Static Energy Absorption Capacity of Graphite-Epoxy Tubes

Abstract

This paper examines the energy absorption capacity of Akzo Nobel Fortafil 50k carbon fiber composite tubular specimens crushed axially in a quasi-static fashion. The towpreg form of this material, obtained from Thiokol, was filamentwound to produce specimens. Circular and square tubular specimens with ± 45° and ± 45°/0° fiber orientation schemes were studied. As a baseline comparison, similar tubular specimens were fabricated using T300 12k fiber, an aerospace standard. The fundamental issue was to study the energy absorption capacity of the lower cost 50k material in comparison to the 12k material, and to determine the influence of specimen geometry and fiber orientation schemes on the energy absorption capacity. It can be concluded that, overall, the specimens made of the 50k material had lower average crush loads and specific energy absorptions (SEAs) than the specimens made of 12k material. The load ratios for the 50k specimens were slightly higher than for the 12k specimens. It can be also concluded that for both the 12k and 50k material the square specimens had lower SEAs than the circular specimens. The presence of the 0° fibers had some influence on the SEAs of the circular 50k specimens and some influence on the load ratios of the circular 12k specimens, but otherwise they had little influence. The work is important and timely because of the current search for more cost-effective rawmaterial forms and the need to understand their response characteristics.