Dear Zhenghuai Guo, Why don't you use a direct solver (MUMPS)? Direct solvers are much more robust, especially if your model contains Lagrange multipliers.
BR Kostas On Thu, May 2, 2019 at 2:57 PM Zhenghuai Guo <[email protected]> wrote: > Hi, Andriy and Yves and Konstantinos, > > I loaded two meshes, totally about 350000 elements. > > I only added elasticity bricks: > getfem::add_isotropic_linearized_elasticity_brick(model, mim_1, "u_1", > "lambda_1", "mu_1"); > getfem::add_isotropic_linearized_elasticity_brick(model, mim_2, "u_2", > "lambda_2", "mu_2"); > > > and four pointwise_constraints (two more each mesh): > > getfem::add_pointwise_constraints_with_multipliers(model,"u_1","point_1_1","point_1_1_unitx", > "point_1_1_valuex"); > > getfem::add_pointwise_constraints_with_multipliers(model,"u_1","point_1_1","point_1_1_unity", > "point_1_1_valuey"); > > getfem::add_pointwise_constraints_with_multipliers(model,"u_1","point_1_2","point_1_2_unitx", > "point_1_2_valuex"); > > getfem::add_pointwise_constraints_with_multipliers(model,"u_1","point_1_2","point_1_2_unity", > "point_1_2_valuey"); > > getfem::add_pointwise_constraints_with_multipliers(model,"u_2","point_2_1","point_2_1_unitx", > "point_2_1_valuex"); > > getfem::add_pointwise_constraints_with_multipliers(model,"u_2","point_2_1","point_2_1_unity", > "point_2_1_valuey"); > > getfem::add_pointwise_constraints_with_multipliers(model,"u_2","point_2_2","point_2_2_unitx", > "point_2_2_valuex"); > > getfem::add_pointwise_constraints_with_multipliers(model,"u_2","point_2_2","point_2_2_unity", > "point_2_2_valuey"); > > The values for the pointwise_constraints are simply the same as -1. This > means the two meshes should just be translated parallelly by -1 in both x > and y direction. > > My solver is > gmm::iteration iter(1E-9, 1, 100); > getfem::standard_solve(model, iter); > > > But I get warning of not convergence: > iter 0 residual 1 > iter 500 residual 6.17288e-05 > Level 2 Warning in getfem/getfem_model_solvers.h, line 127: gmres did not > converge! > > I am quite sure that my mesh looks good and have no strange shape > elements. When I use small simply meshes, the code runs ok. > Could you please advise to me how to improve? > > Regards > Zhenghuai Guo > >
