Quasi-static, impact and energy absorption of internally nested tubes subjected to lateral loading

This paper presents the responses of nested tube systems under quasi-static and dynamic lateral loading. Nested systems in the form of short internally stacked tubes were proposed as energy absorbing structures for applications that have limited crush zones. Three configurations of nested tube systems were experimentally analysed in this paper. The crush behaviour and energy absorbing responses of these systems under various loading conditions were presented and discussed. It was found that the quasi-static and dynamic responses of the nested systems were comparable under an experimental
velocity of v¼4.5 m/sec. This is due to insignificant strain rate and inertia effects of the nested systems under the applied velocity. The performance indicators, which describe the effectiveness of energy absorbing systems, were calculated to compare the various nested systems and the best system was identified.
Furthermore, the effects of geometrical and loading parameters on the responses of the best nested tube system were explored via performing parametric analysis.
The parametric study was performed using validated finite element models. The outcome of this parametric study was full detailed design guidelines for such nested tube energy absorbing structures.