Connect MITC4 drilling evidence across analysis procedures

include/fesa/elements/element.h

@@ -1,11 +1,14 @@
 #ifndef FESA_ELEMENTS_ELEMENT_H_
 #define FESA_ELEMENTS_ELEMENT_H_
 
+#include <array>
+#include <optional>
 #include <variant>
 #include <vector>
 
 #include "fesa/core/status.h"
 #include "fesa/elements/element_dof_layout.h"
+#include "fesa/elements/mitc4_drilling_mode.h"
 #include "fesa/math/matrix.h"
 #include "fesa/math/vector.h"
 #include "fesa/results/result_records.h"
@@ -30,6 +33,8 @@ struct BeamElementResultRows {
 struct ShellElementResultRows {
   std::vector<ShellResultRow> rows;
   double physical_strain_energy{0.0};
+  std::optional<Mitc4DrillingMode> drilling_mode;
+  std::array<double, 3> drilling_moment{};
 };
 
 /// @brief Selects the physical recovery shape of one runtime element.

include/fesa/elements/element_capabilities.h

@@ -178,6 +178,8 @@ class ShellReferenceElement : public Element {
   virtual Result<Mitc4Stiffness> Stiffness() const = 0;
   /// @copydoc Mitc4Shell::Mass
   virtual Result<Mitc4Mass> Mass(double density) const = 0;
+  /// @brief Returns the actual immutable reference-kernel drilling formulation.
+  virtual Mitc4DrillingMode DrillingMode() const noexcept = 0;
 };
 
 /// @brief Borrows the same linear MITC4 kernel for stiffness and recovery.
@@ -190,6 +192,7 @@ class Mitc4ReferenceAdapter final : public ShellReferenceElement {
   Result<ElementResultBundle> Recover(const Vector& u) const override;
   Result<Mitc4Stiffness> Stiffness() const override;
   Result<Mitc4Mass> Mass(double density) const override;
+  Mitc4DrillingMode DrillingMode() const noexcept override;
 
  private:
   const Mitc4Shell& kernel_;