The normal and shear strains obtained in torsion shear tests may be interpreted in two different ways to gain insight into (1) the type of plastic potential to be employed in hardening plasticity stress-strain models, and (2) the coincidence in physical space of the plastic strain increment directio
Failure of Alumina in Torsion Tests
✍ Scribed by Thomas Schwind; Stefan Fünfschilling; Eberhard Kerscher; Karl-Heinz Lang; Rainer Oberacker; Michael J. Hoffmann; Theo Fett
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 287 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1438-1656
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Fatigue behavior under cyclic torsion loading shows a complicated dependency between the number of cycles to failure N~f~ and the height of the applied load σ~appl~. A recently published result is chosen for which three clearly different regions are observed in which the normally straight log(N~f~)‐log(σ) plot shows different slopes. Whereas the high‐stress region near the torsion strength can be interpreted as normal mode‐I failure of randomly oriented surface cracks, the steep part may be understood as the consequence of friction degradation at grinding cracks which are under pure mode‐II and mode‐III loading. At lowest loads, quasi‐static subcritical crack growth support has to be expected with its commonly higher load exponents.
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