A comparison of the primal and semi-dual variational formats of gradient-extended crystal inelasticity
Journal article, 2017

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 displacements, the slip of each slip system and the dissipative stresses as the primary unknown fields. An alternative format is coined the semi-dual format, which in addition includes energetic microstresses among the primary unknown fields. We compare the primal and semi-dual variational formats in terms of advantages and disadvantages from modeling as well as numerical viewpoints. Finally, we perform a series of representative numerical tests to investigate the rate of convergence with finite element mesh refinement. In particular, it is shown that the commonly adopted microhard boundary condition poses a challenge in the special case that the slip direction is parallel to a grain boundary.

Crystal plasticity

Gradient enhanced continuum

Semi-dual format

Author

Kristoffer Carlsson

Chalmers, Applied Mechanics, Material and Computational Mechanics

Kenneth Runesson

Chalmers, Applied Mechanics, Material and Computational Mechanics

Fredrik Larsson

Chalmers, Applied Mechanics, Material and Computational Mechanics

Magnus Ekh

Chalmers, Applied Mechanics, Material and Computational Mechanics

Computational Mechanics

0178-7675 (ISSN) 1432-0924 (eISSN)

Vol. 60 4 531-548

Subject Categories

Metallurgy and Metallic Materials

Areas of Advance

Materials Science

DOI

10.1007/s00466-017-1419-y

More information

Latest update

4/19/2018