| The research group draws on the concept of ring beams and structural columns in masonry structures and proposes a weak frame-light steel composite wall prefabricated housing system.This system mainly consists of a weak steel frame,internal lightweight steel composite walls,and composite floor slabs.The topic of this paper is based on the prefabricated composite floor slab in this new structural system.It conducts an in-depth study on the flexural performance of the assembled cold-formed thin-walled steel-perlite concrete composite floor slab,aiming to improve the research on the load-bearing performance of the composite floor slab in this system and provide reliable design basis for engineering applications.(1)The numerical simulation analysis of the previously conducted composite floor slab tests by the research group was carried out using ABAQUS finite element software to verify the correctness and reliability of the modeling method in this paper.(2)A finite element model of the assembled composite floor slab was established,and the influence of parameters such as floor panel material,composite floor slab span,number of connection plate screws,connection plate thickness,number of bolts,connection type,size of ring beam section,and steel material properties on the flexural performance of the assembled composite floor slab was analyzed.The finite element results show that: 1)The larger the span of the assembled composite floor slab,the poorer its flexural performance.2)With the increase in the number of self-tapping screws,the ultimate flexural load-carrying capacity and elastic flexural stiffness of the assembled composite floor slab also increase.In order to reduce the influence of eccentricity on the self-tapping screw group and improve the safety reserve of the assembled composite floor slab,the number of self-tapping screws is set to 9.3)The thicker the connection plate,the stronger the flexural performance of the assembled composite floor slab.In order to avoid the compression damage of the connection plate,the thickness of the connection plate should not be too small,and it is set to 5～6mm.4)The assembled composite floor slab connected by bolts has higher ultimate load-carrying capacity than the ones connected by welding or integral stiffening rib connections.Moreover,bolt connections are convenient for construction,cause less environmental pollution,and are more in line with the concept of prefabricated buildings.Therefore,bolt connections are recommended.5)Increasing the thickness of the flange and web of the H-shaped ring beam and the strength of the steel can improve the flexural performance of the assembled composite floor slab.Considering that the H-shaped ring beam section should not be too small,the steel strength is set to 235 Mpa,the flange thickness is set to 8～10mm,and the web thickness is set to 5～7mm.(3)A simplified calculation model of the T-shaped composite beam for the new assembled composite floor slab was proposed and validated through finite element software.Based on the calculation theory of equivalent flexural stiffness and ultimate load-carrying capacity for coldformed thin-walled steel composite floor slabs,correction factors considering the influence of composite floor slab span,number of self-tapping screws in connection plates,and connection plate thickness were obtained through numerical fitting.Based on this,the calculation formulas for the equivalent flexural stiffness and ultimate load-carrying capacity of the assembled composite floor slab were proposed. |
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