Study On Mechanical Behavior Of Cold-formed Thin-walled C Steel Composite Floor Under Longitudinal And Horizontal Forces

The cold-formed thin-walled steel structure residential system has been widely promoted and applied in recent years.However,there are few studies on the mechanical behavior of the composite floor under the longitudinal horizontal force.In this paper,the mechanical behavior of composite floor specimens under longitudinal horizontal low-cycle repeated loading is studied by experiments and finite element analysis.Mainly carried out the following work:(1)Low-cycle repeated loading tests were carried out on one cold-formed thin-walled C steel beam-concrete composite floor specimen,three cold-formed thin-walled C steel truss-concrete composite floor specimen and one cold-formed thin-walled C steel truss-ALC composite floor specimen.The influence of three parameters,namely the form of the floor beam,the layout of the shear-resistant parts and the type of the floor slab,on the mechanical performance is studied.By comparing and analyzing the hysteresis curve,skeleton curve,secant stiffness,ductility coefficient,deformation recovery ability and energy consumption of each specimen,the comprehensive evaluation of the mechanical performance of the structure was made.(2)The test data analysis shows that:(1)With the same floor slab structure and s shear-resistant parts layout,the floor beam with cold-formed thin-walled C steel beam has better performance than the floor beam with cold-formed thin-walled C steel truss in shear bearing capacity,shear stiffness and total energy consumption.But the ductility and deformation recovery performance are weak;(2)The ultimate shear bearing capacity,initial stiffness,deformation recovery ability and the integrity of composite floor can be obviously improved by placing shear-resistant parts in the specimens(3)Among the above properties,the ALC used in the slab is weaker than the concrete slab with the same condition except that it has better deformation recovery ability.And its failure process is characterized by fragmentation and shedding of the ALC slab,the brittle nature is obvious.(3)Using ABAQUS finite element software,the theoretical model of cold-formed thin-walled C-shaped steel-concrete composite floor specimen under low-cycle repeated loading is calculated,and the correctness and rationality of finite element calculation is verified by comparing the test results.(4)Using finite element software ABAQUS to analyze the parameters of the factors most likely to have great influence on the specimen.The finite element method was used to calculate the specimen model by changing the thickness and yield strength of the profiled steel plate,replacing the closed profiled steel plate,the bent profiled steel plate,and the transverse steel bar are welded at the profiled steel plate wave crest.Last,the initial stiffness,skeleton curves and stress distribution of the components were compared and analyzed.