Experimental Analysis of Energy Absorption and Deformation of Foam-Filled Thin-Walled Tubes With Various Section Geometry

In the present research, effects of foam filling on the deformation and energy absorption capacity of thin-walled aluminum tubes with various section shapes (circular, square, triangular) and 2 mm thickness, are investigated experimentally. The tubes were the same volume, height, average section area and material and were subjected to axial dynamic loading. Poly Styrene (grade 2), Polyurethane, Polyethylene and Unolit foams were used in experiments. The experiments were carried out by drop Hammer apparatus in Bu-Ali Sina University. The results show that the section geometry and foam filling have a considerable effect on the energy absorption capacity, mean crushing load and maximum load. Investigating both parameters including section geometry and foam filling showed that circular tubes have the greatest energy absorption capacity, mean crushing load and maximum load among all various sections; furthermore, Unolit-filled tubes have the best performance among the foam-filled ones. On the other hand, in the same conditions, triangular tubes and Polyethylene-filled tubes have the least energy absorption capacity, mean crushing load and maximum load among the tested specimens. It was concluded that the circular tubes filled by Unolit foam have the most energy absorption capacity and mean crushing load, while the triangular tubes filled by Polyethylene foam have the least energy absorption capacity and mean crushing load. A remarkable improvement in energy absorption characteristics of the specimens was observed because of the foam filling. In addition, the foam affects the folding paradigm.