Experimental Study And Finite Element Analysis Of Steel Frames With T-stub Connections Using Slotted Holes

According to the existing experimental study shows that steel T-stub connections with slotted holes has excellent energy dissipation capacity,high ductility and so on.In order to understand the effect of new-type steel T-stub connections on the overall mechanical performance of the steel frame,and obtain the new type connections of steel frame in different stages of the mechanical behavior,force mechanism and failure mode.The following work has been completed:Firstly,quasi-static test research of a full-scale steel frames with slotted holes T-stub connections for slotted sizes is 4mm.Secondly,the ABAQUS finite element analysis software is used to simulate the three-dimensional solid model of the test framework frame,to study of the stress state,deformation characteristics and stress distribution of the new type of steel frame at each stage deeply.Thirdly,a finite element model of steel frame connected by ordinary steel T-stub connection(T-0 frame)and three finite element models of steel frame connected by new-type steel T-stub connections with different sizes of slotted holes(T-2 frame,T-4 frame and T-6 frame)are established by ABAQUS to study the effect of different slotted hole size on the mechanical properties of new type steel frame.Through the related research of this paper,the main conclusions are shown as follow:(1)The hysteresis curve of the new type connections of steel frame is spindle-shaped.The shape is full,and there is no "pinching" phenomenon.(2)The rotation angle of the steel frame with T-stub connection is composed mostly of T-stub steel slip reaming and plastic deformation.The new connection has good rotation capacity and better link reliability in the actual steel frame structure.(3)The new type connections of steel frame can dissipate part of the energy through the sliding of connections during the horizontal force process,and the connections slip can also delay the production of the plastic hinge of the steel beam,so as to achieve the purpose of protecting the beam member.And the larger the effective sliding distance of the bolt,the smaller of the beam stress with slower growth and the development of plastic is also slower.(4)Compared with the ordinary steel T-stub connections frame(T-0 framework),under the circumstances of not changing beam column section size of steel frame connected by steel T-stub with slotted holes,through selecting different expanding size to achieve different performance of steel frame,and this may provide possibility and convenience to performance design of base on displacement of steel frame.(5)Compared with the ordinary steel T-stub connections frame,the overall ductility of the steel frame with slotted holes of T-2-T-6 is obviously increased,and the overall ductility of the steel frame is better with the increase of the hole' size.(6)In comparison with the ordinary T-stub connection steel frame(T-0 frame),the slotted holes T-stub connections steel frame(T-2 to T-6 frame)can significantly reduce the overturning moment of the frame.However,the slotted holes size of the T-stub steel web is not the control parameter of the overturning moment of the steel frame,but depends on the effective sliding distance of the bolt,that is to say,the larger the effective sliding distance of the bolt of the steel frame,the smaller the overturning moment of the frame.In addition to reducing the overturning moment,reasonable hole size can reduce the base shear of the steel frame with new type of connection.