Citation

Demarco AL, Chimich DD, Gardiner JC, Nightingale RW, Siegmund GP. Accid. Anal. Prev. 2010; 42(6): 1778-1784.

Affiliation

MEA Forensic Engineers & Scientists, 11-11151 Horseshoe Way, Richmond, BC, Canada V7A 4S5.

Copyright

(Copyright © 2010, Elsevier Publishing)

DOI

10.1016/j.aap.2010.04.019

PMID

20728629

Abstract

Helmets reduce the frequency and severity of head and brain injuries over a range of impact severities broader than those covered by the impact attenuation standards. Our goal was to document the impact attenuation performance of common helmet types over a wide range of impact speeds. Sixty-five drop tests were performed against the side of 10 different helmets onto a flat anvil at impact speeds of 0.9-10.1m/s (energy=2-260J; equivalent drop heights of 0.04-5.2m). Three non-approved beanie helmets performed poorly, with the worst helmet reaching a peak headform acceleration of 852g at 29J. Three full-face and one open-face helmet responded similarly from about 100g at 30J to between 292g and 344g at 256-260J. Three shorty style helmets responded like the full-face helmets up to 150J, above which varying degrees of foam densification appeared to occur. Impact restitution values varied from 0.19 to 0.46. A three-parameter model successfully captured the plateau and densification responses exhibited by the various helmets (R(2)=0.95-0.99). Helmet responses varied with foam thickness, foam material and possibly shell material, with the largest response differences consistent with either the presence/absence of a foam liner or the densification of the foam liner.

Language: en