Impact and energy absorption of empty and foam-filled conical tubes

Ahmad, Zaini (2009) Impact and energy absorption of empty and foam-filled conical tubes. PhD thesis, Queensland University of Technology.


Foam-filled conical tubes have recently emerged as efficient energy absorbing devices to mitigate the adverse effects of impacts. The primary aim of this thesis was to generate research and design information on the impact and energy absorption response of empty and foam-filled conical tubes, and to facilitate their application in energy absorbing systems under axial and oblique loading conditions representative of those typically encountered in crashworthiness and impact applications. Finite element techniques supported by experiments and existing results were used in the investigation. Major findings show that the energy absorption response can be effectively controlled by varying geometry and material parameters. A useful empirical formula was developed for providing engineering designers with an initial estimate of the load ratio and hence energy absorption performances of these devices. It was evident that foam-filled conical tubes enhance the energy absorption capacity and stabilise the crush response for both axial and oblique impact loading without a significant increase in the initial peak load. This is practically beneficial when higher kinetic energy needs to be absorbed, thus reducing the impact force transmitted to the protected structure and occupants. Such tubes also increase and maintain the energy absorption capacity under global bending as well as minimise the reduction of energy absorption capacity with increasing load angle. Furthermore, the results also highlight the feasibility of adding a foam-filled conical tube as a supplementary device in energy absorbing systems, since the overall energy absorption performance of such systems can be favourably enhanced by only including a relatively small energy absorbing device. Above all, the results demonstrate the superior performance of foam-filled conical tube for mitigating impact energy in impact and crashworthiness applications.

Impact and interest:

63 citations in Web of Science®
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ID Code: 31908
Item Type: QUT Thesis (PhD)
Supervisor: Thambiratnam, David & Tan, Chit
Keywords: foam, conical tubes, energy absorption, axial loading, oblique impact, finite element analysis, computer simulation, crashworthiness
Divisions: Past > QUT Faculties & Divisions > Faculty of Built Environment and Engineering
Past > Schools > School of Urban Development
Institution: Queensland University of Technology
Deposited On: 21 Apr 2010 04:30
Last Modified: 28 Oct 2011 19:56

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