Evaluation of critical distance, highly stressed volume, and weakest-link methods in notch fatigue analysis

Abstract

Notch features normally lead to stress concentrations and thus present a non-legible influence on fatigue performance of critical engineering components. In this work, the predictive abilities of classic methods/theories for fatigue strength/life estimations under notch and size effects are explored and evaluated. Specifically, frameworks for fatigue strength/life estimation using the theory of critical distance (TCD), highly stressed volume (HSV) approach and weakest-link theory (WLT) are summarized, respectively, aiming to provide references for further engineering applications. Then, fatigue tests on the notched specimens of GH4169 alloy are conducted for model comparison and evaluation as well as experimental data of four other materials with different notch geometries. Results indicate that the TCD and WLT provide conservative fatigue life predictions, while the HSV approach yields better estimations on notch and size effects than the other two methods.