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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;Kong, Yu Sik
김선진;공유식

  • Received : 2016.03.16
  • Accepted : 2016.06.21
  • Published : 2016.08.01

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.

Keywords

Crank Throw;Reliability;Fatigue Limit;Design Fatigue Strength;Staircase Method;Fatigue Testing

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