Modeling of monotonic and cyclic Swift effect using anisotropic finite viscoplasticity theory based on overstress (AFVBO): Part II - Numerical experiments

Anisotropic finite VBO given in Part I is used to model monotonic and cyclic Swift effects. The simulations were performed for fixed and deformation induced anisotropy. In the case of fixed anisotropy, it is assumed that the material is orthotropic. Material investigated at the fixed anisotropy is rolled copper. In the case of deformation induced anisotropy, the behavior of 70:30 brass under free-end torsion is investigated. The material is chosen as isotropic in the beginning of the deformation and allowed to evolve under large shear deformation. The simulation results are compared with experimental data obtained by Swift [Engineering 163 (1947) 253]. The Jaumann rate and the logarithmic rate are chosen as objective rates in the simulations. It is shown that anisotropic finite VBO can reproduce the monotonic and cyclic Swift effect quantitatively.