PSI - Issue 28

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2020) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2020) 000 – 000 Available online at www.sciencedirect.com Procedia Structural Integrity 28 (2020) 200–207

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Abstract Due to the complex multiaxial loading service conditions for welded structures, it is a fundamental step to accurately compute the fatigue damage under complex stress states. Multiaxial low cycle fatigue behaviors of notch specimens considering geometry variations and strength heterogeneity for 10CrNi3MoV high strength steel and weldments under proportional and non-proportional loading modes were investigated in our study. The experimental results show that the crack initiates from the notch tip. The characteristic states of normal stress, shear stress and energy are analyzed to express the notch gradient behaviors. Furthermore, a new simplified fatigue damage parameter is proposed to predict the multiaxial low cycle fatigue life of notch components. This damage parameter is combined with Smith-Watson-Topper (SWT) damage parameter and notch stress concentration factor in the proximity of the notch tip. Finally, the proposed model gives more satisfactory estimations than other notch energy damage models for low cycle multiaxial fatigue life. Abstract Due to the complex multiaxial loading service conditions for welded structures, it is a fundamental step to accurately compute the fatigue damage under complex stress states. Multiaxial low cycle fatigue behaviors of notch specimens considering geometry variations and strength heterogeneity for 10CrNi3MoV high strength steel and weldments under proportional and non-proportional loading modes w re invest gated i our study. The experimental re ults show that the crack initiates from the notch tip. T characteristic states of n r al stress, he r tress and energy are analyzed to xpress the notch gradient behaviors. Furthermor , a new s mplified fati ue dama parameter is proposed to predict the mu tiaxial low cycle fatigue life of otch components. This damage parameter is combined with Smith-Watson-Top (SWT) damage parameter and notch stress concentratio factor in t proximity of the notch tip. Finally, the proposed model gives more s tisfactory estima ions than other otch energy damage dels for low cycle mul axial fatigu life. Keywords: Multiaxial fatigue; Low cycle fatigue; Notch sp cimen ; Und rmatched welds 1. Introduction Multiaxial fatigue behavior of metallic materials is a challenging topic, which is still open and worth of investigation, especially for the low cycle multiaxial fatigue failure of notch specimens. Due to the existence of geometrical discontinuities in fatigue engineering components and structures, such as notches or cracks, it will severely 1st Virtual European Conference on Fracture Multiaxial low cycle fatigue assessment of notch specimens for 10CrNi3MoV steel and its welds Wei Song a,b, *, Xuesong Liu b , Jie Xu c , Yu Fan c , Filippo Berto d a S chool of Mechanical & Electrical Engineering, Xuzhou University of Technology, Xuzhou 221018, PR China; b State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology(HIT), Harbin 150001, PR China; c School of Materials Science and Engineering, China University of Mining and Technology (CUMT), 221116 Xuzhou, PR China; c Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway. 1st Virtual European Conference on Fracture Multiaxial low cycle fatigue assessment of notch specimens for 10CrNi3MoV steel and its welds Wei Song a,b, *, Xuesong Liu b , Jie Xu c , Yu Fan c , Filippo Berto d a S chool of Mechanical & Electrical Engineering, Xuzhou University of Technology, Xuzhou 221018, PR China; b State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Te hnology(HIT), Harbin 150001, PR China; c School of Materials Science and Engineering, China University of Mining and Technology (CUMT), 221116 Xuzhou, PR China; c Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway. Keywords: Multiaxial fatigue; Low cycle fatigue; Notch specimens; Undermatched welds 1. Introduction Multiaxial fatigue behavior of metallic materials is a challenging topic, which is still open and worth of investigation, especially for the low cycle multiaxial fatigue failure of notch specimens. Due to the existence of geometrical discontinuities in fatigue engineering components and structures, such as notches or cracks, it will severely

* Corresponding author. Tel.: +86-15204506099. E-mail address: swingways@hotmail.com.

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.10.025 2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open acce s article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo * Corresponding author. Tel.: +86-15204506099. E-mail address: swingways@hotmail.com.