Motorcycle helmet test headform and test apparatus comparison

Thom, David R.; Hurt, Jr, Hugh H.; Smith, Terry A.

Affiliations

¹Head Protection Research Laboratory, United States

Abstract

Internationally, there are two types of headforms used for impact attenuation testing of motorcycle helmets. These two types of test headforms follow specifications established by the International Standards Organization (ISO), or the U.S. Department of Transportation (DOT). Both headforms are low resonance, rigid castings, but they differ in size, shape and weight. The headforms are supported by a rigid guide assembly that limits their motion to the vertical direction only. Different impact locations are obtained by adjustment of the headform on a spherical ball joint. Performance criteria are based on acceleration time history measurements from a uniaxial accelerometer located at the headform center of mass.

A second variation on the IS0 headform is found in some European helmet standards that utilize an unrestrained headform instrumented with a triaxial accelerometer. These constrained headforms respond to impact with motion in many directions and performance criteria are based on the resultant of three axis acceleration time histories.

Impact attenuation tests were performed on 180 motorcycle helmets of three different designs and under environmental conditions specified by helmet performance standards. Selected tests were recorded on high-speed (1000 Hz) videotape for motion analysis. Test apparatus designs differ greatly and guided free-fall apparatus with restrained headforms produces consistently more rigorous tests than apparatus without headform guide or restraint. Significant differences were also found between DOT and IS0 headforms for both peak acceleration and dwell time on flat anvil impacts when tested on the DOT-type monorail apparatus.

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv16/98s10p29.pdf

Cited Works (5)

Year	Entry
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Cited By (3)

Year	Entry
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.
2017	Bonin SJ. Dynamic Response and Residual Helmet Liner Crush Using Cadaver Heads and Standard Headforms [PhD thesis]. University of Miami; May 2017.
2011	Coulson NR. The Influence of Impact Mass, Inbound Velocity and System Compliance on the Dynamic Response of a Hybrid III Head Form [Master's thesis]. Ottawa, ON: University of Ottawa; 2011.