Study On Mechanical Properties Of Top And Seat Angle With Stiffener Connection

Steel frame top and seat angle with stiffener connection is a new form which is evolved from traditional top and seat angle connection by welding top and seat angle stiffener.Compared with traditional top and seat angle connection,this new type of connection can greatly increase the stiffness and bearing capacity of structure without suffering the loss of structural ductility.This paper investigates the behavior of top and seat angle with stiffener connection through the way of experimental study and finite element modeling.Four groups of static load test and three groups of cyclic load test were taken place to obtain the failure modes and bending moment-rotation curve of each specimen,and evaluate the stiffness and bearing capacity of this connection.Finite element models are established by ABAQUS and verified the results with test.In order to study the influential factors of the static behavior of steel frame top and seat angle with stiffener connection,a large number of nonlinear finite element analysis were done.The influential factors include the thickness of top and seat angle and stiffener,the shape of stiffener,the size of angle steel,and the pre-tightening force of high-strength bolt.Through experimental study and finite element modeling,this paper obtained the following conclusions:(1)Top and seat angle with stiffener connection possesses good ductility and appreciable initial rotation stiffness and bearing capacity.(2)The hysteresis curve of top and seat angle with stiffener connection under cyclic load is full and alike to a spindle.The connection has good seismic effect.(3)Increasing angle thickness can greatly improve initial rotation stiffness and bearing capacity of the connection.When the angle thickness is small,increasing 2mm can make the initial rotation stiffness increased by more than 10%.The initial rotation stiffness and bearing capacity are different if the angle stiffener shape changed.Triangle is suitable for the stiffener shape,and two right-angle sides are respectively equal to the interior length of two limbs of angle steel.