Numerical and parametric studies on out-of-plane flexural and shear behaviour of half steel-concrete slabs

Abstract This study proposed a 3D finite element model (FEM) to investigate the out-of-plane flexural and shear behavior of half steel-concrete (Half-SC) slabs using general software ABAQUS, simplifying the headed stud to zero-length springs in three directions. The developed FEM against fifteen Half-SC slabs test results well predicted four failure modes, namely, flexural failure, shear failure, balanced failure, and interface slippage failure. Except for the specimen in interface slippage failure, the load versus midspan deflection curves had a good agreement with the test curves. It indicated that for the slabs in partial shear connection design, the interface characteristics have a sensitive effect on their mechanical behaviour. Extensive validations of FEM were conducted on the failure mechanism of the Half-SC slabs during the loading process. Parametric studies were performed with the developed FEM to investigate the influences of main parameters on the bearing capacity of the Half-SC slabs. FEA results indicated that the increasing section steel ratio and volumetric steel ratio of the tie bar enhanced the bearing capacity of the Half-SC slabs, while there was an upper limit for both steel ratios. As the shear span ratio increased, Half-SC slabs transitioned from shear failure to flexural failure, with bearing capacity decreasing significantly. The influence of the shear span ratio, section steel ratio, and volumetric steel ratio of the tie bar on the bearing capacity decreased in order of significance. Furthermore, the bearing capacity calculation method of out-of-plane flexural and shear strength was verified based on numerical studies. A unified tie-arch model covering flexural failure and shear failure was then established. Finally, the formula for calculating out-of-plane bearing capacity was proposed based on the elastic design method.