Lightweight hybrid composite sandwich structures with additively manufactured cellular cores

This study focuses on advancing sandwich structures by designing and fabricating complex two- and threedimensional cellular cores combined with Carbon Fiber Reinforced Polymer (CFRP) skins. Numerical analysis is used to investigate the effect of core design and density on the bending performance. Optimal configurations are identified and experimentally validated. Professional Fused Filament Fabrication (FFF) equipment with a heating chamber is employed for manufacturing the core samples to enhance layer cohesion and material joint stiffness. A high-performance technical polymer with a superior strength-to-weight ratio is employed to maximize structural capabilities. Hybrid sandwich structures with PEI Ultem cellular cores demonstrate stiffness and strength comparable to reference materials, outperforming foam cores while slightly trailing behind Nomex & REG; and aluminum honeycombs. In addition, the results demonstrate more efficient cell morphologies achievable through additive manufacturing technologies, surpassing the hexagonal design. This work provides valuable insights into hybrid composite materials and the potential of additive manufacturing in creating lightweight, high-performance sandwich panels.