COMPUTATIONAL ISSUES OF GRADIENT-EXTENDED CRYSTAL INELASTICITY

Paper i proceeding, 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.