Aluminum foam core density and geometry influences on the deformation mechanisms and energy absorption capacity of foam filled braided tubular structures in axial and transverse loading

The mechanical response of an energy absorbing device was studied experimentally by means of a custom built testing machine. Results showed that the force/displacement behavior was strongly dependent upon foam density; however after tow lockup this dependency was reduced. Axially loaded specimens utilizing circular cores reduced the total elongation to failure and maximum load by approximately 120 mm and 7 kN, respectively compared to specimens utilizing rectangular cores. Good agreement and deviation between theoretical results and experimental tests for specimens with low and high density cores were observed with an error of 3.03% and 16.45%, respectively. Significant tensile loads and to a lesser extent bending within the braided tube occurred during transverse loading. Specimens containing circular foam cores were found to be more efficient in SEA, approximately 2 kJ/kg greater than rectangular cores. A 22% reduction in FE was determined for specimens containing rectangular cores compared to circular cores