Dynamic and Quasi-Static Plastic Behavior of Single and Nested Thin-Walled Square Tubes Under Lateral Loading

This paper investigates the dynamic and quasi-static plastic behavior of single and nested mild steel square tubes under lateral loadings experimentally and numerically. The dynamic experimental tests are carried out using a gas gun and the dynamic force-time responses are measured with a load cell. Also, the quasi-static experimental tests are performed in a universal test machine. The dynamic experimental tests are also simulated with the finite element software Abaqus. Furthermore, the square tubes’ combinations in the nested systems are investigated in the present work. It is revealed that the amount of peak load decreases significantly when the form of the single tube changes from square to lozenge. It is also observed that in the nested tube structures, by changing each of the outer or inner tubes or both of them from the square form to lozenge one, the amount of peak load decreases meanwhile the energy absorption capacity decreases too, which is not desirable for energy absorbers. By comparing the impact results of both the single and nested square tubes which have the same mass, it can result that the nested square tubes behave better as energy absorbers compared with the single tubes.