Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)

The Korean Society of Automotive Engineers (한국자동차공학회)
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Reliability Analysis and Feilure Mechanisms of Coolant Rubber Hose Materials for Automotive Radiator

자동차 냉각기 고무호스용 재질에 대한 신뢰성 평가 및 고장메커니즘규명

  • Kwak Seung-Bum (Department of Mechanical Design and Production Engineering, Hanyang University) ;
  • Choi Nak-Sam (Department of Mechanical Engineering, Hanyang University) ;
  • Kang Bong-Sung (Reliability Assessment Center, Korea Research Institute of Chemical Technology) ;
  • Shin Sei-Moon (Reliability Assessment Center, Korea Research Institute of Chemical Technology)
  • 곽승범 (한양대학교 기계설계학과) ;
  • 최낙삼 (한양대학교 기계정보경영공학부) ;
  • 강봉성 (한국화학연구원 신뢰성평가센터) ;
  • 신세문 (한국화학연구원 신뢰성평가센터)
  • Published : 2005.09.01
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Abstract

Coolant rubber hoses for automobile radiators can be degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under the thermal and mechanical loadings. In this study, test analysis was carried out for evaluating the degradation and failure mechanisms of coolant hose materials. Two kinds of EPDM rubber materials applicable to the hoses were adopted: commonly-used ethylene-propylene diene monomer(EPDM) rubbers and EPDM rubbers with high resistance against electro-chemical degradation (ECD). An increase of surface hardness and a large reduction of failure strain were shown due to the formation of oxidation layer for the specimens which had been kept in a high temperature air chamber. Coolant ageing effects took place only by an amount of pure thermal degradation. The specimens degraded by ECD test showed a swelling behavior and a considerable increase in weight on account of the penetration of coolant liquid into the skin and interior of the rubber specimens. The ECD induced material softening as well as drastic reduction in strength and failure strain. However EPDM rubbers designed for high resistance against ECD revealed a large improvement in reduction of failure strain and weight. This study finally established a procedure for reliability analysis and evaluation of the degradation and failure mechanisms of EPDM rubbers used in coolant hoses for automobile radiators.

Keywords

References

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