Crashworthiness Performance of Stiffened Foam-filled Tapered Structures under Axial and Oblique Dynamic Loads

Abstract

This paper aims to explore crashworthiness performance of new designed foamfilled tapered structures under axial and oblique impact load conditions. The structures consisted of inner and outer tapered tubes connected together by four stiffening plates. They also included square, hexagonal, octagonal, decagonal and circular cross-sectional shapes with different ratios of a/b (ratio of the inner tube side length to the outer tube one). The ratio of a/b was assumed to be 0, 0.25, 0.5, 0.75 and 1. Crashworthiness criteria of specific energy absorption (SEA), peak collapse force (Fmax) and crash force efficiency (CFE) were obtained for these structures using the experimentally validated model in LS-DYNA. Based on the numerical results, semi-foam filled structures (i.e. those with the ratio of a/b=0.5) demonstrated greater crashworthiness performance than foam filled single-cell ones. Furthermore, according to the TOPSIS calculations, cross sectional shape of decagonal was found to be an outstanding potential profile for the automobile structural components.

Crashworthiness Analysis of Octagonal-Inner Double Tube with different thickness under Off-Axis Oblique Load

“…SEA is calculated for determining energy absorption capacity of the structures, where SEA is defined from energy absorption (EA) divided by the total mass of structure (m). A suitable structure should have higher value of SEA [23].…”

“…is the maximum displacement that rigid floor collapses a structure, is the rigid floor displacement and is variation of force versus displacement [23].…”

“…This indicator tends to decrease for sake of vehicle safety. A suitable structure should have less value of maximum force [23].…”

“…Mean force is the ratio of the total energy absorption from the tubes to the effective stroke length ( ). In order to get best value of CFE, it should be equal to 100% [23]. folded size during crush looks different due to thickness of structures.…”

Crashworthiness performance of concentric structures with different cross-sectional shapes under multiple loading conditions

“…Filling the thin-walled tubes with light weight materials like aluminum, polymeric and polyurethane foams, 24–30 honeycombs 31,32 and composites 33–35 is also another way to enhance the crushing performance. However, based on an investigation performed by Chenand Wierzbicki, 24 multi-cell structures absorb 15% greater energy than the single-cell ones.…”