ABSTRACT
Three seemingly different approaches proposed to ameliorate difficulties encountered in the numerical simulation of softening materials are examined from a unified perspective. It is shown that techniques employing a mesh-dependent softening modulus, certain non-local softening models, and rate dependent models correspond to alternative non-local regularization procedures of the dissipation function. For the viscoplastic regularization, hyperbolicity of the incremental (regularized) algorithmic problem does not hold if certain critical time step is violated.
