Issue 45

L. Zou et alii, Frattura ed Integrità Strutturale, 45 (2018) 53-66; DOI: 10.3221/IGF-ESIS.45.05 53 Fatigue life prediction of 5083 and 5A06 aluminum alloy T-welded joints based on the fatigue characteristics domain Li Zou, Xinhua Yang Dalian Key Laboratory of Welded Structures and Its Intelligent Manufacturing Technology (IMT) of Rail Transportation Equipment, Dalian Jiaotong University, China; Sichuan Provincial Key Lab of Process Equipment and Control, China Lizou@djtu.edu.cn, yangxhdl@foxmail.com Jianrong Tan Department of mechanical engineering and automation, Zhejiang University, China tjr@cad.zju.edu.cn Hongji Xu, Yibo Sun Dalian Key Laboratory of Welded Structures and Its Intelligent Manufacturing Technology (IMT) of Rail Transportation Equipment, Dalian Jiaotong University, China xuhongji@djtu.edu.cn , yibo_sun@126.com A BSTRACT . Three-point bending fatigue test of 5083 and 5A06 aluminum alloy T-welded joints is carried out, and the fatigue life of the specimens with different influencing factors are obtained. Finite element model of the T- welded joint is established and the nodal force based structural stress is calculated. Neighborhood rough set theory is used for analysis of the factors which influence the fatigue life of the aluminum alloy welded joints. Key influencing factors are studied and the fatigue characteristic domains are determined. The master S-N curve characterized by the nodal force based structural stress range and cycles to failure on bi-logarithmic coordinate as well as S-N curves corresponding to the fatigue characteristic domain are fitted. A case study of fatigue life prediction of 5A06 aluminum alloy welded joint indicates the effectiveness of the fatigue life prediction method based on the fatigue characteristic domain. K EYWORDS . Fatigue life; Welded joints; Fatigue characteristic domain. Citation: Zou, L., Yang, X., Tan, J., Xu, H., Sun, Y., Fatigue life prediction of 5083 and 5A06 aluminum alloy T-welded joints based on the fatigue characteristic domain, 45 (2018) 53-66. Received: 10.02.2018 Accepted: 06.04.2018 Published: 01.07.2018 Copyright: © 2018 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION aster S-N curve method, also called equivalent structural stress method or nodal force based structural stress method is a new type of fatigue life prediction technology for welded structures proposed by Dong etc. [1, 2] at the beginning of this century. The structural stress calculated in the master S-N curve method is mesh- M