Experimental investigation of mechanical properties of Kevlar fiber composite sandwich panel with truss core reinforced by nano‐SiO₂

Abstract The present paper addresses the flexural and compressive properties of Kevlar fiber reinforced sandwich panels with a truss core reinforced by nano‐SiO₂. For this purpose, a polymer composite sandwich panel with a truss core made of Kevlar fiber and resin epoxy has been fabricated in this experiment using the vacuum‐assisted resin transfer molding method. Afterward, polyurethane foam was injected into the empty space of the sandwich panel. In order to determine the flexural and compressive strength of the composite structures, the sandwich panels have been subjected to three‐point bending and compressive load. The main findings were: adding 1 and 3 wt% of nano‐SiO₂ into the Kevlar fiber had the most desirable effects on the enhancement of flexural and compressive strength of the sandwich panels, polyurethane foam has improved the mechanical strength of sandwich panels, and the novel lozenge core can well postpone the buckling and failure of the composite sandwich structures.