Compression-Fatigue, Elastic Modulus, and Thermal Contraction of Insulated Conduit Arrays of ITER CS Modules

Published

July 3, 2013

Author(s)

Richard Reed, Robert Walsh, Dash Weeks, Joseph D. McColskey, N. N. Martovsky

Abstract

Compression-fatigue tests at ∼77 K were conducted to compare two insulation systems (epoxy resin impregnated glass/Kapton) for use in the ITER central solenoid modules. Test samples consisted of insulated conduits that were stacked in 4×4 arrays. The thermal contraction (295-77 K) prior to fatigue, elastic modulus during fatigue, and the structural integrity of the insulation were measured and assessed at the National Institute of Standards and Technology large-scale test facilities. The maximum cyclic stress of 72 MPa, minimum stress of 25 MPa, and 1.2 × 106 cycles were used to comply with ITER design objectives. Thermal contraction between 295 and 77 K and the elastic modulus were measured using strain gages and strain-gage extensometers. Calibration of the strain was obtained through the use of an equivalent-size block of 6061-T6 aluminum alloy with known thermal contraction and elastic moduli. Following fatigue, the arrays were cross-sectioned and optically examined for resin-impregnation quality and fatigue cracking tendencies of the insulation systems. The thermal contraction and elastic modulus of cross-sectioned samples were remeasured at the National High Magnetic Field Laboratory for property confirmation, using different techniques.

Citation

IEEE Transactions on Applied Superconductivity

Volume

23

Issue

3

Pub Type

Journals

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DOI Link

Keywords

Compression fatigue, elastic modulus, glass/epoxy composite, thermal contraction, turn insulation.

Citation

Reed, R. , Walsh, R. , Weeks, D. , McColskey, J. and Martovsky, N. (2013), Compression-Fatigue, Elastic Modulus, and Thermal Contraction of Insulated Conduit Arrays of ITER CS Modules, IEEE Transactions on Applied Superconductivity, [online], https://doi.org/10.1109/TASC.2013.2237940 (Accessed October 9, 2025)