Localization of limited strains

The Considere criterion for plastic instabilities in the tensile test is ex tended to include strain rate sensitivity. In analogy, a stability criterio n for torsion tests on cylindrical specimens is formulated. It takes into a ccount the temperature dependence of flow stress in addition to strain hard ening and strain rate sensitivity. In both experiments the localization of limited strains may lead to new stages of homogeneous deformation.