Mechanical Properties Of Profiled Steel Sheeting And Lightweight Aggregate Concrete Composite Slabs Based On Partial Combination Theory

The profiled steel sheeting and lightweight aggregate concrete composite slabs not only have the advantages of ordinary concrete composite slabs,but also has the characteristics of light weight and environmental protection.The profiled steel sheeting and lightweight aggregate concrete achieves synergistic work and give full play to their respective advantages through the combination of interfaces.This combination can be divided into three types,namely full combination,partial combination and no combination.The calculation method of the bearing capacity given in the current design specifications and construction regulations of composite slabs in China is based on the full combination theory.However,in actual engineering,the composite slab is more in a state of partial combination.It is more practical to study the mechanical properties of composite slabs based on partial combination theory.Therefore,based on the partial combination theory to study the mechanical properties of the profiled steel sheeting and lightweight aggregate concrete composite slab and establish the calculation method of capacity and finite element calculation model have theoretical significance and engineering value.In this paper,the full-size static loading experiment on six profiled steel sheeting and lightweight aggregate concrete composite slabs are conducted.Three specimens are equipped with end studs,while the other three are not equipped with end studs.The failure processes of the composite slabs are recorded,and the failure modes of the composite slabs with different constructions are compared.Analyze the bending moment-span deflection curve,the bending moment-end slip curve and the strain variation law of the composite slabs.It shows that the three composite slabs without end studs suffer longitudinal shear failure.The other three composite slabs with end studs are subjected to bending failure.The bearing capacity of the non-studs composite slabs is calculated by partial shear connection method,and the design shear-bond stress valueτ_u,Rd of this type of composite slab is 0.146 MPa.An improved calculation method of bearing capacity based on partial combination for composite slab with end studs is proposed.This paper uses ANSYS for finite element simulation.Based on the experiment of six full-size composite slabs,the finite element model of the partially combined composite slab is established with end studs introduced.Use contact pairs to simulate the combination between the interface.The simulation results are consistent with the experiment results.Extend samples through the model to study the effects of steel sheeting strength,steel sheeting thickness and slab thickness on the bearing capacity of the composite slab.It is recommended to increase the thickness of the steel sheeting in engineering practice to improve the bearing capacity of the composite slab.The modal analysis is carried out to study the dynamic characteristics of the composite slab,includes its natural frequency and vibration mode.Compare the finite element simulation results with the theoretical calculation results and the two are highly consistent.Moreover,the natural vibration frequency of the composite board meets the specification requirements.The effects of steel sheeting thickness,slab thickness and slab span on the dynamic characteristics of the composite slab are studied by finite element modal analysis.This can provide reference for engineering practice.