to beam on the mechanical properties were explored.In the mean time,the effect of external length of reinforcement rings,external width of reinforcement rings,angle width of flange of reinforcement rings,thickness of plate of reinforcement rings on the failure mode,bearing capacity,ductility,energy dissipation capacity and strain distribution were explored.The main results are as follows:(1)Under the condition of axial load or bias load,with the increasing of the ratio of length to width of column section,specimens ductility coefficient decreases obviously.With the increase of eccentricity,ultimate bearing capacity show clear decreasing trend and the ductility coefficient increases obviously.(2)Under low cycle reciprocating load and with the increasing of the ratio of length to width of column section,the specimens designed according to equal strength or equal section turn core zone of joint failure mechanism into beam hinge failure mechanism,and show great energy dissipation capacity and ductility.But when the ratio of length to width of column section is oversize,the ductility coefficient increases obviously.(3)The external length of reinforcement rings,external width of reinforcement rings,angle width of flange of reinforcement rings,thickness of plate of reinforcement rings have great influence on H-shaped beams to rectangular steel tubular columns with the outer reinforced diaphragms joints.When the parameter mentioned above are undersize,specimens show core zone of joint failure mechanism and seismic performance is poor.When the parameter mentioned above are suitable,Specimens show beam hinge failure mechanism and show great seismic performance.