Thanks, I just talked with Guido about this. I was under the impression that there may be packages that already have the nonlinear algorithm included in them (making things easier). However, it seems that there are only (or predominantly) linear solvers and we must create a nonlinear algorithm (or are there public domain options?)
Looking at something like MSC Nastran SOL 106, the nonlinear algorithm is not very robust (it tends to be slow and often has a hard time converging). However, ABAQUS has been known to have a much more robust nonlinear solver. Later, MSC purchased MARC because it had a very good nonlinear solver (as opposed to SOL106 and SOL400). So I suspect there is a a basic nonlinear algorithm approach (something like Newton-Raphson or modified Newton-Raphson), but probably also something more more challenging (and effective) than that.
So this begs the question of whether would we would code in Newton-Raphson in or if there are pubic domain codes that could do better?
Looking at something like MSC Nastran SOL 106, the nonlinear algorithm is not very robust (it tends to be slow and often has a hard time converging). However, ABAQUS has been known to have a much more robust nonlinear solver. Later, MSC purchased MARC because it had a very good nonlinear solver (as opposed to SOL106 and SOL400). So I suspect there is a a basic nonlinear algorithm approach (something like Newton-Raphson or modified Newton-Raphson), but probably also something more more challenging (and effective) than that.
So this begs the question of whether would we would code in Newton-Raphson in or if there are pubic domain codes that could do better?