Research On The In-plane Of Cold-formed Thin-walled Steel-Gypsum Based Self-leveling Mortar Composite Floor

The cold-formed thin-walled steel structure residence, evolved from wood structure, is a lightweight frame structure system, the cold-formed thin-walled steel-gypsum based self-leveling mortar(CFSGS) composite floor is a new kind of composite floor. In order to the further development of light steel residential system, and promoting the process of residential industrialization, this paper make a deep research from two aspects of experimental research and theoretical analyses, the main contents of this research are as follows:(1) To research the in-plane shear resistance capacity, in-plane stiffness, failure mode and horizontal load transfer mechanism of the CFSGS composite floor, a low-reversed cyclic loading test was carried out.(2) Researching the effects of screw fastening on the in-plane shear capacity, in-plane stiffness of the CFSGS composite floor, the screw push-out specimens, same structure as composite floor, is established to carry out the vertical monotonic loading tests. Test results show that the damage mode of screw fastening agrees well with the composite floor test results; single screw shear resistance capacity and the screw slip values in different stages for calculated loads were determined. Meanwhile, referring to Japanese timberwork design specification on shear flow simplified analysis method to propose the CFSGS composite floor in-plane shear resistance capacity calculation method.(3) Through the analysis of CFSGS composite floor on in-plane force bearing status, a simply supported wide flange-deep beam model under the action of uniformly distributed load is put forward. And based on the horizontal deflection results of wooden floor from the IBC-2012 code and the single screw slip values in different stages for calculated loads, the mid-span horizontal displacement calculation formula of the CFSGS composite floor is derived.(4) Through studying horizontal load transfer mechanism of the cold-formed thin-walled steel structure residence on lateral force resistant system(LFRS), the composite spring model is established to analyses the influence of different floor stiffness on the lateral load distribution among shear wall, which is verified the correctness and applicability.