Interaction of Mechanical Heterogeneity and Residual Stress on Mechanical Field at Crack Tips in DMWJs

• Published in: Science and technology of nuclear installations 2022-02, Vol.2022, p.1-11
• Main Authors: Zhang, Yubiao, Xue, He, Zhang, Shun, Wang, Shuai, Sun, Yuman, Zhang, Yonggang, Yang, Yongjie
• Format: Article
• Language: English
• Subjects: Crack propagation; Crack tips; Dissimilar material joining; Dissimilar metals; Elastoplasticity; Experiments; Finite element analysis; Finite element method; Heterogeneity; Mechanical properties; Nuclear power plants; Residual stress; Strain distribution; Strain hardening; Stress corrosion cracking; Stress distribution; Stress propagation; Welded joints; Yield stress
• ISSN: 1687-6075; 1687-6083
• DOI: 10.1155/2022/7462200

The interaction between the mechanical heterogeneity and the residual stress in dissimilar metal welded joints (DMWJs) leads to a complex mechanical field of crack tips, which strongly affects stress corrosion cracking (SCC) behaviors. A dual-field coupling model was established by using the user-defined field (USDFLD) and the predefined stress field method based on the elastoplastic finite element method in this study. Thus, the mechanical heterogeneity and the residual stress of the DMWJ are realized. The influence of the interaction between the mechanical heterogeneity and the residual stress on the mechanical field of crack tips at different locations was investigated. The results show that the mechanical heterogeneity causes the stress and strain distribution on both sides of the crack tip asymmetry. And the residual stress affects the magnitude of the stress and strain around the crack tip. The variation trend of the stress and strain along the crack propagation with crack length is basically the same as that of the residual stress. However, the stress and strain distributions are slightly lagging behind the residual stress distribution due to the redistribution of the residual stress caused by the crack propagation. In addition, the stress and strain range of cracks at different positions with crack length are also different.