Probabilistic modelling of notch and size effect of components under fatigue loadings

Abstract For ensuring structural integrity and reliability of engineering components, it is vital to accurately model notch and size effects on fatigue behavior of materials. Based on the highly stressed volume approach, this paper proposes a methodology considering both effects of notch and size to predict the fatigue life distribution of specimens with different geometries. In detail, under Weibull distribution, a dynamic model coefficient vary with different maximum local stresses is proposed by quantifying the highly stressed volumes of different sizes. Experimental data of two alloys are applied for model validation and comparison. Fatigue life distributions of two materials with different geometries are predicted respectively, and estimated P-S-N curves indicate that proposed model predictions agree well with the probabilistic scatter band of experimental results.