DOI QR코드

DOI QR Code

Delamination behaviors of GdBCO CC tapes under different transverse loading conditions

  • Gorospe, Alking B. (Department of Mechanical Design Engineering, Andong National University) ;
  • Bautista, Zhierwinjay M. (Department of Mechanical Design Engineering, Andong National University) ;
  • Shin, Hyung-Seop (Department of Mechanical Design Engineering, Andong National University)
  • Received : 2015.08.27
  • Accepted : 2015.09.18
  • Published : 2015.09.30

Abstract

In superconducting coil applications particularly in wet wound coils, coated conductor (CC) tapes are subjected to different type of stresses. These include hoop stress acting along the length of the CC tape and the Lorentz force acting perpendicular to the CC tape's surface. Since the latter is commonly associated with delamination problem of multi-layered CC tapes, more understanding and attention on the delamination phenomena induced in the case of coil applications are needed. Difference on the coefficient of thermal expansion (CTE) of each constituent layer of the CC tape, the bobbin, and the impregnating materials is the main causes of delamination in CC tapes when subjected to thermal cycling. The CC tape might also experience cyclic loading due to the energizing scheme (on - off) during operation. In the design of degradation-free superconducting coils, therefore, characterization of the delamination behaviors including mechanism and strength in REBCO CC tapes becomes critical. In this study, transverse tensile tests were conducted under different loading conditions using different size of upper anvils on the GdBCO CC tapes. The mechanical and electromechanical delamination strength behaviors of the CC tapes under transverse tensile loading were examined and a two-parameter Weibull distribution analysis was conducted in statistical aspects. As a result, the CC tape showed similar range of mechanical delamination strength regardless of cross-head speed adopted. On the other hand, cyclic loading might have affected the CC tape in both upper anvil sizes adopted.

Keywords

References

  1. A. L. Mbaruku and J. Schwartz, "Fatigue behavior of Y-Ba-Cu-O/hastelloy-C coated conductor at 77 K," IEEE Trans. Appl. Supercond., vol. 18, pp. 1743-1752, 2008. https://doi.org/10.1109/TASC.2008.2003491
  2. T. Takematsu et al., "Degradation of the performance of a YBCO-coated conductor double pancake coil due to epoxy impregnation," Physica C, vol. 470, pp. 674-677, 2010. https://doi.org/10.1016/j.physc.2010.06.009
  3. D. C. van der Laan, J. W. Ekin, C. C. Clickner, and T. C. Stauffer, "Delamination strength of YBCO coated conductors under transverse tensile stress," Supercond. Sci. Technol., vol. 20, pp. 765-770, 2007. https://doi.org/10.1088/0953-2048/20/8/007
  4. G. Majkic, E. Galstyan, Y. Zhang and V. Selvamanickam, "Investigation of delamination mechanisms in IBAD-MOCVD REBCO coated conductors," IEEE Trans. Appl. Supercond., vol. 23, pp. 6600205, 2013. https://doi.org/10.1109/TASC.2012.2237496
  5. H. S. Shin and A. Gorospe, "Characterization of transverse tensile stress response of critical current and delamination behavior in GdBCO coated conductor tapes by anvil test," Supercond. Sci. Technol., vol. 27, pp. 025001, 2014. https://doi.org/10.1088/0953-2048/27/2/025001
  6. N. Sakai, S. Lee, N. Chikumoto, T. Izumi, and K. Tanabe, "Delamination behavior of Gd123 coated conductor fabricated by PLD," Physica C, vol. 471, pp. 1075-1079, 2011. https://doi.org/10.1016/j.physc.2011.05.127
  7. Y. Yanagisawa et al., "Remarkable weakness against cleavage stress for YBCO-coated conductors and its effect on the YBCO coils performance," Physica C, vol. 471, pp. 480-485, 2011. https://doi.org/10.1016/j.physc.2011.05.003
  8. A. Gorospe, A. Nisay, and H. S. Shin, "Delamination behaviour in differently copper laminated REBCO coated conductor tapes under transverse loading," Physica C, vol. 504, pp. 49-52, 2014.
  9. H. S. Shin, A. Gorospe, Z. Bautista, and M. Dedicatoria, "Evaluation of electromechanical properties in GdBCO coated conductor tapes under cyclic loading and bending," Supercond. Sci. Technol., submitted for publication.
  10. E. Barbero, J. Fernandez-Saez, and C. Navarro, "Statistical analysis of the mechanical properties of composite materials," Composites: Part B: Engineering, vol. 31, pp. 375-381, 2000. https://doi.org/10.1016/S1359-8368(00)00027-5
  11. M. H. Dirikolua, A. Aktas, and B. Birgoren, "Statistical analysis of fracture strength of composite materials uwing Weibull distribution," Turkish J. Eng. Env. Sci., vol. 26, pp. 45-48, 2000.
  12. R. V. Curtis and A. S. Juszczyk, "Analysis of strength data using two-and-three-parameter Weibull models," J. Mater. Sci., vol. 33, pp. 1151-1157, 1998.
  13. A. J. Hallinan Jr., "A review of the Weibull distribution," J. Qual. Technol., vol. 25, pp. 85-93, 1993.
  14. S. Ochiai et al., "Applicability of Weibull distribution of distributed normalized critical current of bent-damaged Bi2223 composite tape," Mater. Trans., vol. 51, pp. 1663-1670, 2010. https://doi.org/10.2320/matertrans.MAW201001
  15. J. R. Dizon, A. Gorospe, and H. S. Shin, "Numerical analysis of stress distribution in Cu-stabilized GdBCO CC tapes during anvil tests for the evaluation of transverse delamination strength," Supercond. Sci. Technol., vol. 27, pp. 055023, 2014. https://doi.org/10.1088/0953-2048/27/5/055023

Cited by

  1. Investigation on quench initiation and propagation characteristics of GdBCO coil co-wound with a stainless steel tape as turn-to-turn metallic insulation vol.87, pp.11, 2016, https://doi.org/10.1063/1.4966676
  2. Evaluation of delamination characteristics in GdBCO CC tapes under transverse load using anvil test methods for various anvil contact configurations at 77 K vol.32, pp.10, 2019, https://doi.org/10.1088/1361-6668/ab3151