Multiaxial thermo-mechanical fatigue life prediction based on notch local stress-strain estimation considering temperature change

• Published in: Engineering fracture mechanics 2022-04, Vol.265, p.108384, Article 108384
• Main Authors: Chen, Feng, Shang, De-Guang, Li, Dao-Hang, Wang, Ling-Wan
• Format: Article
• Language: English
• Subjects: Constitutive models; Effective stress concentration factor; Fatigue failure; Fatigue life; Finite element method; Life prediction; Local stress-strain estimation; Notch fatigue life prediction; Oxidation; Strain analysis; Stress-strain relationships; Temperature change; Thermal-structural nonlinear FEA
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/j.engfracmech.2022.108384

•A modified incremental multiaxial Neuber notch correction method considering temperature change was proposed.•The proposed approximate calculation method can accurately and quickly obtain the notch-root local stress-strain history.•A fast life prediction method is developed under variable amplitude multiaxial thermo-mechanical loading. The modified incremental multiaxial Neuber rule by considering the temperature change was firstly proposed, which combined with the Chaboche viscoplastic constitutive model to approximately compute the notch local stress and strain under multiaxial thermo-mechanical loading. Based on the proposed method, a life prediction method that can take into account fatigue, oxidation, and creep damage was developed, which can quickly predict notch fatigue failure lifetime under variable amplitude multiaxial thermo-mechanical loading. The proposed method was verified by the coupled thermal-structural nonlinear FEA and the experimental life results for the tenon joint structure specimens under eight thermo-mechanical loading paths. The comparison of computed and analyzed stress-strain history showed that a good agreement can be obtained. Comparing with experimental life data, all predicted lives fall in a 2-factor scatter band.