Energy-Absorbing Earcup Engineering Feasibility Evaluation,

Abstract

The concept of using the integral structure of a noise-attenuating earcup as a 'load-limiting' or energy-absorbing device is explored in this report. The standard earcup of the Army's SPH-4 flight helmet is a very rigid structure which requires a force of approximately 22,000 newtons to cause it to deform, a force level three times greater than the crushing strength of the skull. Fifteen different 'crushable' earcups were constructed and evaluated for noise attenuation to determine their suitability for prototype construction. Three earcups were selected for the 'crushability' evaluation. The corrugated aluminum earcup was selected as the best of the three evaluated. The aluminum earcup was modified to lower the cost and to increase the crushing depth to nearly 2 cm. The feasibility of producing a 'crushable' earcup with similar noise attenuation characteristics to the existing Army SPH-4 earcup was demonstrated.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1984
Accession Number
ADA144179

Entities

People

  • J. L. Haley Jr.
  • T. A. Hundley

Organizations

  • United States Army Aeromedical Research Lab

Tags

Communities of Interest

  • Biomedical
  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Attenuation
  • Air Force
  • Aluminum
  • Attenuation
  • Aviation Accidents
  • Dynamic Tests
  • Engineering
  • Flight Helmets
  • Health Services
  • Helmets
  • Human Factors Engineering
  • Materials
  • Military Research
  • Security
  • Skull
  • Standards
  • Test And Evaluation

Readers

  • Acoustics.
  • Mechanical Engineering/Mechanics of Materials.
  • Pavement Materials Engineering.