def _solve_eigenvalue_problem(self, mp, use_block_builder, echo=0):
eigensolver_settings = KratosMultiphysics.Parameters("""
{
"max_iteration" : 1000,
"tolerance" : 1e-6,
"number_of_eigenvalues" : 2,
"echo_level" : 0,
"normalize_eigenvectors": true
}
""")
eigen_solver = LinearSolversApplication.EigensystemSolver(eigensolver_settings)
if use_block_builder:
builder_and_solver = KratosMultiphysics.ResidualBasedBlockBuilderAndSolver(eigen_solver)
else:
builder_and_solver = KratosMultiphysics.ResidualBasedEliminationBuilderAndSolver(eigen_solver)
eigen_scheme = StructuralMechanicsApplication.EigensolverDynamicScheme()
compute_modal_decomposition = True
# see "structural_mechanics_eigensolver.py", values are for the "EigensystemSolver"
mass_matrix_diagonal_value = 0.0
stiffness_matrix_diagonal_value = 1.0
eig_strategy = StructuralMechanicsApplication.EigensolverStrategy(mp,
eigen_scheme,
builder_and_solver,
mass_matrix_diagonal_value,
stiffness_matrix_diagonal_value,
compute_modal_decomposition)
eig_strategy.SetEchoLevel(echo)
eig_strategy.Solve()
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 = LinearSolversApplication.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
def ConstructSolver(settings):
if not isinstance(settings, KM.Parameters):
raise Exception("Input is expected to be provided as a Kratos Parameters object")
solver_type = settings["solver_type"].GetString()
if solver_type == "eigen_eigensystem":
if kratos_utils.CheckIfApplicationsAvailable("LinearSolversApplication"):
from KratosMultiphysics import LinearSolversApplication
eigen_solver = LinearSolversApplication.EigensystemSolver(settings)
return eigen_solver
else:
raise Exception("LinearSolversApplication not available")
if solver_type == "spectra_sym_g_eigs_shift":
if kratos_utils.CheckIfApplicationsAvailable("LinearSolversApplication"):
from KratosMultiphysics import LinearSolversApplication
eigen_solver = LinearSolversApplication.SpectraSymGEigsShiftSolver(settings)
return eigen_solver
else:
raise Exception("LinearSolversApplication not available")
elif solver_type == "dense_eigensolver":
if kratos_utils.CheckIfApplicationsAvailable("LinearSolversApplication"):
from KratosMultiphysics import LinearSolversApplication
eigen_solver = LinearSolversApplication.DenseEigenvalueSolver(settings)
return eigen_solver
else:
raise Exception("LinearSolversApplication not available")
elif solver_type == "feast":
if kratos_utils.CheckIfApplicationsAvailable("LinearSolversApplication"):
from KratosMultiphysics import LinearSolversApplication
if LinearSolversApplication.HasFEAST():
is_symmetric = settings["symmetric"].GetBool() if settings.Has("symmetric") else True
eigen_solver = LinearSolversApplication.FEASTSymmetricEigensystemSolver(settings) if is_symmetric else LinearSolversApplication.FEASTGeneralEigensystemSolver(settings)
return eigen_solver
else:
raise Exception("FEAST not available in LinearSolversApplication")
else:
raise Exception("LinearSolversApplication not available")
elif solver_type == "feast_complex":
if kratos_utils.CheckIfApplicationsAvailable("LinearSolversApplication"):
from KratosMultiphysics import LinearSolversApplication
if LinearSolversApplication.HasFEAST():
is_symmetric = settings["symmetric"].GetBool() if settings.Has("symmetric") else True
eigen_solver = LinearSolversApplication.ComplexFEASTSymmetricEigensystemSolver(settings) if is_symmetric else LinearSolversApplication.ComplexFEASTGeneralEigensystemSolver(settings)
return eigen_solver
else:
raise Exception("FEAST not available in LinearSolversApplication")
else:
raise Exception("LinearSolversApplication not available")
linear_solver_configuration = settings["linear_solver_settings"]
if linear_solver_configuration.Has("solver_type"): # user specified a linear solver
linear_solver = linear_solver_factory.ConstructSolver(linear_solver_configuration)
else:
linear_solver = linear_solver_factory.CreateFastestAvailableDirectLinearSolver()
if solver_type == "power_iteration_eigenvalue_solver":
eigen_solver = KM.PowerIterationEigenvalueSolver( settings, linear_solver)
elif solver_type == "power_iteration_highest_eigenvalue_solver":
eigen_solver = KM.PowerIterationHighestEigenvalueSolver( settings, linear_solver)
elif solver_type == "rayleigh_quotient_iteration_eigenvalue_solver":
eigen_solver = KM.RayleighQuotientIterationEigenvalueSolver( settings, linear_solver)
else:
raise Exception("Solver type not found. Asking for :" + solver_type)
return eigen_solver