Study on Influence of Repeated Hoop Stresses on HTS Wires in Coils

Author

Sasaki, Erika ; Isozaki, Kousuke ; Iwasaki, Shoichi ; Anazawa, Takao ; Nakayama, Daiki ; Ariyama, Takahiro ; Takao, Tomoaki ; Tsukamoto, Osami

Author_Institution

Sophia Univ., Tokyo, Japan

Volume

25

Issue

3

fYear

2015

fDate

42156

Firstpage

1

Lastpage

5

Abstract

HTS wires in coils are subjected to hoop stresses due to electro magnetic forces and thermal contractions. Influence of repeated and non-repeated hoop stresses is investigated by making an experimental apparatus to apply hoop stresses mechanically to dry (non impregnated) and epoxy-impregnated HTS test coils. In the experiment it was found that a critical current of a dry coil was more degraded by the hoop stresses than that of an epoxy-impregnated coil. In the paper, distribution of hoop stresses to layers in HTS coils are investigated and based on the experimental results, differences of critical current degradations of dry and impregnated coils are studied.

Keywords

bismuth compounds; calcium compounds; critical currents; high-temperature superconductors; silver; strontium compounds; superconducting coils; superconducting tapes; Bi₂Sr₂Ca₂Cu₃O_10+x-Ag; HTS wires; critical current; critical current degradations; dry coil; electromagnetic forces; epoxy-impregnated HTS test coils; repeated hoop stresses; thermal contractions; Coils; Critical current density (superconductivity); Force; High-temperature superconductors; Strain; Stress; Wires; Bi/Ag-sheathed wire; Critical current; Dry coil; Hoop stress; Impregnated coil; critical current; dry coil; hoop stress; impregnated coil;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2014.2379913

Filename

6983614