Strand buckling analysis under large electromagnetic force by using structural mechanics and strand trace measurement

2013 Fiscal Year Final Research Report

• Project/Area Number: 24760700
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Nuclear fusion studies
• Research Institution: Sophia University
• Principal Investigator: YAGAI Tsuyoshi 上智大学, 理工学部, 准教授 (60361127)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Keywords: 核融合 / ケーブル・イン・コンジット導体 / Nb3Sn / 曲げ歪み / 熱収縮応力 / 座屈 / 超電導特性劣化

Research Abstract

The Cable-In-Conduit conductor is commonly used as the most promising one for large-scale fusion magnets, which consists of twisted strands and sub-cables inserted into the metal case called conduit. During test campaign to evaluate the temperature margin for the assessment of the conductor performance, the temperature margin was getting worse as the number of transport current cycle increases. According to the visual inspection of the conductor, strand buckling due to strand movement might cause the deterioration. In order to investigate the mechanism of the buckling, I calculated the strand movement by using structural mechanics. The results showed the slip motion due to thermal contraction force would cause the displacement. Experimental investigation for certification of the slip distance carried out and its result supported the slip obtained by the calculation. The results will useful for the development of the conductor design activities for large scale magnets.

Research Products

• [Journal Article] Thermal Stability of Butt Joint for CS Conductor in JT-605A (2014)
  • Author(s): T. Takao, Y. Kawahara, K. Nakamura, Y. Yamamoto, T. Yagai, H. Murakami, K. Yoshida, K. Natsume, S. Hamaguchi, T. Obana, K. Takahata, S. Imagawa, T. Mito
  • Journal Title: IEEE Transaction on Applied Superconductivity Volume: vol.24, no.3 Pages: pp4800804
  • Peer Reviewed
• [Journal Article] Study on Resistance Distribution Between Superconducting Strand and a Copper Sleeve in a CICC Joint Considering Three-Dimensional Strand Path (2014)
  • Author(s): T. Morimura, D. Miyagi, M. Tsuda, T. Hamajima, T. Yagai, Y. Nunoya, N. Koizumi, K. Takahata, T. Obana
  • Journal Title: IEEE Transaction on Applied Superconductivity Volume: vol.24, no.3 Pages: pp.4801404
  • Peer Reviewed
• [Journal Article] Investigation of Frictional Force Applied to Strands Surrounded by Other Strands and Tribological Analysis of Contact Surface in CIC Conductor (2014)
  • Author(s): T.Yagai, H. Kudo, K. Hamano, K. Yoshida, S. Hamaguchi, K. Natsume, T. Obana
  • Journal Title: IEEE Transaction on Applied Superconductivity Volume: vol.24, no.3 Pages: pp.8800404
  • Peer Reviewed
• [Journal Article] Theoretical and experimental analysis of Nb3Sn strand buckling in large scale CIC conductor (2014)
  • Author(s): H. Kudo, T. Yagai, K. Hamano, K. Yoshida, K. Natsume, S. Hamaguchi, T. Obana
  • Journal Title: Fusion Engeering and Design Volume: (出版決定)
• [Journal Article] Buckling Analysis of Nb3Sn Strand for Large Scale Cable-In-Conduit Conductor (2013)
  • Author(s): T.Yagai, K. Yoshida, K. Hamano
  • Journal Title: IEEE Transaction On Applied Superconductivity Volume: vol.23, no.3 Pages: pp.4802504
  • Peer Reviewed
• [Journal Article] AC Loss of Nb3Sn Butt Joint for JT-60SA Central Solenoid (2013)
  • Author(s): K. Nakamura, Y. Kawahara, T. Takao, T. Yagai, H. Murakami, K. Yoshida, T. Obana, K. Takahata
  • Journal Title: IEEE Transaction On Applied Superconductivity Volume: vol.23, no.3 Pages: pp.4200304
  • Peer Reviewed
• [Journal Article] Comparison of Analytical Estimation and 3-D Measurement of All Strands Location in CIC Conductor (2013)
  • Author(s): D. Miyagi, S. Nakazawa, D. Arai, T. Morimura, M. Tsuda, T. Hamajima, T. Yagai, N. Koizumi, Y. Nunoya, K. Takahata, T. Obana
  • Journal Title: IEEE Transaction on Applied Superconductivity Volume: vol.23, no.3 Pages: pp.8400904
  • Peer Reviewed
• [Journal Article] Curvature Analysis of Nb3Sn Strands in React and Wind CIC Conductor for Fusion Magnets (2012)
  • Author(s): T. Yagai, S. Nakazawa, M. Tsuda, T. Hamajima
  • Journal Title: IEEE Transaction on Applied Superconductivity Volume: vol.22, no.3 Pages: pp4802304
  • Peer Reviewed
• [Journal Article] Optimal Pitch Analysis Governing Cotnact Strand Number and Lengths With Cu Sleeves at CIC Joints (2012)
  • Author(s): S. Nakazawa, S, Teshima, D. Arai, D.Miyagi, M. Tsuda, T. Hamajima, T. Yagai, Y. Nunoya, N. Koizumi, K. Takahata, T. Obana
  • Volume: vol.22, no.3
  • Pages: pp.4802004
  • Peer Reviewed
• [Journal Article] Analysis of 3-D locations of All Strands in CIC Conductor (2012)
  • Author(s): D. Miyagi, S. Teshima, S. Nakazawa, D. Arai, M. Tsuda, T. Hamajima, T. Yagai, N. Koizumi, Y. Nunoya, , K. Takahata, T. Obana
  • Volume: vol.22, no.3
  • Pages: pp.4802104
  • Peer Reviewed
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