Dynamic Response of Cross Tube With Crushable Foam-Filled Cellular Core

Abstract

Abstract Thin-walled crush tubes and other axial members are often employed as energy absorbers in vehicle chassis to improve crashworthiness of front and side chassis members. Thin-walled axial crushing members are primarily used due to their high strength to weight ratios. Previous works cover extensively the study of thin-walled members under axial crushing loads. Additionally, work has been done exploring the effects of core addition to a standalone thin-walled structure. Functionally graded cellular structures are often employed to enhance energy absorption due to their high strength and stability with minimal added weight burden. Previously, investigation on the addition of composite functionally graded hexagonal extruded cores proved to increase energy absorption capacity and improve stability of the structure. The present study is a continuation of the previous work on functionally graded core material addition to thin-walled crush tubes. Additionally, this study investigated the addition of crushable foam material to the volume of the cellular structures. This study was conducted utilizing ABAQUS explicit dynamic modeling environment. The addition of graded cellular core material with crushable foam provided increased energy absorption capacity of the structure through increased structural stiffness and decreased crush stroke. The structure exhibited progressive folding/collapse mechanisms with a more global crushing response as compared to an empty tube structure. As compared to previous graded cellular core structures, the crushable foam addition promoted a more global structural response and allowed for total energy absorption before structure densification. The addition of core materials within thin-walled crush tubes have shown positive influences on energy absorbing capacity and overall performance of crush tube members.