Advanced Thin-walled Composite Structures for Energy Absorption Applications

This article investigates the influence of adding halloysite nanoclay (HNC), montmorillonite clay (MC), alumina (Al2O3), silica (SiO2), and silicon carbide (SiC) nanofillers on the crashworthiness performance of glass/epoxy energy absorbent composite tubes. The abovementioned nanofillers were used separately at 1,2,3, and 4 wt.%. Nanofilled glass/epoxy composite specimens were fabricated using wet-wrapping process by hand lay-up. The fabricated specimens were tested under quasi-static axial compression loadings at 10 mm/min crosshead speed. Unfilled tubes (0 wt. % of nanofillers) were fabricated and tested for comparison purpose. The crush load-displacement response, initial crushing failure load (P-ip), average crushing load (P-avg), absorbed energy (U), specific energy absorption (SEA), crushing force efficiency (CFE), and spring back (SB) were determined, and the progressive crushing behavior was traced. Results indicated that the failure modes and U are highly dominated by the type and wt. % of the embedded nanofillers. The addition of HNC, MC, and Al2O3 enhances U of glass/epoxy composites during crushing process. Composites filled with 4 wt. % of HNC has the highest load carrying capacity and U compared to other tubes so they seem to be the best appropriate choice for energy absorbing elements. The addition of nano-SiO2 or nano-SiC negatively affects the crashworthiness characteristics. The overall outcomes revealed that glass/epoxy composite tubes filled with HNC, MC, and Al2O3 show outstanding energy absorption characteristics. However, specimens filled with SiO2 and SiC nanofillers are ineffective in the crashworthiness applications.