Local displacement of core in two-layer sandwich composite structures subjected to low velocity impact

Traditional single layer sandwich structures consist of two face sheets and a core. With an additional sheet, called internal sheet in this paper, inserted into the core, a two-layer sandwich panel is then formed. Two-layer panels with polymer matrix composite laminated face sheets and a thin internal sheet subjected to low velocity impact are studied in this paper. The commercial LS-DYNA3D software is used to model and analyze the dynamic problem, and attention is focused on the local displacement of a honeycomb core under the point of impact in the conditions of various locations of the internal sheet and of different levels of impact energy. Simulated results reveal that the local displacement of the core along the direction of the impact has been decreased significantly by introducing the internal sheet into a traditional single sandwich structure and by reducing the space between the internal sheet and the impacted face sheet. This result suggests a new sandwich structure to reduce the local crash/buckling of the core under the point of the impact.