Flexural behaviour of cross-stiffened corrugated steel-concrete composite slabs: Experimental investigation and neuro-fuzzy prediction

Composite floor systems comprising profiled steel sheeting and cast-in-place concrete are widely adopted in modern high-rise construction owing to their superior strength-to-weight ratio, structural efficiency, and rapid construction capability. Accurate prediction of their flexural behaviour is essential for achieving safe and economical structural design. This study proposes a modified cross-stiffened corrugated steel–concrete composite slab system intended to enhance flexural strength, stiffness, and interfacial interaction performance. A comprehensive experimental parametric investigation was conducted to evaluate the effects of deck slab thickness, span-to-depth ratio, boundary conditions, and loading conditions on the central deflection and interfacial slip behaviour of the proposed composite slabs. Experimental results revealed that the incorporation of transverse cross-stiffeners substantially improved the load-carrying capacity and flexural stiffness while significantly reducing interfacial end slip compared with conventional profiled deck systems, without inducing local instability. To establish an accurate and computationally efficient predictive framework, the experimental database was employed to develop an Adaptive Neuro-Fuzzy Inference System (ANFIS) model for predicting deflection, slip, and ultimate load capacity. The developed model demonstrated excellent predictive capability, achieving a coefficient of determination (R²) of 0.97 and root mean square error (RMSE) values below 0.27. Furthermore, SHAP (SHapley Additive exPlanations) analysis identified deck slab thickness and span-to-depth ratio as the dominant parameters governing structural performance, while partial dependence analysis highlighted their nonlinear interactive effects on the response characteristics. The proposed experimental–computational framework provides an interpretable and reliable approach for the design optimisation and performance prediction of lightweight steel–concrete composite flooring systems, contributing to the advancement of efficient and sustainable composite construction technologies.