Research On Shear Performance Of Strengthed Self-drillng Screw Connections And Experimental Study On Seismic Performance Of Composite Wall

The cold-formed steel houses have the advantages of green and environmental protection,light weight of structure,short construction period,and favorable industrial production.They have been widely used at home and abroad,and cold-formed steel composite walls are used as such residential systems.The main load-bearing unit has become a hot spot for scholars from all over the world.The common cold-formed steel composite wall is made up of steel columns,U-shaped rails and wall panels connected by self-tapping screws.It has been found through research that the conventional failure mode of this type of wall is the rupture of the cladding panel at the nail hole,which causes the panel to lose the " diaphragms effect " and the entire wall is destroyed.In order to enhance the weak parts of the wall and make the cover panel fully play its role,the research team conducted the test of the screw joints and the shear performance of the strengthed self-drillng screw cold-formed steel composite wall according to the research idea from the partial to the whole.(1)For the self-drillng screw connection test under monotonic load,a total of 27 test pieces were designed by orthogonal design.From the panel type,thickness,column thickness,screw diameter,presence or absence of steel strip reinforcement and steel strip thickness,the impact on the mechanical properties of the test piece is considered.(2)For the self-drillng screw connection test under cyclic loading,a total of 14 test specimens were designed.During the test,the loading process and failure phenomenon of the test piece were recorded in detail,and the influence of different factors on the bearing capacity,stiffness,energy consumption and ductility of the test piece was analyzed.(3)Based on the self-drillng screw connection test,the shear resistance test of the steel strip reinforced cold-formed steel composite wall was carried out.In this test,a total of 3 test pieces were designed.HS-140-A is a conventional test piece.As a test reference,the HS-140-B wall test piece will be along the column direction based on the test piece HS-14-A.The screw holes are used to strengthen the steel strip;on the basis of the test piece HS-14-A,the HS-140-C wall test piece is reinforced with the steel hole along the screw hole at the panel joint.According to the test data,the influence of steel strip reinforcement on the bearing capacity,stiffness,energy consumption and ductility of the specimen was analyzed.And compare and analyze the influence of different steel strip reinforcement methods on the mechanical properties of the test piece.