The present paper addresses the flexural and compressive properties of Kevlar fiber reinforced sandwich panels with a truss core reinforced by nano-SiO 2 . 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-SiO 2 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.

The present research has addressed the flexural and compressive strength of Kevlar fiber composite sandwich panels with novel lattice core, experimentally and numerically. The composite sandwich panels and corrugated cores have been made using the vacuum-assisted resin transfer molding method. Afterward, compressive and three-point bending loads were applied to the composite sandwich panels to determine mechanical performance during structural deformation. Scanning electron microscopy has been conducted on the specimens to evaluate the Kevlar-fiber distribution. In order to evaluate the experimental results, the corresponding testing process has been numerically simulated through finite element analysis. It has been figured out that the simulated model can predict the force–displacement response of the considered sandwich panels under bending and compressive loads. Finally, the effect of polyurethane foam on the composite sandwich panel's mechanical strength and energy absorption capacity has been investigated.