Research on low-velocity impact performance of polyurethane foam-filled M-type GFRP foldcore sandwich plate

The M-type GFRP (Glass Fiber Reinforced Polymer) foldcore was prepared by thermal pressing method, and was bonded with the panel to obtain the complete foldcore sandwich structure and filled the core with polyurethane foam. The influence of foam filling, impact energy and impact position on the damage mode and impact dynamic response under the low-velocity impact of GFRP M-type foldcore sandwich structure is studied through low-velocity experiment. The results show that the impact resistance of N-side impact is better than the B-side impact. Foam filling could effectively closing the gap between the N-side impact and B-side impact. In addition, foam filling could absorb about 15%-25% more energy than the empty core sandwich plate.