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Design Optimization for Shear Key on the TF Coil Structure of the KSTAR Tokamak

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The KSTAR Tokamak is comprised of a magnet system, vacuum vessel, and cryostat, thereby facilitating vacuum conditions for plasma gas at high temperatures, along with low-temperature helium gas for cooling. The TF coil structure, a part of the magnet system, is constructed and jointed with 16 pieces at 22.5-degree intervals using a conical bolt and shear key. The main function of the shear key in the inner and outer inter-coil structures is to resist in-plane and out-of-plane forces and to increase the shear stiffness for the inter coil structures. However, since the shape of the shear key is difficult to produce and can incur high costs, the shear key needs to be dimensionally optimized to regularize the stress between the key and the structure. Accordingly, shape optimization of the shear key was carried out using the Taguchi method and the stresses analyzed by ANSYS.

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  1. 1.

    C. H. Choi, TF Coil Structure Design, Korea Basic Science Institute.

  2. 2.

    G. S. Lee, J. Kim, S. M. Hwang, et al., “The design of the KSTAR Tokamak,” Fusion Eng. Des., 46, 405–411 (1999).

  3. 3.

    Y. W. Lee, H. J. Ahn, and Y. S. Chang, Global Structural Analysis of TF Magnet, Hyundai Heavy Industries Co., Ltd., Korea Basic Science Institute (2001).

  4. 4.

    B. J. Hamrock, B. O. Jacobson, and S. R. Schmid, Fundamentals of Machine Elements, McGraw-Hill, New York (1999).

  5. 5.

    J. E. Shigley and C. R. Mischke, Mechanical Engineering Design, 5th edition, McGraw-Hill (1989).

  6. 6.

    K. J. Bathe, Finite Element Procedures, Prentice-Hall (1996).

  7. 7.

    S. Erdin and V. L. Pokrovsky, “Oscillations of spherical and cylindrical shells,” Int. J. Mod. Phys. B, 15, No. 23, 3099–3105 (2001).

  8. 8.

    G. Taguchi, Quality Engineering at Development & Design Step, KISA (1991).

  9. 9.

    G. Taguchi and S. Chowdhury, Robust Engineering, Learn How to Boost Quality While Reducing Cost & Time to Market, McGraw-Hill (1999).

  10. 10.

    L. Gaul and C. A. Brebbia, Computational Methods in Contact Mechanics IV, WIT Press (1999).

  11. 11.

    P. K. Maiti and D. Chowdhury, “Discrete solid-on-solid model of interface with bending rigidity: restricted and unrestricted step sizes,” Int. J. Mod. Phys. B, 12, No. 14, 1531–1538 (1998).

  12. 12.

    R. D. Cook, D. S. Malkus, and M. E. Plesha, Concepts and Applications of Finite Element Analysis, 3rd edition, John Wiley & Sons, New York (1989).

  13. 13.

    Y. D. Kwon, N. S. Goo, and B. S. Lim, “Resolution of defects in degenerated shell elements through modification of Gauss integration,” Int. J. Mod. Phys. B, 17, No. 8–9, 1877–1883 (2003).

  14. 14.

    Y. D. Kwon, N. S. Goo, and T. H. Yun, “Non-conforming solid elements for the analysis of bending deformation of isotropic/orthotropic materials with the smallest D.O.F., Int. J. Mod. Phys. B, 17, No. 8–9, 1863–1869 (2003).

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Correspondence to D. S. Lee.

Additional information

Translated from Problemy Prochnosti, No. 1, pp. 39 – 46, January – February, 2016.

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Lee, D.S., Kwon, Y.D. & Han, J.S. Design Optimization for Shear Key on the TF Coil Structure of the KSTAR Tokamak. Strength Mater 48, 32–38 (2016).

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  • Taguchi method
  • optimization
  • shear key
  • TF (toroidal field) coil structure