Energy absorption of multicell thin walled structures filled with polyurethane infiltrated open cell aluminum foam.

Compact energy absorbers are needed to protect testing electronics in high-impact systems with limited installation space. Unlike previous studies that mainly examined tubular or fully filled configurations, this work investigates selective filling within a 12-mm-high multi-cell thin-walled structure. Partial and full configurations using aluminum foam (AF) and polyurethane-infiltrated aluminum foam (AF/PU) were evaluated through quasi-static compression, dynamic impact testing, finite element simulations, and theoretical analysis. Comparisons among five configurations and three wall thicknesses showed that filler distribution affected the balance between crushing resistance and effective crushing stroke. The partially filled AF/PU structure with a 1.2 mm wall thickness exhibited the best overall performance, absorbing 895.41 J quasi-statically and 984.40 J dynamically, with a volumetric specific energy absorption of 21.32 J/cm3 and crushing force efficiency of 0.84. Compared with full filling, selective AF/PU filling uses less filler while retaining greater deformation space, providing a practical strategy for compact impact protection.