Make ReinforcedFiber model support St. Venant-Kirchhoff parameterization
Description
The St. Venant-Kirchhoff material model is the natural, non-linear extension of the linear elasticity model. It would therefore be useful for simulations with large local deformations, where linear elasticity is not applicable anymore, while retaining the material properties of the linear model.
The non-linear model requires an iterative Newton solver whose parameters have to be tuned to the problem. Also, the solver might not converge. A suitable initial condition is required. Possibly, a solution of the linear problem can be used.
Proposal
- Enable the St. Venant-Kirchhoff model for the bulk material of the fiber-reinforced local operator.
- Ensure that the model is correctly parameterized.
- Employ a Newton solver.
- Add a run test for the model.