Fatigue life prediction of notched components under size effect using critical distance theory

Notch and size effects have shown significant influences on fatigue performance of engineering components, which deserve special attentions when performing structural health assessment. Thus, a possible size effect on critical distance is identified, when evaluating fatigue lives of notched specimens using the theory of critical distance.. In this work, by introducing the relative stress gradient concept, a novel reformulation of critical distance theory is proposed to consider the size effect in notch fatigue analysis. Experimental data of GH4169 Ni-based alloy, Al 2024-T351 alloy, and En3B low carbon steel notched specimens are applied for model validation and comparison. Results indicate that all predicted lives based on the proposed method agree well with the experimental values.

Automated summary

Notch and size effects have significant influences on fatigue performance of engineering components. A novel reformulation of critical distance theory is proposed in this study to consider the size effect in notch fatigue analysis by introducing the relative stress gradient concept.