A strain localization analysis using a viscoplastic softening model for clay
The authors consider the undrained creep problem, in which deviatoric stress components are constant, the volumetric strain is zero, while the mean effective stress may be relaxed, in the framework of elasto-viscoplastic constitutive models for clay. The instability of the proposed problem is evaluated, and the critical stress ratio for the appropriate evolution equation is found to be the transition point between the stable and unstable regions in the Lyapunov sense. In a two-dimensional motion under plane strain undrained conditions, the preferred orientation of the localized zone (where infinitesimal periodic non-uniformities will grow in a homogeneous motion) is determined. From the numerical results performed by finite element method using the updated Lagrangian scheme, the authors found that the viscoplastic softening model can describe strain localization phenomena such as shear banding.
scientific article; zbMATH DE number 834222