Issue 52

W. Xiangming et alii, Frattura ed Integrità Strutturale, 52 (2020) 25-32; DOI: 10.3221/IGF-ESIS.52.03 25 Numerical analysis and verification of residual stress in T joint of S355 steel Wang Xiangming, Guo Erfu School of Mechanical and Electrical Engineering, Shijiazhuang University of Applied Technology, Shijiazhuang, 050081 wangxmxming@163.com A BSTRACT . T joint is a widely used welding form. The welding deformation and residual stress produced during the welding process affect the integrity and reliability of the resultant structure. In this study, S355 low alloy steel was used as test material, and the thermal-mechanical coupling characteristics of multi-layer welding were combined with SYSWELD finite element software to calculate the residual welding stress of T joint. The residual welding stress of multi-layer welding T joint with tangent tube and sheet was measured using X-ray diffraction method. The results showed that the numerical simulation was in good agreement with the experimental findings. With respect to the transverse residual stress, the maximum residual stress appeared near the weld toe. The transverse stress perpendicular to the weld direction represented the tensile stress at the weld center as well as the tensile stress at the tube surface far from the weld. Regarding longitudinal residual stress, the maximum residual stress also appeared near the weld toe, and its value was highest at the center of the weld, but decreased along the direction perpendicular to the weld. These results can serve as useful guide for actual welding design. K EYWORDS . T joint; Residual stress; Welding deformation; Finite element method. Citation: Wang, XM., Guo, EF., Numerical Analysis and Verification of Residual Stress in T Joint of S355 Steel, Frattura ed Integrità Strutturale, 52 (2020) 25-32. Received: 04.08.2020 Accepted: 21.04.2020 Published: 01.04.2020 Copyright: © 2020 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 he main connection mode in steel structure engineering in China is welding connection. This connection method is economical and flexible: it simplifies the structural details, saves materials and improves production efficiency [1]. Welding connection has been widely used in ship, locomotive, vehicle, bridge, boiler and other industrial fields, and also in energy engineering, marine engineering, aerospace engineering, petrochemical engineering, large plants and high-rise buildings [2-5]. T joint is a common joint in welding. Residual stress and welding deformation are important factors that affect the accuracy and performance of welding products [6,7]. Welding deformation and residual stress affect mechanical properties such as resistance to corrosion and crack growth, and fatigue strength [8,9]. Moreover, they have tremendous impact on the physical and mechanical properties of materials. T joint is one of main structures of bogie beam components, and its welding residual stress affects the load-carrying capacity, fatigue strength, structural stiffness and dimensional precision of bogie beam. In recent years, a large number of scholars in China and elsewhere have studied the prediction and control of post-weld deformation and residual stress. Wudi et al. [10] tested the residual stress in Q345 steel welded with MAG, and compared T