Energy Absorption of Axially Loaded Thin-Walled Pressurized Cylinders

Abstract

Abstract Our goal in this paper is to experimentally measure the axial load and energy absorption capacity of thin-walled aluminum cylinders subjected to internal pressures. For this purpose and to achieve a high level of accuracy in manufacturing the thin-walled cylinders, we used regular soda cans as the cylindrical specimens. The specimens’ dimensions were selected based on attaining a large radius to thickness ratio (r/t) of 340 to minimize weight and also maintain a low axial length to radius ratio (L/r) of 2.6 to mitigate global buckling. Each specimen was compressed quasistatically while maintaining constant internal pressure with the use of input and output pressure regulators we designed and built for this purpose. One of our goals in this experiment was to better understand the energy absorption capability of such a lightweight structure and to study the failure modes of local buckling under different internal pressures. We observed that the local buckling mode switches from non-axisymmetric folds (diamond mode) to axisymmetric folds (ring mode) at a critical internal pressure. We also presented a comparison between pressurized aluminum thin-walled cylinders to steel cylinders and we found that aluminum made cylinders outperform their steel counterparts when compared by equivalent masses. Applications of this study vary across a wide range of industries, with the most appealing being automotive and aerospace.