Impact characteristic and energy absorption of auxetic foam-filled square tubes

Abstract

Auxetic materials have recently been gaining popularity within the research community due to their enhanced mechanical properties, particularly energy absorption performances. Unlike conventional materials, they exhibit a negative Poisson's ratio when subjected to a uniaxial loading. This present research experimentally and numerically investigates the crush response and energy absorption performances of auxetic foam-filled square tubes under axial loading. For comparison, the crush response and energy absorption of empty and conventional foam-filled squares tubes have also been examined with respect to deformation modes and force displacement curve. Standard compression tests were conducted on a series number of thin-walled tube samples. In addition to this, the fabrication process of conventional and auxetic foam has also been described in this project report. An additional compression test on conventional and auxetic foam has also been conducted to observe the behavior of foam itself. It is evident that the auxetic foam-filled square tubes are superior to empty and conventional foam-filled square tubes in terms of energy absorption capacity. It shows that such tube is preferable as an impact energy absorber due to their ability to withstand axial loads effectively. Furthermore, it is found that the load capacity increases as the crush length increases. Parametric study shows energy absorption increases as aspect ratio increases whereas energy absorption decreases with increasing slenderness ratio. The primary outcome of this study is design information for the use of auxetic foam-filled square tubes as energy absorbers where impact loading is expected particularly in crashworthiness applications.