from feastruct.solvers.feasolve import Solver
[docs]class LinearBuckling(Solver):
"""Class for a linear buckling solver.
:cvar analysis: Analysis object to solve
:vartype analysis: :class:`~feastruct.fea.fea.FiniteElementAnalysis`
:cvar analysis_cases: List of analysis cases to solve
:vartype analysis_cases: list[:class:`~feastruct.fea.cases.AnalysisCase`]
:cvar solver_settings: Settings to use in the solver
:vartype solver_settings: :class:`~feastruct.solvers.feasolve.SolverSettings`
:cvar int ndof: Number of degrees of freedom in the analysis
"""
[docs] def __init__(self, analysis, analysis_cases, solver_settings=None):
"""Inits the LinearBuckling class.
:param analysis: Analysis object to solve
:type analysis: :class:`~feastruct.fea.fea.FiniteElementAnalysis`
:param analysis_cases: List of analysis cases to solve
:type analysis_cases: list[:class:`~feastruct.fea.cases.AnalysisCase`]
:param solver_settings: Settings to use in the solver - if not supplied, the default
settings are adopted
:type solver_settings: :class:`~feastruct.solvers.feasolve.SolverSettings`
"""
super().__init__(analysis, analysis_cases, solver_settings)
# TODO: check that analysis_case results available
[docs] def solve(self):
"""Executes the linear buckling finite element solver and saves the relevant results."""
if self.solver_settings.linear_buckling.time_info:
print('\n-Starting the linear buckling solver...')
# assign the global degree of freedom numbers
if self.solver_settings.linear_static.time_info:
str = '--Assigning the global degree of freedom numbers...'
self.function_timer(str, self.assign_dofs)
else:
self.assign_dofs()
# loop through each analysis case
for (i, analysis_case) in enumerate(self.analysis_cases):
if self.solver_settings.linear_buckling.time_info:
print('\n--Analysis case {0}:'.format(i))
# assemble the global stiffness and geometric stiffness matrices
if self.solver_settings.linear_buckling.time_info:
str = '---Assembling the global stiffness and geometric stiffness matrices...'
(K, K_g) = self.function_timer(
str, self.assemble_stiff_matrix, True, analysis_case)
else:
(K, K_g) = self.assemble_stiff_matrix(geometric=True, analysis_case=analysis_case)
# apply the boundary conditions
K_mod = self.remove_constrained_dofs(K=K, analysis_case=analysis_case)
K_mod_g = self.remove_constrained_dofs(K=K_g, analysis_case=analysis_case)
# solve for the eigenvalues
if self.solver_settings.linear_buckling.time_info:
str = '---Solving for eigenvalues and eigenvectors ({0} modes)...'.format(
self.solver_settings.linear_buckling.num_modes)
(w, v) = self.function_timer(
str, self.solve_eigenvalue, K_mod, -K_mod_g,
self.solver_settings.linear_buckling)
else:
(w, v) = self.solve_eigenvalue(
A=K_mod, M=-K_mod_g, eigen_settings=self.solver_settings.linear_buckling)
self.save_buckling_results(w=w, v=v, analysis_case=analysis_case)