Influence of the body on head rotational acceleration in motorcycle helmet oblique impact tests

Ghajari, Mazdak; Peldschus, Steffen; Galvanetto, Ugo; Asgharpourb, Zahra; Iannucci, Lorenzo

Affiliations

¹Imperial College London, Department of Aeronautics, London, UK

²Ludwig-Maximilians University, Institute of Legal Medicine, Munich, Germany

³Padova University, DCT, Padova, Italy

Abstract and keywords

The Finite Element (FE) method has been used to study full-scale oblique impacts of a motorcycle helmet. For these impacts, an elaborate FE model of the human body was employed. The results were compared to the results of the same impacts but by using the detached head of the body. It has been found that the presence of the body influences the head rotational acceleration components (up to 40% for the simulated impact configuration). On the basis of the equations of general three-dimensional motion of a rigid body, it is shown that this influence can be taken into account in detached head impact tests through modifying the inertia matrix of the head. For a severe oblique impact, the modified inertia was calculated and applied to the head. The head rotational acceleration components predicted by using the modified detached head were in good agreement with those obtained from fullscale oblique impacts.

Keywords: Helmets; Human Body; Full Scale Tests; Drop Tests; Finite Element Method

Cited Works (8)

Year	Entry
2006	Kitagawa Y, Yasuki T, Hasegawa J. A study of cervical spine kinematics and joint capsule strain in rear impacts using a human FE model. Stapp Car Crash J. 2006;50:545-566. SAE 2006-22-0020.
1983	Gennarelli TA. Head injury in man and experimental animals: clinical aspects. Acta Neuropathol Suppl. 1983;32:1-13.
2009	Ghajari M, Galvanetto U, Iannucci L. Influence of the body on kinematic and tissue level head injury predictors in motorcyclists accidents. In: Proceedings of the 2009 International IRCOBI Conference on the Biomechanics of Impact. September 9-11, 2009; York, UK.275-286.
1943	Holbourn AHS. Mechanics of head injuries. Lancet. October 9, 1943;242(6267):438-441.
1996	Nightingale RW, McElhaney JH, Richardson WJ, Myers BS. Dynamic responses of the head and cervical spine to axial impact loading. J Biomech. March 1996;29(3):307-318.
1998	Herbst B, Forrest S, Chng D, Sances A Jr. Fidelity of anthropometric test dummy necks in rollover accidents. In: Proceedings of the 16th International Technical Conference on the Enhanced Safety of Vehicles (ESV). May 31–June 4, 1998; Windsor, Ontario, Canada.2093-2097.
2004	Chawla A, Mukherjee S, Mohan D, Parihar A. Validation of lower extremity model in THUMS. In: Proceedings of the 2004 International IRCOBI Conference on the Biomechanics of Impact. September 22-24, 2004; Graz, Austria.155-166.
1992	Margulies SS, Thibault LE. A proposed tolerance criterion for diffuse axonal injury in man. J Biomech. August 1992;25(8):917-923.

Cited By (1)

Year	Entry
2011	Ghajari M, Galvanetto U, Iannucci L, Willinger R. Intracranial response in helmet oblique impacts. In: Proceedings of the 2011 International IRCOBI Conference on the Biomechanics of Injury. September 14-16, 2011; Krakow, Poland.90-94.