feat: add thermal semantic domain model

include/fesa/model/domain.h

@@ -183,6 +183,30 @@ class Domain {
   const DomainCollectionView<LinearElasticMaterial>& LinearElasticMaterials()
       const noexcept;
 
+  /// @brief Returns thermal materials in stable thermal declaration order.
+  const DomainCollectionView<IsotropicThermalMaterial>& ThermalMaterials()
+      const noexcept;
+
+  /// @brief Returns DS4 definitions in stable thermal declaration order.
+  const DomainCollectionView<Ds4ThermalDefinition>& ThermalElements()
+      const noexcept;
+
+  /// @brief Returns centered thermal shell assignments in declaration order.
+  const std::vector<ThermalShellSectionDefinition>& ThermalSections()
+      const noexcept;
+
+  /// @brief Returns resolved initial temperatures in source order.
+  const std::vector<ThermalInitialConditionDefinition>&
+  ThermalInitialConditions() const noexcept;
+
+  /// @brief Returns model-level thermal boundary definitions in source order.
+  const std::vector<ThermalBoundaryConditionDefinition>&
+  ThermalModelBoundaries() const noexcept;
+
+  /// @brief Returns the sole thermal step, or null when the model is
+  /// structural.
+  const ThermalStepDefinition* ThermalStep() const noexcept;
+
   /// @brief Returns all properties in stable Domain index order.
   const DomainCollectionView<ElementProperty>& Properties() const noexcept;
 
@@ -243,6 +267,8 @@ class Domain {
   DomainCollectionView<ShellSection> shell_sections_view_;
   DomainCollectionView<Material> materials_view_;
   DomainCollectionView<LinearElasticMaterial> linear_materials_view_;
+  DomainCollectionView<IsotropicThermalMaterial> thermal_materials_view_;
+  DomainCollectionView<Ds4ThermalDefinition> thermal_elements_view_;
   DomainCollectionView<StepDefinition> steps_view_;
 };
 

include/fesa/model/model_types.h

@@ -12,9 +12,11 @@
 
 #include "fesa/core/diagnostic.h"
 #include "fesa/core/source_identity.h"
+#include "fesa/elements/ds4_thermal.h"
 #include "fesa/elements/euler_beam_3d.h"
 #include "fesa/elements/mitc4_shell.h"
 #include "fesa/materials/isotropic_linear_elastic_material.h"
+#include "fesa/materials/isotropic_thermal_material.h"
 #include "fesa/properties/general_beam_section.h"
 #include "fesa/properties/shell_section.h"
 
@@ -226,6 +228,89 @@ struct DynamicStepDefinition {
   std::vector<NodalLoad> loads;
 };
 
+/// @brief Stores homogeneous isotropic thermal material source data.
+struct ThermalMaterialDefinition {
+  SourceEntityId source_id;
+  std::string name;
+  double conductivity;
+  double density;
+  double specific_heat;
+  SourceLocation location;
+};
+
+/// @brief Stores one centered homogeneous thermal shell assignment.
+struct ThermalShellSectionDefinition {
+  SourceEntityId source_id;
+  std::string name;
+  double thickness;
+  EntityIndex material_index;
+  SourceLocation location;
+};
+
+/// @brief Stores one DS4 definition before Domain ownership.
+struct Ds4ThermalElementDefinition {
+  SourceEntityId source_id;
+  std::array<EntityIndex, 4> node_indices;
+  EntityIndex section_index;
+  SourceLocation location;
+};
+
+/// @brief Stores one resolved initial temperature target at five stations.
+struct ThermalInitialConditionDefinition {
+  ThermalInitialConditionDefinition(EntityIndex target_node, double value,
+                                    SourceLocation source_location)
+      : node_index{target_node},
+        station_values{{value, value, value, value, value}},
+        location{std::move(source_location)} {}
+
+  EntityIndex node_index;
+  std::array<double, 5> station_values;
+  SourceLocation location;
+};
+
+/// @brief Stores one prescribed thermal source DOF value.
+struct ThermalBoundaryConditionDefinition {
+  EntityIndex node_index;
+  int dof;
+  double value;
+  SourceLocation location;
+};
+
+/// @brief Stores one signed inward CFlux source contribution.
+struct ThermalFluxLoadDefinition {
+  EntityIndex node_index;
+  int dof;
+  double power;
+  SourceLocation location;
+  std::size_t source_order{0U};
+};
+
+/// @brief Stores uncoupled transient heat-step controls without a time grid.
+struct ThermalStepDefinition {
+  std::string name;
+  double nominal_increment;
+  double time_period;
+  std::uint32_t maximum_increments{100U};
+  bool nlgeom{false};
+  std::vector<ThermalBoundaryConditionDefinition> boundaries;
+  std::vector<ThermalFluxLoadDefinition> loads;
+  SourceLocation location;
+
+  /// @brief Returns thermal boundaries in stable source order.
+  const std::vector<ThermalBoundaryConditionDefinition>& Boundaries() const
+      noexcept {
+    return boundaries;
+  }
+
+  /// @brief Returns additive thermal fluxes in stable source order.
+  const std::vector<ThermalFluxLoadDefinition>& Loads() const noexcept {
+    return loads;
+  }
+
+  static constexpr std::array<double, 5> kStationZeta{
+      {-1.0, -0.5, 0.0, 0.5, 1.0}};
+};
+
 /// @brief Stores a stable resolved node-set membership list.
 struct NodeSet {
   std::string name;
@@ -278,8 +363,11 @@ struct ModelDefinition {
   std::vector<EulerBeam3DDefinition> elements;
   std::vector<Mitc4ShellDefinition> shell_elements;
   std::vector<LinearElasticMaterial> materials;
+  std::vector<ThermalMaterialDefinition> thermal_materials;
   std::vector<GeneralBeamSection> sections;
   std::vector<ShellSection> shell_sections;
+  std::vector<ThermalShellSectionDefinition> thermal_sections;
+  std::vector<Ds4ThermalElementDefinition> thermal_elements;
   std::vector<ShellNodeInitialFrame> shell_node_initial_frames;
   std::vector<NodeSet> node_sets;
   std::vector<ElementSet> element_sets;
@@ -290,6 +378,9 @@ struct ModelDefinition {
   std::vector<MaterialDensityDefinition> densities;
   std::optional<FrequencyStepDefinition> frequency_step;
   std::optional<DynamicStepDefinition> dynamic_step;
+  std::vector<ThermalInitialConditionDefinition> thermal_initial_conditions;
+  std::vector<ThermalBoundaryConditionDefinition> thermal_model_boundaries;
+  std::optional<ThermalStepDefinition> thermal_step;
   std::vector<Diagnostic> warnings;
 };