Velocity versus Displacement

[ClarkMyWords]

Create helper routines to allow for simple input .toml/.json files with a prescribed compression/tension/etc. distance, and derive required velocities from those

[ClarkMyWords]

I think this was actually as simple as having the user give an array of displacements (N for the number of loading conditions: 1 for simple tension/compression, 2 for biaxial, 3 for triaxial, etc.), and then deriving velocity based on the total simulation time from that. Anything beyond that is, near as I can tell, a limitation of the UMAT format.

[ClarkMyWords]

July 2024: I think this is finished? Needs testing