A strain-based fatigue crack growth model for 316 austenitic stainless steel under fully reversed loadings

In this paper, a strain-intensity-factor-based method is proposed to calculate the fatigue crack growth of 316 austenitic stainless steel under the fully reversed loading condition. The theoretical and experimental investigations are performed to demonstrate that the strain intensity factor is likely to be a better driving parameter to correlate with the fatigue crack growth rate than the stress intensity factor (SIF), especially for some stainless steels with the negative stress ratio. A probable explanation is that the relationship between the cyclic stress and strain is not linear in these cases. And then, a comparison between the stress-based and strain-based fatigue life methods is conducted to validate our proposed model. The results show that our proposed method has a very good agreement with the testing data.