feat: adopt lumped mass and reduced-coordinate shell HHT

Integrate Hex8 mass verification and fixed-null-basis shell dynamics with numerical and physics handoff evidence. Preserve interrupted reference and full-validation status; full integration validation is deferred until after performance optimization.
2026-10-13 16:57:19 +09:00
parent ede137c6b4
commit eaa5cbeb21
110 changed files with 15274 additions and 971 deletions
@@ -64,7 +64,9 @@ class Hex8Element final : public Element {
  /// @note Failure preserves immutable reference data and all caller state.
  Result<Hex8HighLowResponse> EvaluateNonlinearHighLow(
      const Vector& high, const Vector& low) const;
-  /// @brief Returns the constant reference consistent mass; density required.
+  /// @brief Returns the constant reference row-sum lumped mass; density required.
+  /// @note Each diagonal entry is the row sum of the full 24-by-24 reference
+  /// consistent mass before any constraint reduction.
  Result<ElementStiffnessContribution> ComputeMass() const;
  /// @brief Returns immutable positive reference Gauss volume weights.
  /// @note Order is the kernel's fixed eight-point integration order.