Coupled Micromechanics–Continuum Damage Mechanics Framework for Probabilistic Prediction of Torsional Fatigue in AISI 52100 Steel

Document Type : Research Article

Authors

Academic Complex of Materials and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran, Iran

10.22060/mej.2026.25075.7920

Abstract

In this study, the effects of grain size distribution and material property variations (Young’s modulus) on the probabilistic-based torsional fatigue life prediction of the AISI 52100 alloy were investigated. To this end, continuum damage mechanics and micromechanics based on Voronoi tessellation were coupled. Six stress levels with fifteen analyses per level were performed using a two-dimensional finite element model. Employing the Monte Carlo method with a 95% confidence level, ten thousand data samples were generated for each stress level. The dispersion in fatigue life was evaluated considering random variations in grain geometry and material properties (Young’s modulus). It was assumed that damage initiation and propagation occur along grain boundaries. The damage growth rate (DΔ) was determined for the case where Young’s modulus variation was zero. The results of the two-dimensional finite element model and single-element finite element analysis were compared with the available experimental data for this alloy. Due to the high scatter in fatigue life, curve fitting was employed to compare analytical and experimental results. The fitting results showed that the error between the present study and the experimental data does not exceed 6%.

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