KOKO\Mimi
87 lines
3.4 KiB
C++
87 lines
3.4 KiB
C++
#ifndef FESA_ELEMENTS_HEX8_ELEMENT_H_
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#define FESA_ELEMENTS_HEX8_ELEMENT_H_
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#include <array>
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#include <optional>
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#include "fesa/elements/element.h"
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#include "fesa/materials/isotropic_linear_elastic_material.h"
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#include "fesa/results/solid_result_records.h"
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namespace fesa {
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/// @brief Owns all local quantities from one validated linear or TL trial.
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struct Hex8Response {
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Vector internal_force{24U};
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Matrix material_tangent{24U, 24U};
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Matrix geometric_tangent{24U, 24U};
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Matrix tangent{24U, 24U};
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double strain_energy{0.0};
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std::array<SolidIntegrationPointRow, 8> points{};
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};
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/// @brief Implements full-integration C3D8 linear and TL StVK mechanics.
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/// @note Reference geometry is owned and immutable; no trial is committed.
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class Hex8Element final : public Element {
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public:
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using Coordinates = std::array<std::array<double, 3>, 8>;
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/// @brief Validates identity, isotropic material and whole reference cell.
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/// @param coordinates Reference global coordinates in source node order.
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/// @param density Optional reference mass per volume, positive if present.
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/// @note All inputs are copied; no Domain or section lifetime is required.
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static Result<Hex8Element> Create(
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EntityIndex element_index, ElementDofLayout layout,
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Coordinates coordinates, const LinearElasticMaterial& material,
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std::optional<double> density = std::nullopt,
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SourceLocation location = {});
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const ElementDofLayout& DofLayout() const noexcept override;
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Result<ElementStiffnessContribution> ComputeStiffness() const override;
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Result<ElementResultBundle> Recover(
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const Vector& displacement) const override;
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/// @brief Returns f=K0*u and infinitesimal tensor strain at eight points.
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Result<Hex8Response> EvaluateLinear(const Vector& displacement) const;
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/// @brief Returns one certified StVK trial and its analytic energy Hessian.
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Result<Hex8Response> EvaluateNonlinear(const Vector& displacement) const;
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/// @brief Returns the constant reference consistent mass; density required.
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Result<ElementStiffnessContribution> ComputeMass() const;
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/// @brief Returns immutable positive reference Gauss volume weights.
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/// @note Order is the kernel's fixed eight-point integration order.
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std::array<double, 8> ReferenceWeights() const noexcept;
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private:
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/// @brief Caches shape, reference gradients and positive volume weights.
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struct ReferencePoint {
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std::array<double, 8> shape{};
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std::array<std::array<double, 3>, 8> gradients{};
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std::array<double, 3> natural{};
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std::array<double, 3> position{};
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double weight{0.0};
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};
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/// @brief Constructs an owned candidate before reference validation.
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Hex8Element(EntityIndex element_index, ElementDofLayout layout,
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Coordinates coordinates, double lambda, double mu,
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std::optional<double> density, SourceLocation location);
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/// @brief Evaluates without mutating the cached reference or previous values.
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Result<Hex8Response> Evaluate(const Vector& displacement,
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bool nonlinear) const;
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/// @brief Attaches stable source context to a model failure.
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Status Failure(const char* message) const;
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EntityIndex element_index_;
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ElementDofLayout layout_;
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Coordinates coordinates_;
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double lambda_;
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double mu_;
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std::optional<double> density_;
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SourceLocation location_;
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std::array<ReferencePoint, 8> points_{};
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Matrix stiffness_{24U, 24U};
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};
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} // namespace fesa
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#endif // FESA_ELEMENTS_HEX8_ELEMENT_H_
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