An Alternative Frictional Boundary Condition for Computational Fluid Dynamics Simulation of Friction Stir Welding

Journal Article · Mon Jul 11 00:00:00 EDT 2016 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/s11665-016-2219-9· OSTI ID:1366372

Chen, Gaoqiang ^[1]; Feng, Zhili ^[2]; Zhu, Yucan ^[3]; Shi, Qingyu ^[3]

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1. Tsinghua Univ., Haidian (China). State Key Lab. of Tribology; Tsinghua Univ., Haidian (China). Key Lab. for Advanced Materials Processing Technology, Dept. of Mechanical Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
3. Tsinghua Univ., Haidian (China). State Key Lab. of Tribology; Tsinghua Univ., Haidian (China). Key Lab. for Advanced Materials Processing Technology, Dept. of Mechanical Engineering

For better application of numerical simulation in optimization and design of friction stir welding (FSW), this paper presents a new frictional boundary condition at the tool/workpiece interface for computational fluid dynamics (CFD) modeling of FSW. The proposed boundary condition is based on an implementation of the Coulomb friction model. Using the new boundary condition, the CFD simulation yields non-uniform distribution of contact state over the tool/workpiece interface, as validated by the experimental weld macrostructure. It is found that interfacial sticking state is present over large area at the tool-workpiece interface, while significant interfacial sliding occurs at the shoulder periphery, the lower part of pin side, and the periphery of pin bottom. Due to the interfacial sticking, a rotating flow zone is found under the shoulder, in which fast circular motion occurs. The diameter of the rotating flow zone is smaller than the shoulder diameter, which is attributed to the presence of the interfacial sliding at the shoulder periphery. For the simulated welding condition, the heat generation due to friction and plastic deformation makes up 54.4 and 45.6% of the total heat generation rate, respectively. In conclusion, the simulated temperature field is validated by the good agreement to the experimental measurements.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC05-00OR22725; 51375259
• OSTI ID: 1366372
• Journal Information: Journal of Materials Engineering and Performance, Vol. 25, Issue 9; ISSN 1059-9495
• Publisher: Springer
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
frictional boundary condition
friction stir welding
heat generation
material flow
thermal-mechanical processing condition