Akademik Veri Yönetim Sistemi
PHILOSOPHICAL MAGAZINE, 2025 (SCI-Expanded, Scopus)
The mechanical integrity of structural materials under cyclic loading conditions is vital for various industries. 304L stainless steel parts often undergo cyclic loading and stress hold periods resulting in time-dependent strain accumulation. In this work, effects of mean stress and stress hold periods on strain ratcheting are examined using crystal plasticity modelling. A representative volume element (RVE) consisting of 200 grains is subjected to various loadings in the DAMASK framework, employing an isotropic-kinematic hardening model. Simulations are performed under three types of stress-controlled loading conditions: low-cycle fatigue (LCF), creep-fatigue interaction (CFI) with cyclic stress holds, and fatigue after long hold (FLH). Cyclic loadings ranged from symmetric to non-symmetric loading with high mean stress. The model is validated through comparison with experimental ratcheting data. For LCF loading, high mean stresses lead to pronounced ratcheting, while symmetric loading results in significant hardening in the early stages of cyclic loading. Cyclic hold periods in CFI loading amplify strain accumulation by enabling sustained slip activity during hold phases. Long hold periods of FLH loading induce significant strain accumulation which continues to increase with extended hold duration but saturates during following cyclic loading. Quantitative and qualitative comparisons with relevant experimental data demonstrate that the simulations effectively capture ratcheting trends under various loading conditions.