Low-velocity impact behavior of tooth plate glass fiber/polyurethane foam core sandwich beams

A new family of tooth plate-glass fiber/polyurethane (TP-GF/PU) foam core sandwich beams consisted of TP-GF facesheets and a PU foam core were studied, in which tooth plates were connected with foam core through tooth nails. TP-GF/PU foam core sandwich beams were fabricated by a vacuum-assisted resin infusion process. The aim of this article is to investigate the impact response and impact damage of TP-GF/PU foam core sandwich beams with various foam densities and fiber thickness under low velocity impact tests. Double cantilever tests were also conducted to investigate the interfacial properties of TP-GF/PU foam core sandwich beams. An analytical model was used to calculate the strain energy release rate of TP-GF/PU foam core sandwich beams. The test results show that, under the energy impact of 22 J, 33 J and 44 J, the maximum contact force of the sandwich beam with a density of 150 kg/m³ is 31.2%, 48.6% and 33.3% higher than that of the ordinary sandwich beams, respectively. The absorbed energy is 17.2%, 11.3%, 15.5% higher than that of the ordinary sandwich beams, respectively. The maximum contact force increased with the increase of foam core density and impact energy. The main damage modes for TP-GF/PU with low foam density are face sheet bending. The strain energy release rate of TP-GF/PU specimen increase with the increase of the foam density.