Beam problem object. More...

Inheritance diagram for ElasticBeamProblem:

Public Member Functions
	ElasticBeamProblem (const unsigned &n_elem, const double &length)
	Constructor for elastic beam problem. More...

void	parameter_study ()
	Conduct a parameter study. More...

OneDLagrangianMesh< HermiteBeamElement > *	mesh_pt ()
	Return pointer to the mesh. More...

void	actions_after_newton_solve ()
	No actions need to be performed after a solve. More...

void	actions_before_newton_solve ()
	No actions need to be performed before a solve. More...

Public Member Functions inherited from oomph::Problem
virtual void	debug_hook_fct (const unsigned &i)

void	set_analytic_dparameter (double *const &parameter_pt)

void	unset_analytic_dparameter (double *const &parameter_pt)

bool	is_dparameter_calculated_analytically (double *const &parameter_pt)

void	set_analytic_hessian_products ()

void	unset_analytic_hessian_products ()

bool	are_hessian_products_calculated_analytically ()

void	set_pinned_values_to_zero ()

bool	distributed () const

virtual void	actions_before_adapt ()

virtual void	actions_after_adapt ()
	Actions that are to be performed after a mesh adaptation. More...

OomphCommunicator *	communicator_pt ()
	access function to the oomph-lib communicator More...

const OomphCommunicator *	communicator_pt () const
	access function to the oomph-lib communicator, const version More...

	Problem ()

	Problem (const Problem &dummy)=delete
	Broken copy constructor. More...

void	operator= (const Problem &)=delete
	Broken assignment operator. More...

virtual	~Problem ()
	Virtual destructor to clean up memory. More...

Mesh *&	mesh_pt ()
	Return a pointer to the global mesh. More...

Mesh *const &	mesh_pt () const
	Return a pointer to the global mesh (const version) More...

Mesh *&	mesh_pt (const unsigned &imesh)

Mesh *const &	mesh_pt (const unsigned &imesh) const
	Return a pointer to the i-th submesh (const version) More...

unsigned	nsub_mesh () const
	Return number of submeshes. More...

unsigned	add_sub_mesh (Mesh *const &mesh_pt)

void	flush_sub_meshes ()

void	build_global_mesh ()

void	rebuild_global_mesh ()

LinearSolver *&	linear_solver_pt ()
	Return a pointer to the linear solver object. More...

LinearSolver *const &	linear_solver_pt () const
	Return a pointer to the linear solver object (const version) More...

LinearSolver *&	mass_matrix_solver_for_explicit_timestepper_pt ()

LinearSolver *	mass_matrix_solver_for_explicit_timestepper_pt () const

EigenSolver *&	eigen_solver_pt ()
	Return a pointer to the eigen solver object. More...

EigenSolver *const &	eigen_solver_pt () const
	Return a pointer to the eigen solver object (const version) More...

Time *&	time_pt ()
	Return a pointer to the global time object. More...

Time *	time_pt () const
	Return a pointer to the global time object (const version). More...

double &	time ()
	Return the current value of continuous time. More...

double	time () const
	Return the current value of continuous time (const version) More...

TimeStepper *&	time_stepper_pt ()

const TimeStepper *	time_stepper_pt () const

TimeStepper *&	time_stepper_pt (const unsigned &i)
	Return a pointer to the i-th timestepper. More...

ExplicitTimeStepper *&	explicit_time_stepper_pt ()
	Return a pointer to the explicit timestepper. More...

unsigned long	set_timestepper_for_all_data (TimeStepper *const &time_stepper_pt, const bool &preserve_existing_data=false)

virtual void	shift_time_values ()
	Shift all values along to prepare for next timestep. More...

AssemblyHandler *&	assembly_handler_pt ()
	Return a pointer to the assembly handler object. More...

AssemblyHandler *const &	assembly_handler_pt () const
	Return a pointer to the assembly handler object (const version) More...

double &	minimum_dt ()
	Access function to min timestep in adaptive timestepping. More...

double &	maximum_dt ()
	Access function to max timestep in adaptive timestepping. More...

unsigned &	max_newton_iterations ()
	Access function to max Newton iterations before giving up. More...

void	problem_is_nonlinear (const bool &prob_lin)
	Access function to Problem_is_nonlinear. More...

double &	max_residuals ()

bool &	time_adaptive_newton_crash_on_solve_fail ()
	Access function for Time_adaptive_newton_crash_on_solve_fail. More...

double &	newton_solver_tolerance ()

void	add_time_stepper_pt (TimeStepper *const &time_stepper_pt)

void	set_explicit_time_stepper_pt (ExplicitTimeStepper *const &explicit_time_stepper_pt)

void	initialise_dt (const double &dt)

void	initialise_dt (const Vector< double > &dt)

Data *&	global_data_pt (const unsigned &i)
	Return a pointer to the the i-th global data object. More...

void	add_global_data (Data *const &global_data_pt)

void	flush_global_data ()

LinearAlgebraDistribution *const &	dof_distribution_pt () const
	Return the pointer to the dof distribution (read-only) More...

unsigned long	ndof () const
	Return the number of dofs. More...

unsigned	ntime_stepper () const
	Return the number of time steppers. More...

unsigned	nglobal_data () const
	Return the number of global data values. More...

unsigned	self_test ()
	Self-test: Check meshes and global data. Return 0 for OK. More...

void	enable_store_local_dof_pt_in_elements ()

void	disable_store_local_dof_pt_in_elements ()

unsigned long	assign_eqn_numbers (const bool &assign_local_eqn_numbers=true)

void	describe_dofs (std::ostream &out= *(oomph_info.stream_pt())) const

void	enable_discontinuous_formulation ()

void	disable_discontinuous_formulation ()

void	get_dofs (DoubleVector &dofs) const

void	get_dofs (const unsigned &t, DoubleVector &dofs) const
	Return vector of the t'th history value of all dofs. More...

void	set_dofs (const DoubleVector &dofs)
	Set the values of the dofs. More...

void	set_dofs (const unsigned &t, DoubleVector &dofs)
	Set the history values of the dofs. More...

void	set_dofs (const unsigned &t, Vector< double * > &dof_pt)

void	add_to_dofs (const double &lambda, const DoubleVector &increment_dofs)
	Add lambda x incremenet_dofs[l] to the l-th dof. More...

double *	global_dof_pt (const unsigned &i)

double &	dof (const unsigned &i)
	i-th dof in the problem More...

double	dof (const unsigned &i) const
	i-th dof in the problem (const version) More...

double *&	dof_pt (const unsigned &i)
	Pointer to i-th dof in the problem. More...

double *	dof_pt (const unsigned &i) const
	Pointer to i-th dof in the problem (const version) More...

virtual void	get_inverse_mass_matrix_times_residuals (DoubleVector &Mres)

virtual void	get_dvaluesdt (DoubleVector &f)

virtual void	get_residuals (DoubleVector &residuals)
	Get the total residuals Vector for the problem. More...

virtual void	get_jacobian (DoubleVector &residuals, DenseDoubleMatrix &jacobian)

virtual void	get_jacobian (DoubleVector &residuals, CRDoubleMatrix &jacobian)

virtual void	get_jacobian (DoubleVector &residuals, CCDoubleMatrix &jacobian)

virtual void	get_jacobian (DoubleVector &residuals, SumOfMatrices &jacobian)

void	get_fd_jacobian (DoubleVector &residuals, DenseMatrix< double > &jacobian)
	Get the full Jacobian by finite differencing. More...

void	get_derivative_wrt_global_parameter (double *const &parameter_pt, DoubleVector &result)

void	get_hessian_vector_products (DoubleVectorWithHaloEntries const &Y, Vector< DoubleVectorWithHaloEntries > const &C, Vector< DoubleVectorWithHaloEntries > &product)

void	solve_eigenproblem (const unsigned &n_eval, Vector< std::complex< double >> &eigenvalue, Vector< DoubleVector > &eigenvector, const bool &steady=true)
	Solve the eigenproblem. More...

void	solve_eigenproblem (const unsigned &n_eval, Vector< std::complex< double >> &eigenvalue, const bool &steady=true)

virtual void	get_eigenproblem_matrices (CRDoubleMatrix &mass_matrix, CRDoubleMatrix &main_matrix, const double &shift=0.0)

void	assign_eigenvector_to_dofs (DoubleVector &eigenvector)
	Assign the eigenvector passed to the function to the dofs. More...

void	add_eigenvector_to_dofs (const double &epsilon, const DoubleVector &eigenvector)

void	store_current_dof_values ()
	Store the current values of the degrees of freedom. More...

void	restore_dof_values ()
	Restore the stored values of the degrees of freedom. More...

void	enable_jacobian_reuse ()

void	disable_jacobian_reuse ()
	Disable recycling of Jacobian in Newton iteration. More...

bool	jacobian_reuse_is_enabled ()
	Is recycling of Jacobian in Newton iteration enabled? More...

bool &	use_predictor_values_as_initial_guess ()

void	newton_solve ()
	Use Newton method to solve the problem. More...

void	enable_globally_convergent_newton_method ()
	enable globally convergent Newton method More...

void	disable_globally_convergent_newton_method ()
	disable globally convergent Newton method More...

void	newton_solve (unsigned const &max_adapt)

void	steady_newton_solve (unsigned const &max_adapt=0)

void	copy (Problem *orig_problem_pt)

virtual Problem *	make_copy ()

virtual void	read (std::ifstream &restart_file, bool &unsteady_restart)

virtual void	read (std::ifstream &restart_file)

virtual void	dump (std::ofstream &dump_file) const

void	dump (const std::string &dump_file_name) const

void	delete_all_external_storage ()

virtual void	symmetrise_eigenfunction_for_adaptive_pitchfork_tracking ()

double *	bifurcation_parameter_pt () const

void	get_bifurcation_eigenfunction (Vector< DoubleVector > &eigenfunction)

void	activate_fold_tracking (double *const &parameter_pt, const bool &block_solve=true)

void	activate_bifurcation_tracking (double *const &parameter_pt, const DoubleVector &eigenvector, const bool &block_solve=true)

void	activate_bifurcation_tracking (double *const &parameter_pt, const DoubleVector &eigenvector, const DoubleVector &normalisation, const bool &block_solve=true)

void	activate_pitchfork_tracking (double *const &parameter_pt, const DoubleVector &symmetry_vector, const bool &block_solve=true)

void	activate_hopf_tracking (double *const &parameter_pt, const bool &block_solve=true)

void	activate_hopf_tracking (double *const &parameter_pt, const double &omega, const DoubleVector &null_real, const DoubleVector &null_imag, const bool &block_solve=true)

void	deactivate_bifurcation_tracking ()

void	reset_assembly_handler_to_default ()
	Reset the system to the standard non-augemented state. More...

double	arc_length_step_solve (double *const &parameter_pt, const double &ds, const unsigned &max_adapt=0)

double	arc_length_step_solve (Data *const &data_pt, const unsigned &data_index, const double &ds, const unsigned &max_adapt=0)

void	reset_arc_length_parameters ()

int &	sign_of_jacobian ()

void	explicit_timestep (const double &dt, const bool &shift_values=true)
	Take an explicit timestep of size dt. More...

void	unsteady_newton_solve (const double &dt)

void	unsteady_newton_solve (const double &dt, const bool &shift_values)

void	unsteady_newton_solve (const double &dt, const unsigned &max_adapt, const bool &first, const bool &shift=true)

double	doubly_adaptive_unsteady_newton_solve (const double &dt, const double &epsilon, const unsigned &max_adapt, const bool &first, const bool &shift=true)

double	doubly_adaptive_unsteady_newton_solve (const double &dt, const double &epsilon, const unsigned &max_adapt, const unsigned &suppress_resolve_after_spatial_adapt_flag, const bool &first, const bool &shift=true)

double	adaptive_unsteady_newton_solve (const double &dt_desired, const double &epsilon)

double	adaptive_unsteady_newton_solve (const double &dt_desired, const double &epsilon, const bool &shift_values)

void	assign_initial_values_impulsive ()

void	assign_initial_values_impulsive (const double &dt)

void	calculate_predictions ()
	Calculate predictions. More...

void	enable_mass_matrix_reuse ()

void	disable_mass_matrix_reuse ()

bool	mass_matrix_reuse_is_enabled ()
	Return whether the mass matrix is being reused. More...

void	refine_uniformly (const Vector< unsigned > &nrefine_for_mesh)

void	refine_uniformly (const Vector< unsigned > &nrefine_for_mesh, DocInfo &doc_info)

void	refine_uniformly_and_prune (const Vector< unsigned > &nrefine_for_mesh)

void	refine_uniformly_and_prune (const Vector< unsigned > &nrefine_for_mesh, DocInfo &doc_info)

void	refine_uniformly (DocInfo &doc_info)

void	refine_uniformly_and_prune (DocInfo &doc_info)

void	refine_uniformly ()

void	refine_uniformly (const unsigned &i_mesh, DocInfo &doc_info)
	Do uniform refinement for submesh i_mesh with documentation. More...

void	refine_uniformly (const unsigned &i_mesh)
	Do uniform refinement for submesh i_mesh without documentation. More...

void	p_refine_uniformly (const Vector< unsigned > &nrefine_for_mesh)

void	p_refine_uniformly (const Vector< unsigned > &nrefine_for_mesh, DocInfo &doc_info)

void	p_refine_uniformly_and_prune (const Vector< unsigned > &nrefine_for_mesh)

void	p_refine_uniformly_and_prune (const Vector< unsigned > &nrefine_for_mesh, DocInfo &doc_info)

void	p_refine_uniformly (DocInfo &doc_info)

void	p_refine_uniformly_and_prune (DocInfo &doc_info)

void	p_refine_uniformly ()

void	p_refine_uniformly (const unsigned &i_mesh, DocInfo &doc_info)
	Do uniform p-refinement for submesh i_mesh with documentation. More...

void	p_refine_uniformly (const unsigned &i_mesh)
	Do uniform p-refinement for submesh i_mesh without documentation. More...

void	refine_selected_elements (const Vector< unsigned > &elements_to_be_refined)

void	refine_selected_elements (const Vector< RefineableElement * > &elements_to_be_refined_pt)

void	refine_selected_elements (const unsigned &i_mesh, const Vector< unsigned > &elements_to_be_refined)

void	refine_selected_elements (const unsigned &i_mesh, const Vector< RefineableElement * > &elements_to_be_refined_pt)

void	refine_selected_elements (const Vector< Vector< unsigned >> &elements_to_be_refined)

void	refine_selected_elements (const Vector< Vector< RefineableElement * >> &elements_to_be_refined_pt)

void	p_refine_selected_elements (const Vector< unsigned > &elements_to_be_refined)

void	p_refine_selected_elements (const Vector< PRefineableElement * > &elements_to_be_refined_pt)

void	p_refine_selected_elements (const unsigned &i_mesh, const Vector< unsigned > &elements_to_be_refined)

void	p_refine_selected_elements (const unsigned &i_mesh, const Vector< PRefineableElement * > &elements_to_be_refined_pt)

void	p_refine_selected_elements (const Vector< Vector< unsigned >> &elements_to_be_refined)

void	p_refine_selected_elements (const Vector< Vector< PRefineableElement * >> &elements_to_be_refined_pt)

unsigned	unrefine_uniformly ()

unsigned	unrefine_uniformly (const unsigned &i_mesh)

void	p_unrefine_uniformly (DocInfo &doc_info)

void	p_unrefine_uniformly (const unsigned &i_mesh, DocInfo &doc_info)
	Do uniform p-unrefinement for submesh i_mesh without documentation. More...

void	adapt (unsigned &n_refined, unsigned &n_unrefined)

void	adapt ()

void	p_adapt (unsigned &n_refined, unsigned &n_unrefined)

void	p_adapt ()

void	adapt_based_on_error_estimates (unsigned &n_refined, unsigned &n_unrefined, Vector< Vector< double >> &elemental_error)

void	adapt_based_on_error_estimates (Vector< Vector< double >> &elemental_error)

void	get_all_error_estimates (Vector< Vector< double >> &elemental_error)

void	doc_errors (DocInfo &doc_info)
	Get max and min error for all elements in submeshes. More...

void	doc_errors ()
	Get max and min error for all elements in submeshes. More...

void	enable_info_in_newton_solve ()

void	disable_info_in_newton_solve ()
	Disable the output of information when in the newton solver. More...

Public Member Functions inherited from oomph::ExplicitTimeSteppableObject
	ExplicitTimeSteppableObject ()
	Empty constructor. More...

	ExplicitTimeSteppableObject (const ExplicitTimeSteppableObject &)=delete
	Broken copy constructor. More...

void	operator= (const ExplicitTimeSteppableObject &)=delete
	Broken assignment operator. More...

virtual	~ExplicitTimeSteppableObject ()
	Empty destructor. More...

virtual void	actions_before_explicit_stage ()

virtual void	actions_after_explicit_stage ()

Private Attributes
Node *	Doc_node_pt
	Pointer to the node whose displacement is documented. More...

double	Length
	Length of domain (in terms of the Lagrangian coordinates) More...

GeomObject *	Undef_beam_pt
	Pointer to geometric object that represents the beam's undeformed shape. More...

Additional Inherited Members
Public Types inherited from oomph::Problem
typedef void(*	SpatialErrorEstimatorFctPt) (Mesh *&mesh_pt, Vector< double > &elemental_error)
	Function pointer for spatial error estimator. More...

typedef void(*	SpatialErrorEstimatorWithDocFctPt) (Mesh *&mesh_pt, Vector< double > &elemental_error, DocInfo &doc_info)
	Function pointer for spatial error estimator with doc. More...

Public Attributes inherited from oomph::Problem
bool	Shut_up_in_newton_solve

Static Public Attributes inherited from oomph::Problem
static bool	Suppress_warning_about_actions_before_read_unstructured_meshes

Protected Types inherited from oomph::Problem
enum	Assembly_method { Perform_assembly_using_vectors_of_pairs , Perform_assembly_using_two_vectors , Perform_assembly_using_maps , Perform_assembly_using_lists , Perform_assembly_using_two_arrays }
	Enumerated flags to determine which sparse assembly method is used. More...

Protected Member Functions inherited from oomph::Problem
unsigned	setup_element_count_per_dof ()

virtual void	sparse_assemble_row_or_column_compressed (Vector< int * > &column_or_row_index, Vector< int * > &row_or_column_start, Vector< double * > &value, Vector< unsigned > &nnz, Vector< double * > &residual, bool compressed_row_flag)

virtual void	actions_before_newton_convergence_check ()

virtual void	actions_before_newton_step ()

virtual void	actions_after_newton_step ()

virtual void	actions_before_implicit_timestep ()

virtual void	actions_after_implicit_timestep ()

virtual void	actions_after_implicit_timestep_and_error_estimation ()

virtual void	actions_before_explicit_timestep ()
	Actions that should be performed before each explicit time step. More...

virtual void	actions_after_explicit_timestep ()
	Actions that should be performed after each explicit time step. More...

virtual void	actions_before_read_unstructured_meshes ()

virtual void	actions_after_read_unstructured_meshes ()

virtual void	actions_after_change_in_global_parameter (double *const &parameter_pt)

virtual void	actions_after_change_in_bifurcation_parameter ()

virtual void	actions_after_parameter_increase (double *const &parameter_pt)

double &	dof_derivative (const unsigned &i)

double &	dof_current (const unsigned &i)

virtual void	set_initial_condition ()

virtual double	global_temporal_error_norm ()

unsigned	newton_solve_continuation (double *const &parameter_pt)

unsigned	newton_solve_continuation (double *const &parameter_pt, DoubleVector &z)

void	calculate_continuation_derivatives (double *const &parameter_pt)

void	calculate_continuation_derivatives (const DoubleVector &z)

void	calculate_continuation_derivatives_fd (double *const &parameter_pt)

bool	does_pointer_correspond_to_problem_data (double *const &parameter_pt)

void	set_consistent_pinned_values_for_continuation ()

Protected Attributes inherited from oomph::Problem
Vector< Problem * >	Copy_of_problem_pt

std::map< double *, bool >	Calculate_dparameter_analytic

bool	Calculate_hessian_products_analytic

LinearAlgebraDistribution *	Dof_distribution_pt

Vector< double * >	Dof_pt
	Vector of pointers to dofs. More...

DoubleVectorWithHaloEntries	Element_count_per_dof

double	Relaxation_factor

double	Newton_solver_tolerance

unsigned	Max_newton_iterations
	Maximum number of Newton iterations. More...

unsigned	Nnewton_iter_taken

Vector< double >	Max_res
	Maximum residuals at start and after each newton iteration. More...

double	Max_residuals

bool	Time_adaptive_newton_crash_on_solve_fail

bool	Jacobian_reuse_is_enabled
	Is re-use of Jacobian in Newton iteration enabled? Default: false. More...

bool	Jacobian_has_been_computed

bool	Problem_is_nonlinear

bool	Pause_at_end_of_sparse_assembly

bool	Doc_time_in_distribute

unsigned	Sparse_assembly_method

unsigned	Sparse_assemble_with_arrays_initial_allocation

unsigned	Sparse_assemble_with_arrays_allocation_increment

Vector< Vector< unsigned > >	Sparse_assemble_with_arrays_previous_allocation

double	Numerical_zero_for_sparse_assembly

double	FD_step_used_in_get_hessian_vector_products

bool	Mass_matrix_reuse_is_enabled

bool	Mass_matrix_has_been_computed

bool	Discontinuous_element_formulation

double	Minimum_dt
	Minimum desired dt: if dt falls below this value, exit. More...

double	Maximum_dt
	Maximum desired dt. More...

double	DTSF_max_increase

double	DTSF_min_decrease

double	Minimum_dt_but_still_proceed

bool	Scale_arc_length
	Boolean to control whether arc-length should be scaled. More...

double	Desired_proportion_of_arc_length
	Proportion of the arc-length to taken by the parameter. More...

double	Theta_squared

int	Sign_of_jacobian
	Storage for the sign of the global Jacobian. More...

double	Continuation_direction

double	Parameter_derivative
	Storage for the derivative of the global parameter wrt arc-length. More...

double	Parameter_current
	Storage for the present value of the global parameter. More...

bool	Use_continuation_timestepper
	Boolean to control original or new storage of dof stuff. More...

unsigned	Dof_derivative_offset

unsigned	Dof_current_offset

Vector< double >	Dof_derivative
	Storage for the derivative of the problem variables wrt arc-length. More...

Vector< double >	Dof_current
	Storage for the present values of the variables. More...

double	Ds_current
	Storage for the current step value. More...

unsigned	Desired_newton_iterations_ds

double	Minimum_ds
	Minimum desired value of arc-length. More...

bool	Bifurcation_detection
	Boolean to control bifurcation detection via determinant of Jacobian. More...

bool	Bisect_to_find_bifurcation
	Boolean to control wheter bisection is used to located bifurcation. More...

bool	First_jacobian_sign_change
	Boolean to indicate whether a sign change has occured in the Jacobian. More...

bool	Arc_length_step_taken
	Boolean to indicate whether an arc-length step has been taken. More...

bool	Use_finite_differences_for_continuation_derivatives

OomphCommunicator *	Communicator_pt
	The communicator for this problem. More...

bool	Always_take_one_newton_step

double	Timestep_reduction_factor_after_nonconvergence

bool	Keep_temporal_error_below_tolerance

Static Protected Attributes inherited from oomph::Problem
static ContinuationStorageScheme	Continuation_time_stepper
	Storage for the single static continuation timestorage object. More...

Detailed Description

Beam problem object.

Constructor & Destructor Documentation

◆ ElasticBeamProblem()

ElasticBeamProblem::ElasticBeamProblem	(	const unsigned &	n_elem,
		const double &	length
	)

Constructor for elastic beam problem.

Constructor: The arguments are the number of elements, the length of domain

                                                              : Length(length)
 {
  // Set the undeformed beam to be a straight line at y=0
  Undef_beam_pt=new StraightLine(0.0); 
  
  // Create the (Lagrangian!) mesh, using the geometric object
  // Undef_beam_pt to specify the initial (Eulerian) position of the
  // nodes.
  Problem::mesh_pt() = 
   new OneDLagrangianMesh<HermiteBeamElement>(n_elem,length,Undef_beam_pt);
  
  // Set the boundary conditions: Each end of the beam is fixed in space
  // Loop over the boundaries (ends of the beam)
  for(unsigned b=0;b<2;b++)
   {
    // Pin displacements in both x and y directions
    // [Note: The mesh_pt() function has been overloaded
    //  to return a pointer to the actual mesh, rather than
    //  a pointer to the Mesh base class. The current mesh is derived
    //  from the SolidMesh class. In such meshes, all access functions
    //  to the nodes, such as boundary_node_pt(...), are overloaded
    //  to return pointers to SolidNodes (whose position can be
    //  pinned) rather than "normal" Nodes.]
    mesh_pt()->boundary_node_pt(b,0)->pin_position(0); 
    mesh_pt()->boundary_node_pt(b,0)->pin_position(1); 
   }
  
  //Find number of elements in the mesh
  unsigned n_element = mesh_pt()->nelement();
  
  //Loop over the elements to set physical parameters etc.
  for(unsigned e=0;e<n_element;e++)
   {
    // Upcast to the specific element type
    HermiteBeamElement *elem_pt = 
     dynamic_cast<HermiteBeamElement*>(mesh_pt()->element_pt(e));
    
    // Set physical parameters for each element:
    elem_pt->sigma0_pt() = &Global_Physical_Variables::Sigma0;
    elem_pt->h_pt() = &Global_Physical_Variables::H;
  
    // Set the load Vector for each element
    elem_pt->load_vector_fct_pt() = &Global_Physical_Variables::load;
  
    // Set the undeformed shape for each element
    elem_pt->undeformed_beam_pt() = Undef_beam_pt;
   } // end of loop over elements
  
  // Choose node at which displacement is documented (halfway along -- provided
  // we have an odd number of nodes; complain if this is not the
  // case because the comparison with the exact solution will be wrong 
  // otherwise!)
  unsigned n_nod=mesh_pt()->nnode();
  if (n_nod%2!=1)
   {
    cout << "Warning: Even number of nodes " << n_nod << std::endl;
    cout << "Comparison with exact solution will be misleading..." << std::endl;
   }
  Doc_node_pt=mesh_pt()->node_pt((n_nod+1)/2-1);
  
  // Assign the global and local equation numbers
  cout << "# of dofs " << assign_eqn_numbers() << std::endl;
  
 } // end of constructor

References oomph::Problem::assign_eqn_numbers(), b, Doc_node_pt, e(), Global_Physical_Variables::H, oomph::KirchhoffLoveBeamEquations::h_pt(), Global_Physical_Variables::load(), oomph::KirchhoffLoveBeamEquations::load_vector_fct_pt, mesh_pt(), Global_Physical_Variables::Sigma0, oomph::KirchhoffLoveBeamEquations::sigma0_pt(), Undef_beam_pt, and oomph::KirchhoffLoveBeamEquations::undeformed_beam_pt().

Member Function Documentation

◆ actions_after_newton_solve()

void ElasticBeamProblem::actions_after_newton_solve ( )

inlinevirtual

No actions need to be performed after a solve.

Reimplemented from oomph::Problem.

80 {}

◆ actions_before_newton_solve()

void ElasticBeamProblem::actions_before_newton_solve ( )

inlinevirtual

No actions need to be performed before a solve.

Reimplemented from oomph::Problem.

83 {}

◆ mesh_pt()

OneDLagrangianMesh<HermiteBeamElement>* ElasticBeamProblem::mesh_pt ( )

inline

Return pointer to the mesh.

76 {return dynamic_cast<OneDLagrangianMesh<HermiteBeamElement>*>

77 (Problem::mesh_pt());}

Referenced by ElasticBeamProblem(), and parameter_study().

◆ parameter_study()

void ElasticBeamProblem::parameter_study ( )

Conduct a parameter study.

Solver loop to perform parameter study.

 {
  // Over-ride the default maximum value for the residuals
  Problem::Max_residuals = 1.0e10;
  
  // Set the increments in control parameters
  double pext_increment = 0.001;
  
  // Set initial values for control parameters 
  Global_Physical_Variables::P_ext = 0.0 - pext_increment;
  
  // Create label for output
  DocInfo doc_info;
  
  // Set output directory -- this function checks if the output
  // directory exists and issues a warning if it doesn't.
  doc_info.set_directory("RESLT");
  
  // Open a trace file
  ofstream trace("RESLT/trace_beam.dat");
  
  // Write a header for the trace file
  trace << 
   "VARIABLES=\"p_e_x_t\",\"d\"" << 
   ", \"p_e_x_t_(_e_x_a_c_t_)\"" << std::endl;
  
  // Output file stream used for writing results
  ofstream file;
  // String used for the filename
  char filename[100]; 
  
  // Loop over parameter increments
  unsigned nstep=10;
  for(unsigned i=1;i<=nstep;i++)
   {
    // Increment pressure
    Global_Physical_Variables::P_ext += pext_increment;
    
    // Solve the system
    newton_solve();
     
    // Calculate exact solution for `string under tension' (applicable for
    // small wall thickness and pinned ends)
  
    // The tangent of the angle beta
    double tanbeta =-2.0*Doc_node_pt->x(1)/Length;
  
    double exact_pressure = 0.0;
    //If the beam has deformed, calculate the pressure required
    if(tanbeta!=0)
     {
       
       //Calculate the opening angle alpha
       double alpha = 2.0*atan(2.0*tanbeta/(1.0-tanbeta*tanbeta));
  
       // Jump back onto the main branch if alpha>180 degrees
       if (alpha<0) alpha+=2.0*MathematicalConstants::Pi;
  
      // Green strain:
      double gamma=0.5*(0.25*alpha*alpha/(sin(0.5*alpha)*sin(0.5*alpha))-1.0);
  
      //Calculate the exact pressure
      exact_pressure=Global_Physical_Variables::H*
       (Global_Physical_Variables::Sigma0+gamma)*alpha/Length;
     } 
    
    // Document the solution
    sprintf(filename,"RESLT/beam%i.dat",i);
    file.open(filename);
    mesh_pt()->output(file,5);
    file.close();
    
    // Write trace file: Pressure, displacement and exact solution
    // (for string under tension)
    trace << Global_Physical_Variables::P_ext  << " " 
          << abs(Doc_node_pt->x(1))
          << " " << exact_pressure 
          << std::endl;
   }
  
 } // end of parameter study

References abs(), alpha, Eigen::bfloat16_impl::atan(), Doc_node_pt, MergeRestartFiles::filename, mathsFunc::gamma(), Global_Physical_Variables::H, i, Length, mesh_pt(), oomph::Problem::newton_solve(), Global_Physical_Variables::P_ext, BiharmonicTestFunctions2::Pi, oomph::DocInfo::set_directory(), Global_Physical_Variables::Sigma0, sin(), and oomph::Node::x().

Member Data Documentation

◆ Doc_node_pt

Node* ElasticBeamProblem::Doc_node_pt

private

Pointer to the node whose displacement is documented.

Referenced by ElasticBeamProblem(), and parameter_study().

◆ Length

double ElasticBeamProblem::Length

private

Length of domain (in terms of the Lagrangian coordinates)

Referenced by parameter_study().

◆ Undef_beam_pt

GeomObject* ElasticBeamProblem::Undef_beam_pt

private

Pointer to geometric object that represents the beam's undeformed shape.

Referenced by ElasticBeamProblem().

The documentation for this class was generated from the following file:

tensioned_string.cc

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ElasticBeamProblem()

Member Function Documentation

◆ actions_after_newton_solve()

◆ actions_before_newton_solve()

◆ mesh_pt()

◆ parameter_study()

Member Data Documentation

◆ Doc_node_pt

◆ Length

◆ Undef_beam_pt