The impact response and failure mechanism of sandwich plates with M-type foldcore under low-velocity impact

Foldcore sandwich structure has promising applications for load-bearing, and in this study, M-type foldcore sandwiches are prepared through a molding and pressing process with fiberglass. To be specific, the sandwich structures are investigated for dynamic response and damage mechanism under low-velocity impacts with various impact positions and energy. The results show that impact position significantly affects the damage mode of the sandwich plate, the damage mode of crush fracture and collapse failure at node position can dissipate higher energy compared with tensile fracture at base position. Moreover, the impact energy shows a certain influence only when the sandwich panel is not penetrated. Besides, numerical prediction closely matches experimental results in terms of load-displacement and energy-displacement histories. Effects of geometric configuration are explored, and the results suggest that although increasing the thickness of panel and core can effectively improve the load-bearing capacity under low energy impacts, increasing the core thickness is a more effective method in lightweight design than increasing the thickness of plane. Furthermore, the impact resistance can be enhanced by selecting the appropriate platform length and narrowing the platform angle. Notably, M-type foldcore sandwich is superior to V-type foldcore sandwich and corrugated sandwich in terms of specific energy absorption.