Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)
- Volume 1 Issue 1
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- Pages.131-139
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- 1993
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- 1225-6382(pISSN)
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- 2234-0149(eISSN)
Low Cycle Fatigue Characteristics of A356 Cast Aluminum Alloy and Fatigue Life Models
주조 알루미늄합금 A356의 저주기 피로특성 및 피로수명 모델
Abstract
Low cycle fatigue characteristics of cast aluminum alloy A356 with a yield strength and ultimate strength of 229 and 283 MPa respectively was evaluated using smooth axial specimen under strain controlled condition. Reversals to failure ranged from 16 to 107. The cast aluminum alloy exhibited cyclically strain-gardening behavior. The results of low cycle fatigue tests indicated that the conventional low cycle fatigue tests indicated that the conventional low cycle fatigue life model was not a satisfactory representation of the data. This occurred because the elastic strain-life curve was not-log-log linear and this phenomena caused a nonconservative and unsafe fatigue life prediction at both extremes of long and short lives. A linear log-log total strain-life model and a bilinear log-log elastic strain-life model were proposed in order to improve the representation of data compared to the conventional low cycle fatigue life model. Both proposed fatigue life models were statistically analyzed using F tests and successfully satisfied. However, the low cycle fatigue life model generated by the bilinear log-log elastic strain-life equation yielded a discontinuous curve with nonconservatism in the region of discontinuity. Among the models examined, the linear log-log total strain-life model provided the best representation of the low cycle fatigue data. Low cycle fatigue life prediction method based on the local strain approach could conveniently incorporated both proposed fatigue life models.
Keywords
- Low Cycle Fatigue;
- Local Strain Approach;
- Cyclic Stress-St-rain Behavior;
- Fatigue Strain-Life Model;
- F distribution;
- Bilinearity
- 저주기 피로;
- 국부변형률법;
- 주기 응력-변형률 거동;
- 피로 변형률 -수명모델;
- F 분포;
- 이선형성;