def _create_mechanical_solution_strategy(self):
solution_scheme = self.get_solution_scheme()
eigen_solver = self.get_builder_and_solver_eigen(
) # The eigensolver is created here.
builder_and_solver = self.get_builder_and_solver(
) # The linear solver is created here.
convergence_criteria = self.get_convergence_criterion()
computing_model_part = self.GetComputingModelPart()
buckling_settings = self.settings["buckling_settings"]
return StructuralMechanicsApplication.PrebucklingStrategy(
computing_model_part, solution_scheme, eigen_solver,
builder_and_solver, convergence_criteria,
self.settings["max_iteration"].GetInt(), buckling_settings)
def _solve_prebuckling_problem(self, mp, NumOfNodes, iterations, echo=0):
eigensolver_settings = KratosMultiphysics.Parameters("""
{
"max_iteration" : 1000,
"tolerance" : 1e-6,
"number_of_eigenvalues" : 1,
"echo_level" : 0,
"normalize_eigenvectors": false
}
""")
buckling_settings = KratosMultiphysics.Parameters("""
{
"initial_load_increment" : 1.0,
"small_load_increment" : 0.0005,
"path_following_step" : 0.5,
"convergence_ratio" : 0.005,
"make_matrices_symmetric" : true
}
""")
eigen_solver = EigenSolversApplication.EigensystemSolver(
eigensolver_settings)
eigen_solver_ = KratosMultiphysics.ResidualBasedEliminationBuilderAndSolver(
eigen_solver)
convergence_criterion = KratosMultiphysics.DisplacementCriteria(
1e-4, 1e-9)
scheme = KratosMultiphysics.ResidualBasedIncrementalUpdateStaticScheme(
)
linear_solver = KratosMultiphysics.SkylineLUFactorizationSolver()
builder_and_solver = KratosMultiphysics.ResidualBasedEliminationBuilderAndSolver(
linear_solver)
convergence_criterion.SetEchoLevel(echo)
eig_strategy = StructuralMechanicsApplication.PrebucklingStrategy(
mp, scheme, eigen_solver_, builder_and_solver,
convergence_criterion, 10, buckling_settings)
eig_strategy.SetEchoLevel(echo)
LoadFactor = []
for i in range(iterations):
eig_strategy.Solve()
if (i % 2 == 1):
LoadFactor.append(mp.ProcessInfo[
StructuralMechanicsApplication.EIGENVALUE_VECTOR][0])
self._updateConditions(mp, NumOfNodes)
return LoadFactor
