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A Study on the Shock Absorption Performance of the Safety Helmet using Coefficient of Restitution

반발계수를 이용한 안전모의 충격 흡수 성능에 관한 연구

  • Received : 2012.07.08
  • Accepted : 2012.09.26
  • Published : 2012.10.31

Abstract

A safety helmet is a personal protective equipment to protect the head from falling and flying objects. A safety helmet has the maximum delivered impact force as shock absorption performance, the lower delivered impact force the better performance, which was not a controlled variety during manufacturing safety helmet. Accordingly there were some difficulties in establishing the standard for improved performance as there was not a clear controllable impact force for improved performance. In this study the shock absorption performance was intended to be found as coefficient of restitution related to impulse. As a research method, a coefficient of restitution during the absorption of shock was calculated using the impulse transferred to pharynx utilizing the safety helmet shock absorption performance testing device based on the theory of momentum and impulse. The estimated impulsive force curve was derived assuming that shock was not absorbed using the measured data. The sample was selected as tested goods of ABS material for safety certification available mainly in the market. As a result of study, the maximum delivered impact force of safety helmet made by a domestic safety certified a company was 735 N, and its coefficient of restitution proved to be 0.64. The smaller coefficient of restitution is, the lower maximum delivered impact force and the higher shock absorption performance. The coefficient of restitution can be used as a performance index of safety helmet.

Keywords

coefficient of restitution;delivered impact force;safety helmet;shock absorption performance

References

  1. 김한구, 심종현, 김청균, "소방 가스 안전용 헬멧의 강도 안전성에 관한 연구", 한국가스학회지, Vol. 12, No. 3, pp. 33-37, 2008.
  2. 한응교 외 3명, "소방 안전모의 안전도 평가에 관한 연구", 한국화재소방학회지, Vol. 5, No. 3, pp. 5-14, 1991.
  3. 김연우, 박경수, "안전모의 충격전달에 관한 이론적 고찰", 대한인간공학회지, Vol. 9, No. 1, pp. 29-33, 1990.
  4. Anthony S.Hu, "Head Impact Rotainal Measurements and Frequency Response", J. Biomechanics, Vol. 13, pp. 615-622, 1984.
  5. 김청균, 김도현, "헬멧의 강도안전과 변형 거동에 관한 수치적 연구", KIGAS, Vol. 12, No. 4, pp. 41-42, 2008.
  6. 이윤기, 성원석, 임동진, 선신규, "폴리프로필렌 폼밀도가 충격에너지 흡수에 미치는 영향에 대한 실험적 연구", 한국안전학회지, Vol. 23, No. 6, pp. 25-27, 2008
  7. Gaetano, D. Caserta, Lorenzo Iannucci, Ugo Galvanetto, "Shock Absorption Performance of a Motorbike Helmet with Honeycomb Reinforced Liner", Elsevier, Composite Structures 93, pp. 2754-2758, 2011.
  8. 윤대병 외 4명, 대학물리학, pp. 95-101, 1990.
  9. 보호구 의무안전인증고시(노동부 고시 제 2009-38호 : 2009. 9. 25), 제 2장 제4조
  10. 최용근, "산업용 안전모의 충격흡수 이론", 한국산업안전학회지, Vol. 6, No. 2, pp. 37-40, 1991.