Hi, I implement a rather complicated nonlinear problem using in the similar way to step 40. I used the fixed point iteration, stopping criterion is the residual of the equation. I have set non homogeneous and homogeneous Dirichlet boundary conditions on parts of boundary. I checked the assembly and solve of system and assembly of residual several times, but my residual remains constant after few iterations.
I have noticed, that in several tutorial steps is some treatment of residuals in constrained dofs https://www.dealii.org/8.4.1/doxygen/deal.II/step_15.html#MinimalSurfaceProblemcompute_residual and in https://www.dealii.org/8.4.1/doxygen/deal.II/step_42.html#PlasticityContactProblemsolve_newton is the following code for (unsigned int n = start_res; n < end_res; ++n) if (all_constraints.is_inhomogeneously_constrained(n)) residual(n) = 0; Could You tell me please a principle, how to assemble residual in the similar way the matrix and rhs is assembled in step 40. I guess, that is is necessary to treat somehow the constrained degrees of freedom with Dirichlet boundary conditions. Thank You Marek C -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
