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| Stochastic model of strength degradation based on P-S-N curve |
| Received:December 18, 2013 Revised:February 08, 2014 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7511/jslx201501020 |
| KeyWord:strength degradation Gamma process P-S-N curve parameter estimation |
| Author | Institution |
| 安宗文 |
兰州理工大学 机电工程学院, 兰州 |
| 高建雄 |
兰州理工大学 机电工程学院, 兰州 |
| 刘波 |
兰州理工大学 机电工程学院, 兰州 |
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| Abstract: |
| In general,strength degradation is a stochastic and irreversible process.Gamma process is an independent nonnegative increment process which can be used to describe the characteristics of strength degradation.However,during strength degradation process,the degradation data that characterizes degenerate state (wear,crack,corrosion,etc.) is often difficult to measure directly,which is the typical missing data.But the P-S-N curve that characterizes material fatigue performance is generally easy to obtain.Therefore,this paper assumes that the shape parameter of Gamma process is a linear function,and estimates the characteristic parameters of Gamma process using material P-S-N curve.Then a stochastic model of strength degradation based on P-S-N curve is established.Finally,the validity of the proposed model is verified and analyzed by using the fatigue test data of 20CrMnTi steel.The results show that this model can effectively describe the macroscopic trend of material strength degradation. |
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