Influence of pore geometry and distribution on buckling under micro computed tomography

Abstract

Open-cell polymeric foams are widely used for energy absorption applications due to their unique structural properties. Visualizing the compression behavior of these foams is essential for understanding their viscoelastic response and energy dissipation capabilities. This study investigates the deformation characteristics of an open-cell polyurethane foam, a prospective next-generation material for military combat helmets developed by helmet company Team Wendy. Using micro-computed tomography (CT), two foam samples are scanned at 0 % and 28–29.5 % compression to assess changes in pore geometry. Results show a 10–25 % reduction in pore volume and a 5–10 % decrease in shape uniformity upon compression. Comparative and statistical analyses reveal that initial pore volume significantly influences the sequence of cell collapse. Additionally, pore buckling order is affected by the relative porosity of the material layers, while polydispersity does not play a major role. These findings suggest that both regional density and pore volume are key factors in predicting cell buckling order, providing valuable insights into the structural characteristics that govern open-cell foam deformation under stress.