Expanded Polystyrene Re-Expansion Analysis Following Impact Compression

Abstract

Post-accident aviator helmet analysis involves a visual inspection of damage to the energy absorbing liner. U.S. Army aviator helmets use expanded bead polystyrene (EPS) of various densities for the energy attenuating liner (EAL) material. This material is known to rebound after compression, and the rebound properties must be understood in order to estimate the actual EAL compression sustained in an impact. This report describes the method and results of compression and rebound tests on the four polystyrene densities, illustrating the results in the form of regression curves. A high degree of linear correlation was found between initial compression and the final thickness ratio of the EPS material. Rebound was essentially complete 24 hours after compression. The results will be used also when examining post-accident helmet damage to help determine helmet impact forces experienced in survivable helicopter accidents.

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Document Details

Document Type
Technical Report
Publication Date
Mar 04, 2015
Accession Number
ADA616948

Entities

People

  • Frederick Brozoski
  • Katie Logsdon
  • Mark S. Adams

Organizations

  • United States Army Aeromedical Research Lab

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Accident Investigations
  • Accidents
  • Cells
  • Composite Materials
  • Dielectric Polymers
  • Failure Analysis
  • Head Injuries
  • Helmets
  • Impact Loads
  • Low Density
  • Materials
  • Materials Laboratories
  • Materials Processing
  • Measurement
  • Personal Protective Equipment
  • Polystyrenes
  • Protective Equipment

Readers

  • Explosive Engineering.
  • Materials Science
  • Military Engineering.