Core modifications of sandwich panels fabricated by vacuum-assisted resin transfer molding

Composite sandwich panels with high stiffness to weight ratios are mostly used in the transportation, aerospace, and marine structures. In this study, the possibility of manufacturing the sandwich panels by vacuum-assisted resin transfer molding without using the distribution media is experimentally investigated. These structures are comprised of E-glass fiber/polyester resin face sheets and a rigid polyvinyl chloride foam core. In order to facilitate the fabrication of sandwich panels by vacuum-assisted resin transfer molding, six different hole patterns are conducted on the foam core, then the effects of each one on the manufacturing parameters and mechanical properties were studied. Results show that the mold filling time decreases up to 40%, and bending critical load and yield absorbed energy increase up to 38% and 100%, respectively. However, the specimens' weight increases 3.6% at most. Moreover, some enhancements are seen in debond critical load and fracture toughness.