Experimental, analytical, and fuzzy modeling for predicting the flexural capacity of flat sandwich panels

Abstract This study presents a comprehensive investigation into the load-bearing capacity of flat sandwich panels through experimental testing and analytical calculations. Wall sandwich panels with mineral wool cores and steel facings were tested. Notably, the experimental program included not only standard single-span configurations but also two-span and three-span bending schemes, for which established testing standards are currently lacking. These experiments revealed that panel behavior depends significantly on the span length and core thickness, with failure typically governed by shear deformation within the core or local instability of the facings. This research provides a new, extensive dataset specifically generated for the validation of theoretical models. Analytical calculations were performed based on elasticity theory, considering the shear compliance of the core material. Comparison between experimental and analytical results revealed a convergence of under 4% for the single-span model. However, for the two-span and three-span configurations, the error margins were 11% and 27%, respectively. In addition, a sensitivity analysis was conducted for the first time using a fuzzy set theory approach to assess the impact of uncertainties in material characteristics and sandwich geometric parameters on panel displacements. The comprehensive comparison demonstrates the need for improved theoretical models and facilitates a more adequate assessment of sandwich panel modeling results.