Predicting motorcycle helmet impact severity from residual crush damage

DeMarco, A. L.; Gardiner, J. C.; Wilkinson, C. C.; Hassan, E. A; Siegmund, G. P.

Affiliations

¹MEA Forensic Engineers & Scientists, Richmond, BC, Canada

²School of Human Kinetics, University of British Columbia, Vancouver, BC, Canada

Abstract

Motorcycle helmets reduce the frequency and severity of head and brain injuries by attenuating head acceleration and distributing the impact force. This is achieved primarily through permanent crushing of the interior energy absorbing liner. Our goal is to characterize the relationship between residual helmet damage and impact energy. Working toward this goal, the current study measures the changes in energy absorbing liner residual thicknesses for helmets subjected to drop tests of various severities. We conducted 32 single drop tests of five different helmets on a flat anvil at impact energies of 30 to 259 J (impact speeds = 3.4 to 10 m/s). Percent maximum crush, percent crush volume and stiffness were determined for each helmet impact. For the full-face style helmets tested, linear correlations (r² gt; 0.9) were found showing an increase in the change in thickness measures with increasing impact severities. The shorty helmet showed this trend as well, but also showed a steep increase in percent maximum crush above about 180 J. Of the helmets tested over the range of severities, the stiffness values were found highest at the lowest severity impacts (30 J).

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/bio/proceedings/2007_35/35-5.pdf

Cited Works (8)

Year	Entry
1993	Beusenberg MC, Happee R. An experimental evaluation of crash helmet design and effectiveness in standard impact tests. In: Proceedings of the 1993 International IRCOBI Conference on the Biomechanics of Impact. September 8-10, 1993; Eindhoven, The Netherlands.307-323.
1990	Hopes PD, Chinn BP. The correlation of damage to crash helmets with injury, and the implications for injury tolerance criteria. In: Proceedings of the 1990 International IRCOBI Conference on the Biomechanics of Impact. September 12-14, 1990; Lyon, France.319-331.
2003	Wobrock J, Smith T, Kasantikul V, Whiting W. Effectiveness of collision-involved motorcycle helmets in Thailand. In: 47th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). September 22-24, 2003; Lisbon, Portugal.1-23.
1993	Schuller E, König W, Beier G. Criteria for head impact protection by motorcycle helmets. In: Proceedings of the 1993 International IRCOBI Conference on the Biomechanics of Impact. September 8-10, 1993; Eindhoven, The Netherlands.283-294.
1993	Zellmer H. Investigation of the performance of motorcycle helmets under impact conditions. In: Proceedings of the 37th Stapp Car Crash Conference. November 7-8, 1993; San Antonio, TX. Warrendale, PA: Society of Automotive Engineers:59-68. SAE 933113.
1994	Mitsuishi H, Ono K, Nishimoto T, Nakamura N. Present and future performance levels of head injury protection for motorcycle helmets: an attempt to search for better impact energy absorption property of helmets. In: Proceedings of the 1994 International IRCOBI Conference on the Biomechanics of Impact. September 21-23, 1994; Lyon, France.259-270.
2005	Mellor A, StClair V. Advanced motorcycle helmets. In: Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 6-9, 2005; Washington, DC.
2006	DeMarco AL, Chimich DD, Gardiner JC, Nightingale RW, Siegmund GP. Motorcycle helmet impact response: comparison of helmet type and impact severity. In: Proceedings of the 34th International Workshop on Human Subjects for Biomechanical Research. 2006.15-24.

Cited By (1)

Year	Entry
2012	DeMarco AL, Siegmund GP. Motorcycle helmet impact behavior depends on impact surface shape. In: Proceedings of the 40th International Workshop on Human Subjects for Biomechanical Research. 2012.