Add capability for hexagonal close packed crystal plasticity

[sapitts]

Reason

After the face centered and body centered cubic crystals (FCC and BCC), the hexagonal close packed (HCP) crystal structure is the most commonly studied in microstructure-based models. The HCP lattice structure is different enough from the cubic lattice structures that new material models are required to study these materials using MOOSE.

Design

Three functionalities should be added to enable rudimentary HCP crystal plasticity modeling capabilities, following work published in the open literature:

• Transformation of 4-index Miller-Bravis notation to 3-index Cartesian system
• Constitutive model for dislocation glide
• Constitutive model for dislocation twinning

Impact

Adding the capability to model the HCP lattice structure to MOOSE's crystal plasticity capabilities will broaden the number of materials that can be studied with MOOSE.

[loganharbour]

@sapitts can this be closed?

[sapitts]

Not quite yet, please. I still need to make a child class for the HCP dislocation twinning and add a set of associated tests for that capability. I will make sure to use the Closes # on that final merge request