Hello, I like to use SNES to solve nonlinear system of equations. For my problem, I have to update some internal variables for computed newtons increments of primary unknowns, before I update residual (right hand side) and Jacobian. I found function SNESSetUpdate which is called at the beginning o every iteration. But I am not sure enough if that function is proper for updating internal variables. Can You advise me if it is right to use internal variables, f.e. increments of plastic strain at gauss points.
Such problems exist in solid mechanics when increment of plastic strain and plastic multiplayer have to be computed. Another example is for hybrid/mixed FE discretisation having some variables approximated with C(-1) continuity. Unknowns associated to C(-1) continuos approximations can be statically condensed , see attached file. As a results at each iteration step increments for statically condense variables have to be updated. Lukasz Kaczmarczyk -------------- next part -------------- A non-text attachment was scrubbed... Name: eq.pdf Type: application/pdf Size: 46799 bytes Desc: not available URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20090930/4c015d1c/attachment-0001.pdf>
