Numerical study of stress and plastic strain evolution under compression and shear of a sample in a rotational anvil cell

The large-strain problem on the evolution of distribution of the components of stress tensor and plastic strain in a sample under compression and torsion in a rotational anvil cell was formulated and studied in detail using the FEM. Results are obtained for compression by different axial forces and torsion under two different constant axial forces. The effects of redistribution of the friction radial and torsional stresses and the load on a sample and gasket on the resultant fields are elucidated. Small pressure self-multiplication effect is revealed during torsion after compression below some critical force, and significant heterogeneity of all fields is found. Strong shear strain localization near the contact surface between sample and anvil is quantified. Results are compared with the simplified solution and available experiments. The results obtained are important for the determination of elastic and plastic properties of materials under high pressure and for the interpretation of kinetics of strain-induced phase transformations and chemical reactions.