COMPUTATIONAL ISSUES OF GRADIENT-EXTENDED CRYSTAL INELASTICITY
Paper in proceedings, 2016
. In this paper we discuss issues related to the theoretical as well as the computational
format 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 and
semi-dual variational formats in terms of pros and cons from a modeling as well as a
numerical viewpoint. We perform a set of numerical benchmarks to investigate the rate
of convergence for errors in different norms.