Design and Fabrication of Resilient Sandwich Composite Structures with Multi-stable Energy Absorption Core

Composite sandwich structures, while offering desirable mechanical properties such as light weight, high flexural rigidity and energy dissipation under loading, also suffer from inelastic damage accumulation under loading conditions. With a greater demand placed on composite structures to perform in extreme environmental conditions, it is necessary for composite sandwich structures to not only absorb impact, but also dissipate the impact energy without accumulating permanent damage - that is, be resilient to damage. In this paper, we present a novel sandwich core design strategy to incorporate energy absorbing core structures that rely on structural buckling to dissipate energy. These cores are printed using a stereolithography (SLA) desktop 3D printer. A parametric study to better understand the energy dissipating buckling behavior is performed using an experimentally validated finite element analysis. Using the insights provided by the computational model and experiments, recommendations are made for an optimal core design.