Program Listing for File elastodynamics.h

Return to documentation for file (include/immersx/physics/elastodynamics.h)

// ---------------------------------------------------------------------
//
// Copyright (C) 2026 by Luca Heltai
//
// This file is part of the ImmersX application, based on
// the deal.II library.
//
// The ImmersX application is free software; you can use
// it, redistribute it, and/or modify it under the terms of the Apache-2.0
// License WITH LLVM-exception as published by the Free Software Foundation;
// either version 2.0 of the License, or (at your option) any later version.
// The full text of the license can be found in the LICENSE.md file at the top
// level of the ImmersX distribution.
//
// ---------------------------------------------------------------------

#ifndef immersx_elastodynamics_h
#define immersx_elastodynamics_h

#include <deal.II/base/conditional_ostream.h>
#include <deal.II/base/index_set.h>
#include <deal.II/base/parameter_acceptor.h>
#include <deal.II/base/parsed_convergence_table.h>
#include <deal.II/base/parsed_function.h>
#include <deal.II/base/timer.h>
#include <deal.II/base/utilities.h>

#include <deal.II/distributed/fully_distributed_tria.h>
#include <deal.II/distributed/tria.h>
#include <deal.II/distributed/tria_base.h>

#include <deal.II/dofs/dof_handler.h>
#include <deal.II/dofs/dof_tools.h>

#include <deal.II/fe/fe_q.h>
#include <deal.II/fe/fe_system.h>
#include <deal.II/fe/mapping.h>
#include <deal.II/fe/mapping_q.h>

#include <deal.II/grid/tria.h>

#include <deal.II/lac/affine_constraints.h>
#include <deal.II/lac/dynamic_sparsity_pattern.h>
#include <deal.II/lac/generic_linear_algebra.h>
#include <deal.II/lac/la_parallel_vector.h>
#include <deal.II/lac/solver_control.h>
#include <deal.II/lac/sparsity_tools.h>

#include <deal.II/numerics/data_out.h>

#include <immersx/algebra/linear_algebra.h>
#include <immersx/core/time_parameters.h>

#include <list>
#include <memory>
#include <set>
#include <string>
#include <utility>
#include <variant>
#include <vector>

namespace ImmersX
{
  namespace LA
  {
    using namespace ImmersXLA;
  } // namespace LA


  template <int dim, int spacedim = dim>
  class ElastodynamicsParameters : public dealii::ParameterAcceptor
  {
  private:
    std::unique_ptr<TimeIntervalParameters> owned_time_parameters;
    std::unique_ptr<FixedStepParameters>    owned_fixed_step_parameters;
    std::unique_ptr<IDAParameters>          owned_ida_parameters;

  public:
    explicit ElastodynamicsParameters(
      const std::string      &subsection                   = "/Elastodynamics/",
      TimeIntervalParameters *shared_time_parameters       = nullptr,
      FixedStepParameters    *shared_fixed_step_parameters = nullptr,
      IDAParameters          *shared_ida_parameters        = nullptr);

    std::string  output_directory    = ".";
    std::string  output_name         = "elastodynamics";
    unsigned int fe_degree           = 1;
    unsigned int initial_refinement  = 2;
    unsigned int n_refinement_cycles = 1;

    std::set<dealii::types::boundary_id> dirichlet_ids{0};
    std::set<dealii::types::boundary_id> neumann_ids;
    std::string                          name_of_grid       = "hyper_cube";
    std::string                          arguments_for_grid = "-1: 1: false";
    std::string                          triangulation_type = "distributed";

    double density       = 1.0;
    double lame_mu       = 1.0;
    double lame_lambda   = 1.0;
    double damping_shear = 0.0;
    double damping_bulk  = 0.0;

    TimeIntervalParameters &time_parameters;
    FixedStepParameters &fixed_step_parameters;
    IDAParameters &ida_parameters;

    mutable dealii::ParameterAcceptorProxy<
      dealii::Functions::ParsedFunction<spacedim>>
      body_force;
    mutable dealii::ParameterAcceptorProxy<
      dealii::Functions::ParsedFunction<spacedim>>
      displacement_boundary;
    mutable dealii::ParameterAcceptorProxy<
      dealii::Functions::ParsedFunction<spacedim>>
      neumann_boundary;
    mutable dealii::ParameterAcceptorProxy<
      dealii::Functions::ParsedFunction<spacedim>>
      velocity_boundary;
    mutable dealii::ParameterAcceptorProxy<
      dealii::Functions::ParsedFunction<spacedim>>
      initial_displacement;
    mutable dealii::ParameterAcceptorProxy<
      dealii::Functions::ParsedFunction<spacedim>>
      initial_velocity;

    mutable dealii::ParameterAcceptorProxy<
      dealii::Functions::ParsedFunction<spacedim>>
      exact_solution;

    mutable dealii::ParameterAcceptorProxy<dealii::ReductionControl>
      solver_control;

    mutable dealii::ParsedConvergenceTable convergence_table;
  };


  template <int dim, int spacedim = dim>
  class ElastodynamicsSolver : public dealii::EnableObserverPointer
  {
    static_assert(dim >= 1 && dim <= spacedim && spacedim <= 3,
                  "ElastodynamicsSolver requires 1 <= dim <= spacedim <= 3.");

  public:
    using VectorType = LA::MPI::Vector;
    using MatrixType = LA::MPI::SparseMatrix;

    explicit ElastodynamicsSolver(
      const ElastodynamicsParameters<dim, spacedim> &par);

    void
    make_grid();

    void
    setup_fe();

    void
    setup_system();

    void
    assemble_operators();

    void
    set_initial_conditions();

    void
    refine_global();

    void
    initial_acceleration(VectorType &acceleration) const;

    void
    advance_one_timestep();

    void
    solve();

    void
    output_results() const;

    void
    compute_error() const;

    void
    run();

    void
    set_displacement(const VectorType &new_displacement);

    void
    set_velocity(const VectorType &new_velocity);

    void
    accept_state(const VectorType &new_displacement,
                 const VectorType &new_velocity,
                 double            time,
                 unsigned int      step_number);

    dealii::types::global_dof_index
    n_dofs() const;

    bool
    state_is_finite() const;

    const dealii::parallel::TriangulationBase<dim, spacedim> &
    triangulation() const;

    const dealii::FiniteElement<dim, spacedim> &
    fe() const;

    const dealii::Mapping<dim, spacedim> &
    mapping() const;

    const dealii::DoFHandler<dim, spacedim> &
    dof_handler() const;

    const dealii::AffineConstraints<double> &
    constraints() const;

    const dealii::AffineConstraints<double> &
    velocity_constraints() const;

    const dealii::IndexSet &
    locally_owned_dofs() const;

    const dealii::IndexSet &
    locally_relevant_dofs() const;

    const MatrixType &
    mass_matrix() const;

    const MatrixType &
    stiffness_matrix() const;

    const MatrixType &
    damping_matrix() const;

    const VectorType &
    body_force_vector() const;

    void
    body_force_at_time(double time, VectorType &destination) const;

    void
    update_constraints(double time) const;

    const MatrixType &
    system_matrix() const;

    const VectorType &
    system_rhs() const;

    const VectorType &
    displacement() const;

    const VectorType &
    velocity() const;

    double
    current_time() const;

    double
    time_step() const;

    unsigned int
    time_step_number() const;

  private:
    using DistributedTriangulation =
      dealii::parallel::distributed::Triangulation<dim, spacedim>;
    using FullyDistributedTriangulation =
      dealii::parallel::fullydistributed::Triangulation<dim, spacedim>;
    using TriangulationVariant =
      std::variant<DistributedTriangulation, FullyDistributedTriangulation>;

    static TriangulationVariant
    make_triangulation_storage(MPI_Comm mpi_communicator);

    bool
    uses_fully_distributed_triangulation() const;

    void
    assemble_body_force(double time);

    void
    add_initial_acceleration_constraint_rhs(VectorType &rhs) const;

    void
    assemble_backward_euler_system(const VectorType &previous_displacement,
                                   const VectorType &previous_velocity,
                                   double            dt);

    void
    advance_one_timestep(double dt);

    void
    solve_backward_euler_system();

    void
    update_locally_relevant_state();

    void
    run_time_integration();

    static void
    copy_constraints(const dealii::AffineConstraints<double> &source,
                     dealii::AffineConstraints<double>       &target,
                     dealii::types::global_dof_index          shift);

    const ElastodynamicsParameters<dim, spacedim> &par;

    MPI_Comm                    mpi_communicator;
    dealii::ConditionalOStream  pcout;
    mutable dealii::TimerOutput computing_timer;

    TriangulationVariant                                  triangulation_storage;
    dealii::parallel::TriangulationBase<dim, spacedim>   *tria;
    std::unique_ptr<dealii::FiniteElement<dim, spacedim>> fe_storage;
    std::unique_ptr<dealii::Quadrature<dim>>              quadrature;
    std::unique_ptr<dealii::Mapping<dim, spacedim>>       mapping_storage;
    dealii::DoFHandler<dim, spacedim>                     dh;

    dealii::IndexSet                          owned_dofs;
    dealii::IndexSet                          relevant_dofs;
    dealii::IndexSet                          combined_owned_dofs;
    dealii::IndexSet                          combined_relevant_dofs;
    mutable dealii::AffineConstraints<double> displacement_constraints_storage;
    mutable dealii::AffineConstraints<double> velocity_constraints_storage;
    mutable dealii::AffineConstraints<double> combined_constraints_storage;

    MatrixType mass_matrix_storage;
    MatrixType stiffness_matrix_storage;
    MatrixType damping_matrix_storage;
    MatrixType system_matrix_storage;

    VectorType body_force_storage;
    VectorType displacement_storage;
    VectorType velocity_storage;
    VectorType locally_relevant_displacement;
    VectorType locally_relevant_velocity;
    VectorType system_rhs_storage;

    mutable std::vector<std::pair<double, std::string>> cycles_and_solutions;

    double       current_time_storage     = 0.0;
    double       current_time_step        = 0.0;
    unsigned int time_step_number_storage = 0;
    unsigned int refinement_cycle_storage = 0;
  };

} // namespace ImmersX

#endif // immersx_elastodynamics_h