Cryogenics 45, 606-616
D. Pahr¹, H.J. Böhm¹, K. Humer² and H.W. Weber²
¹ Institute of Lightweight Design and Structural
TU Wien, ² Atomic Institute of the Austrian Universities,
Insulation systems are critical components of the International Thermonuclear
Experimental Reactor (ITER).
They must meet the super conducting magnets design requirements, including
mechanical strength under combined shear and compressive stresses at cryogenic
Past cryogenic magnet systems often relied on woven glass/epoxy materials for
An important point is to find a reliable shear/compression test method for
The present work investigates a commonly used shear/compression setup and
aims at measuring the reliability of the obtained test results.
Therefore, the stress and failure analysis is performed analytically and
numerically using the finite element method.
The model is based on woven glass fiber reinforced materials which are
subjected to combined shear and compressive stresses as well as to thermal
loading, that results from cooling from 293 K to the test temperature of 77 K.
A short analytical section shows the problems of common failure criteria which
are used to describe the interaction of the shear and compression stresses.
The numerical - finite element - section is based on three-dimensional linear
elastic finite element models under thermo-mechanical loading.
The locations of high stress gradients are investigated using an average stress
Three different model geometries (15 deg, 45 deg, and 70 deg) are analyzed and
finally compared with respect to their reliability.