Effectiveness and necessity of physics-based crystalline plasticity finite element method in analyzing fatigue crack behavior with strain localization

• Published in: Materials today communications Vol. 45; p. 112404
• Main Authors: Li, Wanjia, Kina, Taisei, Hamada, Shigeru
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2025
• Subjects: Crystal plasticity; Fatigue crack propagation; Finite element method; Strain localization; Finite element method; Crystal plasticity; Strain localization; Fatigue crack propagation
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2025.112404

Strain localization (SL) in metals manifests in various forms, including dislocation slip bands, Portevin-Le Chatelier (PLC) bands, dislocation pile-ups at grain boundaries, and shear bands. These phenomena contribute to strain hardening and softening, significantly influencing crack behavior. Although a physics-based crystal plasticity finite element method (CPFEM) model incorporating SL can simulate these localized deformation mechanisms, its suitability and accuracy in predicting stress and strain distribution around the crack tip remain uncertain. Furthermore, the necessity of employing CPFEM over the conventional elastic-plastic finite element method (EPFEM) for fatigue crack behavior prediction remains a subject of investigation. To address this, we analyzed the plastic strain distribution around the notch tip using a physics-based CPFEM model incorporating SL, complemented by an in situ tensile test on a notched specimen. The role of CPFEM in fatigue crack behavior prediction is evaluated by comparing its strain distribution results with those obtained from EPFEM around the notch tip. The findings indicate that the physics-based CPFEM model incorporating SL reliably predicts plastic strain distribution around the notch tip. Moreover, the model successfully captures SL phenomena arising from dislocation slip, PLC effects, shear band formation, and grain boundary interactions. Additionally, CPFEM is essential for accurately predicting damage accumulation fatigue crack propagation (DA-FCP). [Display omitted] •Physics-based crystalline plasticity finite element method with strain localization.•Strain distribution around notch tip investigated by numeral and DIC.•Strain localization from microstructure mechanisms in metal around notch tip.•Zooming analysis integrated EBSD and crystalline plasticity finite element method.•The necessity of crystalline plasticity finite element method on fatigue crack behavior.