Flexural Performance Evaluation of Multi‐Axial Fiber Sandwich Panels Reinforced With Multi‐Cavity Pultruded Profile Cores

ABSTRACT This study investigates the flexural performance of a novel composite sandwich panel incorporating multi‐cavity pultruded profile cores and multi‐axial glass fiber reinforced polymer (GFRP) face‐sheets and webs. The influence of fiber reinforcement, angle and number of fiber layers on the flexural property of the sandwich panels was systematically evaluated through four‐point bending tests. The experiments compared failure modes, load–displacement responses, and load–strain behaviors of sandwich panels with different core configurations. Experimental results revealed that sandwich panels reinforced with foam core predominantly failed by top face‐sheet compression, with fiber reinforcement offering mild improvements in ultimate load and displacement. In contrast, sandwich panels reinforced with pultruded profile cores exhibited core shear and buckling of face‐sheets, and their ultimate load and displacement were significantly improved. Furthermore, a theoretical model was proposed, and the predicted results closely matched the experimental results.