Hello,
I am now trying to solve the thermoelasticity problem using libmesh. I modified ex3 of reduced_basis by adding the temperature as a variable and by adjusting the matrixes. I started from a simple steady case of a cuboid. Its left side is clamped and the temperature there is fixed at 0 degree while there is a heat flux entering on the right side. The heat flux is set as the only parameter. It works well but I encountered problems when imposing a non-zero temperature on the left. At the beginning, I tried penalty method and intended to set the boundary temperature as a parameter. Therefore, I add a new matrix and a new vector in assembly.c. These two objects are defined as boundary_assembly and the terms are calculated like in ex3 of introduction. However, a convergence error occurs: ============================================================================ ==================================== Assembling affine operator 1 of 2 Assembling affine operator 2 of 2 Assembling affine vector 1 of 2 Assembling affine vector 2 of 2 Convergence error. Error id: -3 Stack frames: 8 0: libMesh::print_trace(std::ostream&) 1: libMesh::MacroFunctions::report_error(char const*, int, char const*, char const*) 2: libMesh::RBConstruction::check_convergence(libMesh::LinearSolver<double>&) 3: libMesh::RBConstruction::compute_Fq_representor_innerprods(bool) 4: libMesh::RBConstruction::train_reduced_basis(bool) 5: ./Thermoelasticity-opt() [0x41df39] 6: __libc_start_main 7: ./Thermoelasticity-opt() [0x41e77d] [0] src/reduced_basis/rb_construction.C, line 2124, compiled Jan 6 2018 at 16:42:44 Then I turned to another method. I created a DirichletBoundary object and add it to the map just like ex4 of introduction except that I defined a function that returns a constant instead of the "exact_solution": ============================================================================ ============================================================================ =========================== std::set<boundary_id_type> boundary_ids; boundary_ids.insert(BOUNDARY_ID_MIN_X); // Create a vector storing the variable numbers which the BC applies to std::vector<unsigned int> variables(4); variables[0] = T_var; std::vector<unsigned int> variables_displacement(3); variables_displacement[0] = u_var; variables_displacement[1] = v_var; variables_displacement[2] = w_var; ZeroFunction<> zf; AnalyticFunction<> fun_object(fun_wrapper); DirichletBoundary dirichlet_bc(boundary_ids, variables, fun_object); DirichletBoundary dirichlet_bc_displacment(boundary_ids, variables_displacement, zf); get_dof_map().add_dirichlet_boundary(dirichlet_bc); get_dof_map().add_dirichlet_boundary(dirichlet_bc_displacement); ============================================================================ ===================================== in rb_classes.h. The code runs well but when I check the output, I find that the temperature on the left remains 0 instead of the value I set in the constant function. I would like to know whether my methods are right or not. If not, could you please tell me where the error is and show me other possible solution? Thanks a lot for your kindness. Best regards, Gauvain ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
