Numerical and Theoretical Study on the Vertical Shear Behavior of a Novel Multi-Ribbed Profiled Steel Sheeting-Concrete Composite Slab in the Construction Stage

Current studies on large-span structural components have largely emphasized flexural performance, whereas multi-ribbed profiled steel sheeting-concrete composite slabs may be prone to inclined-section shear failure in the construction stage, particularly at small shear-span ratios. To ensure that the vertical shear capacity of such composite slabs satisfies construction-stage requirements, a numerical model validated against experimental evidence was employed. A systematic parametric study was conducted to clarify the influence of key structural parameters and the shear-span ratio on the vertical shear resistance. On this basis, a calculation method for the vertical shear capacity was proposed based on the strength-equivalence principle and verified against numerical results. The results indicate that the inclined-section shear failure of multi-ribbed profiled steel sheeting-concrete composite slabs develops through four characteristic stages, the shear-span ratio governs the transition of failure mode, and slabs with a rib height of h = 150 mm exhibit a pronounced shear-dominated failure when the shear-span ratio is less than 2. Increasing the rib inclination angle degrades the composite interaction between the profiled steel sheeting and concrete, whereas increasing the sheeting thickness and slab depth enhances the load-bearing capacity and stiffness, and longitudinal reinforcement benefits the internal stress redistribution of concrete. A vertical shear capacity model was formulated for the novel multi-ribbed profiled steel-concrete composite slab and verified against numerical results. The research helps to bridge the gap in studies on the vertical shear performance of multi-ribbed profiled steel-concrete composite slabs and offers design guidance for vertical shear checks of composite slabs in the temporary construction stage.