H-adaptive finite element analysis for localization phenomena with reference to metal powder forming

Standard finite element models, i.e. finite element methods that use standard constitutive models, suffer from excessive mesh dependence when strain-softening models are used in numerical analyses and cannot reproduce the size effect commonly observed in quasi-brittle failure. In this paper, an h-adaptive analysis for the mixed finite element solution of solid mechanics problems is presented with special reference to metal powder forming involving localization due to material instability. A remeshing strategy is employed to compute the distribution of required element size using the estimated error distribution. The numerical results are obtained for a Von-Mises yield criterion applied to a multi-level component, at the final stage of compaction. It shows how adaptive remeshing techniques can be applied to improve the definition of the shear band, using a non-local constitutive model to avoid loss of mesh objectivity.