Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Prediction of Reliability of Fatigue Limit of S34MnV Steel for Marine Diesel Engine Crank Throw Components

선박용 디젤 엔진 크랭크 스로 부품용 S34MnV강의 피로한도에 대한 신뢰도 예측

  • Kim, Seon Jin (Dept. of Mechanical Design Engineering, Pukyong Nat'l Univ.) ;
  • Kong, Yu Sik (Dept. of Mechanical Engineering, Pukyong Nat'l Univ.)
  • 김선진 (부경대학교 기계설계공학과) ;
  • 공유식 (부경대학교 기계공학과)
  • Received : 2016.03.16
  • Accepted : 2016.06.21
  • Published : 2016.08.01
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Abstract

The aim of this study is to estimate the reliability of fatigue limit of the material used for crank throw components according to the staircase method. The material used for crank throw components is forged S34MnV grade steel, which is heat treated by normalizing and tempering. In this work, to predict the reliability of the design fatigue strength, axially loaded constant amplitude fatigue testing was conducted. The test specimens were loaded with an axial push/pull load with a mean stress of 0 MPa, which corresponds to a stress ratio of R=-1. The fatigue test results were evaluated by Dixon-Mood formulas. The values of mean fatigue strength and standard deviation predicted by the staircase method were 296.3 MPa and 10.6 MPa, respectively. Finally, the reliability of the fatigue limit in some selected probability of failure is predicted. The proposed method can be applied for the determination of fatigue strength for design optimization of the forged steel.

본 논문은 스테어케이스법을 사용하여 크랭크 스로 부품용 S34MnV강의 피로한도의 신뢰도를 평가하는 것이다. 크랭크 스로 부품의 소재는 S34MnV이며, 뜨임 및 풀림 열처리된 단조강이다. 본 연구에서는 설계피로강도의 신뢰도를 예측하기 위해 축 하중 일정진폭 피로시험을 수행하였다. 시험편은 평균응력 0 MPa의 동일한 응력부하를 적용하였고, 즉 응력비는 -1로 하였다. 피로시험 결과는 Dixon-Mood 접근법으로 평가하였다. 스테어케이스법에 의해 예측된 피로강도의 평균과 표준편차는 각각 296.3 MPa 및 10.6 MPa로 나타났다. 마지막으로 어떤 임의의 파손 확률에 대한 피로강도의 신뢰도를 예측하였다. 본 연구에서 제안한 예측법은 단조강의 설계 최적화를 위한 피로강도 값을 결정할 수 있다.

Keywords

References

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