Crashworthiness performance of bio-inspired BCC lattice structures: Comparative evaluation of aluminum, neat jute epoxy, and hybrid glass/jute epoxy composite structures

The growing demand for lightweight and sustainable crashworthy structures in the automotive sector, especially for electric vehicles, requires new material geometry combinations that balance safety and efficiency. This study investigates the crashworthiness performance of bio-inspired Body-Centered Cubic (BCC) lattice structures fabricated from aluminum, neat jute/epoxy, and hybrid glass/jute/epoxy composites. The objective was to evaluate how material composition and geometric variation influence crushing behavior to identify lightweight and sustainable alternatives for energy absorption applications. Two configurations were developed for each material: a solid center ring (BCC-A) design and a cut ring (BCC-B) design. Composite laminates were fabricated using the resin transfer molding (RTM) process, and the desired BCC lattice configurations were shaped using waterjet cutting. Quasi-static compression tests were conducted to evaluate energy absorption (EA), specific energy absorption (SEA), initial peak force (IPF), crush force efficiency (CFE), and failure mechanisms. The results showed that aluminum structures achieved the highest SEA values in the range of 0.38–0.41 J/g; however, their high IPF and weight values limited their use as lightweight crash structures. Neat jute composites exhibited brittle failure, characterized by the lowest SEA values and distinct brittle and catastrophic fractures. However, hybrid composites demonstrated superior crash performance among the composites, with the cut-ring hybrid (BCC-B-HD) achieving the highest SEA among composites at 0.29 J/g, approximately 26 % higher than the uncut hybrid. The cut-ring modification was especially effective in enhancing CFE by promoting progressive collapse. These results point out the benefit of combining hybridization with bio-inspired geometry to create lightweight and sustainable crashworthy structures in electric vehicle crash zones and battery protection systems, where weight reduction and energy absorption must be balanced.