On the regularization for ductile damage models

Modeling softening behavior often leads to ill‐posed boundary value problems. This, in turn, results in pathological mesh‐dependent computations as far as the finite‐element‐method is concerned. A by now widely used technique to eliminate these problems is the micromorphic approach by [1,2]. This regularization technique implicitly includes gradients of internal variables into the constitutive model. However, and in contrast to other gradient‐enhanced models, the micromorphic approach preserves the local structure of the underlying local constitutive model. Within this contribution, it is first shown that a standard application of this approach to ductile damage models does not work. By analyzing the respective equations, a modification of the regularization technique is elaborated – first for an isotropic ductile damage model, i.e. scalar‐valued damage. Subsequently, the novel regularization is extended to tensor‐valued damage models.