Research On Mechanical Behavior Of Steel Frame Connected By Steel T-stub With Slotted Holes

This paper presents a study on the mechanical performance of steel frame connected by steel T-stub with slotted holes.The following work has been completed:Firstly,according to the test results of the steel T-stub connections,the model of restoring force is established,and its accuracy is proved by comparing with test data.Secondly,the hysteretic performance of the new-type steel T-stub connections with slotted holes is simulated by the connector elements(Multi-Linear Plastic)in Sap2000,and the accuracy is proved by comparing with test data.Thirdly,based on the connector elements which has been verified,the Pushover analysis and elastoplastic time-history analysis(El-Centro waves,Taft waves)are carried out for two structures with different aspect ratios(model one:two-span and six-storey with the aspect ratio of 1.75:1,model two:three-span and eleven-storey with the aspect ratio of 2.14:1)at different seismic intensity and performance level,and the connection types of structures includes three new-type steel T-stub' connections with different sizes of slotted holes,an ordinary steel T-stub connection and a rigid connection.Through the research of this paper,the main conclusions are shown as follow:(1)The given model of restoring force(ordinary steel T-stub connection and steel T-stub connection with slotted holes)possesses high accuracy and practicability.(2)The connector element of MultiLinear Plastic with reasonable parameter settings can simulate the hysteretic performance of the steel T-stub connection accurately.(3)In comparison with the rigid steel frame,the steel frame with T-stub connection can dissipate the seismic energy through the nodes slip and plastic deformation,so as to protect thedevelopment of plastic in frame beam components.And the plastic development degree of the beam reduces with the increase of slotted hole's size,which it is of great importance for the repair of steel frame after the earthquake.(4)In comparison with the rigid steel frame,the steel frame with T-stub connection can reduce the base shear,increase the ductility and the lateral shift(top drift,rotation angle of each floor)of steel frame considerably.And such effect will be more obvious with the increasing of aspect ratio,the size of slotted holes,fortification intensity and performance requirements.(5)The second-order effect should be considered in the seismic response analysis of the steel frame with steel T-stub connections,(especially for steel frame of the steel T-stub connections with slotted hole),and the adverse impact of second-order effect can be ameliorated through setting the size of slotted hole reasonably.(6)The results of this study can provide new ideas and reference for the design of steel frame based on the seismic performance-based design.