COMPUTATIONAL ISSUES OF GRADIENT-EXTENDED CRYSTAL INELASTICITY

. In this paper we discuss issues related to the theoretical as well as the computationalformat of gradient-extended crystal viscoplasticity. The so-called “primal”format uses the internal variables and the displacements as the primary unknown fields.An alternative format is coined the “semi-dual format”, which in addition includes microstresses,thereby defining a mixed variational problem. We compare the primal andsemi-dual variational formats in terms of pros and cons from a modeling as well as anumerical viewpoint. We perform a set of numerical benchmarks to investigate the rateof convergence for errors in different norms