Test And Analysis Of Bearing Capacity Oif Cold Formed Steel Beam-OSB Composite Floor

As a new development direction of residential construction,light steel structure has many advantages such as lightweight,high-strength,convenient construction,no wet operation and short construction period.It has been widely used in Low-rise buildings.Oriented strand board(referred to as OSB board)and deck are light and uniform,easy to be processed,energy saving and environmental protection,and are commonly used in the construction industry.The research objects of this paper include four kinds: a double-jacketed floor beam made of two cold-formed thin-walled C-shaped steels(DB),a double-jacketed floor beam(DOB)consisting of two cold-formed thin-walled C section steel intermediate clamp OSB panel,a composite floor(SOF)joined by self-tapping screws with double-jacketed floor beam and an OSB panel,and a composite floor(SODF)joined by self-tapping screws from double-jacketed beam,OSB panel and deck.In this paper,full-scale static load tests under uniform load of the above two types of floor beam DB,DOB and two types of composite floors SOF and SODF are carried out.The test phenomenon,damage mode,ultimate bearing capacity,mid-span deflection and the strain values at important measure points of different specimens under different loads are revealed from tests.The test results show that the failure modes of the double-jacketed floor beam(DB)and DOB are local buckling at midspan of the beam,and the OSB panel in DOB makes no effort to the bearing capacity and stiffness of composite floor.Because the OSB panel on the doublejacketed floor beam is not an integral part and the deck is integrally arranged,the stiffness and ultimate bearing capacity of the SOF composite floor are limitedly increased compared to the double-jacketed floor beam,while the SODF composite slab makes an obvious increase.Based on different types of double-jacketed floor beam and composite floor,finite element models were established,analized and compared by using ABAQUS software in this paper.The analysis results of the ultimate bearing capacity,typical damage characteristics and mid-span deflection are basically consistent with the experimental data.Meanwhile,correctness and rationality of the finite element modeling method are proved.In addition,the results of finite element analysis show that when increase the thickness of C section steel,deck and OSB panel,or reduce distance between screws,the load-bearing capacity and rigidity of the composite floor are improved.In this paper,the failure modes,typical damage characteristics,and mid-span deflection changes of four types of components are obtained through the static load test and finite element analysis of two types of double-jacketed floor beams and composite floors.These provide reference and basis to similar and related research and engineering applications.