THE DYNAMIC BEHAVIOR OF CRASH HELMETS

This paper summarizes work carried out at R. A. E. on the protection of the head in crashes. In general, two problems are seen to exist; the prevention of skull fracture and the prevention of concussion. The skull can be protected within quite wide limits by spreading the load, but little can be done directly by helmets of practicable size to prevent concussion. The likelihood of brain injury can be reduced slightly by designing helmets with low elasticity and a tendency to deflect blows. Kinetic energy and the peak force transmitted to the head are often regarded as the sole criteria needed to define a blow, but it is shown that the coefficient of restitution and stopping distance are also important parameters. Account should be taken of the effect of the ratio of the colliding masses and the effect of varying momentum when comparing test results from various rigs. A simple calibration device using a shaped plasticine test-piece is put forward to compare the behavior of different test machines under given conditions. The effect of varying different parameters is illustrated by experiments on two test rigs and tests on existing service helmets are reported. (A)

• Corporate Authors:

  Royal Aircraft Establishment

  Engineering Physics Department
  Farnborough, Hampshire,   England 
• Authors:
  • Rayne, J M
• Publication Date: 1972

Media Info

• Features: Figures; References;
• Pagination: 73 p.

Subject/Index Terms

• TRT Terms: Brain; Calibration; Dynamics; Experiments; Head; Helmets; Momentum; Shock (Pathology); Stopping distances
• Uncontrolled Terms: Dynamic characteristics; Parameters
• Old TRIS Terms: Concussion
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00132072
• Record Type: Publication
• Source Agency: National Safety Council Safety Research Info Serv
• Report/Paper Numbers: Rept No ARC-CP-1202, Rept No RAE-TR-69160
• Files: TRIS
• Created Date: Oct 29 1977 12:00AM