Citation

Caine YG, Bain-Ungerson O, Schochat I, Marom G. Aviat. Space Environ. Med. 1991; 62(6): 587-592.

Affiliation

Israel Air Force Aeromedical Center, Tel Hashomer.

Copyright

(Copyright © 1991, Aerospace Medical Association)

DOI

unavailable

PMID

1859350

Abstract

Understanding why a flying helmet fails to maintain its integrity during an accident can contribute to an understanding of the mechanism of injury and even of the accident itself. We performed a post-accident evaluation of failure modes in glass and aramid fibre-reinforced composite helmets. Optical and microscopic (SEM) techniques were employed to identify specific fracture mechanisms. They were correlated with the failure mode. Stress and energy levels were estimated from the damage extent. Damage could be resolved into distinct impact, flexure and compression components. Delamination was identified as a specific mode, dependent upon the matrix material and bonding between the layers. From the energy dissipated in specific fracture mechanisms we calculated the minimum total energy imparted to the helmet-head combination and the major injury vector (MIV) direction and magnitude. The level of protection provided by the helmet can also be estimated.

Language: en