feat: add mitc4 covariant strain tying

This commit is contained in:
NINI
2026-05-04 22:02:25 +09:00
parent fa492f994d
commit d550e13e77
5 changed files with 369 additions and 6 deletions
+188
View File
@@ -1301,6 +1301,64 @@ struct MITC4IntegrationBasis {
}
};
using MITC4ElementDofVector = std::array<Real, 24>;
using MITC4StrainVector = std::array<Real, 6>;
using MITC4StrainRow = std::array<Real, 24>;
enum class MITC4StrainComponent {
Eps11 = 0,
Eps22 = 1,
Eps33 = 2,
Gamma23 = 3,
Gamma13 = 4,
Gamma12 = 5
};
inline std::size_t strainComponentIndex(MITC4StrainComponent component) {
return static_cast<std::size_t>(component);
}
inline std::array<std::string, 6> mitc4StrainComponentLabels() {
return {"eps11", "eps22", "eps33", "gamma23", "gamma13", "gamma12"};
}
struct MITC4LocalRotations {
Real alpha = 0.0;
Real beta = 0.0;
Real gamma = 0.0;
};
struct MITC4DisplacementDerivatives {
ShapeData shape;
Vec3 displacement;
Vec3 du_dxi;
Vec3 du_deta;
Vec3 du_dzeta;
std::vector<Diagnostic> diagnostics;
bool ok() const {
return !hasError(diagnostics);
}
};
struct MITC4StrainEvaluation {
MITC4StrainVector values{};
std::vector<Diagnostic> diagnostics;
bool ok() const {
return !hasError(diagnostics);
}
};
struct MITC4StrainRows {
std::array<MITC4StrainRow, 6> rows{};
std::vector<Diagnostic> diagnostics;
bool ok() const {
return !hasError(diagnostics);
}
};
inline Vec3 globalEX() {
return {1.0, 0.0, 0.0};
}
@@ -1317,6 +1375,10 @@ inline Diagnostic mitc4Diagnostic(std::string code, std::string message) {
return makeDiagnostic(Severity::Error, std::move(code), std::move(message), "mitc4", "<element>", 0);
}
inline void appendDiagnostics(std::vector<Diagnostic>& target, const std::vector<Diagnostic>& source) {
target.insert(target.end(), source.begin(), source.end());
}
inline MITC4MidsurfaceDerivatives mitc4MidsurfaceDerivatives(const std::array<Vec3, 4>& coordinates, Real xi, Real eta) {
MITC4MidsurfaceDerivatives result;
result.shape = shapeFunctions(xi, eta);
@@ -1436,6 +1498,132 @@ inline MITC4IntegrationBasis computeMITC4IntegrationBasis(const MITC4Geometry& g
return result;
}
inline Vec3 mitc4NodalTranslation(const MITC4ElementDofVector& values, std::size_t node) {
const std::size_t base = 6 * node;
return {values[base + 0], values[base + 1], values[base + 2]};
}
inline Vec3 mitc4NodalRotation(const MITC4ElementDofVector& values, std::size_t node) {
const std::size_t base = 6 * node;
return {values[base + 3], values[base + 4], values[base + 5]};
}
inline MITC4LocalRotations mitc4LocalRotations(const MITC4DirectorFrame& frame, const Vec3& global_rotation) {
return {dot(global_rotation, frame.v1), dot(global_rotation, frame.v2), dot(global_rotation, frame.vn)};
}
inline Vec3 mitc4DirectorIncrement(const MITC4DirectorFrame& frame, const Vec3& global_rotation) {
const MITC4LocalRotations rotations = mitc4LocalRotations(frame, global_rotation);
return (-rotations.alpha) * frame.v2 + rotations.beta * frame.v1;
}
inline MITC4DisplacementDerivatives mitc4DisplacementDerivatives(const MITC4Geometry& geometry, const MITC4ElementDofVector& values,
Real xi, Real eta, Real zeta) {
MITC4DisplacementDerivatives result;
result.diagnostics = geometry.diagnostics;
result.shape = shapeFunctions(xi, eta);
for (std::size_t node = 0; node < 4; ++node) {
const Vec3 translation = mitc4NodalTranslation(values, node);
const Vec3 rotation = mitc4NodalRotation(values, node);
const Vec3 q = mitc4DirectorIncrement(geometry.nodal_frames[node], rotation);
const Real n = result.shape.n[node];
const Real dn_dxi = result.shape.dr[node];
const Real dn_deta = result.shape.ds[node];
result.displacement = result.displacement + n * translation + (0.5 * zeta * geometry.thickness * n) * q;
result.du_dxi = result.du_dxi + dn_dxi * translation + (0.5 * zeta * geometry.thickness * dn_dxi) * q;
result.du_deta = result.du_deta + dn_deta * translation + (0.5 * zeta * geometry.thickness * dn_deta) * q;
result.du_dzeta = result.du_dzeta + (0.5 * geometry.thickness * n) * q;
}
return result;
}
inline void assignMITC4CovariantStrain(MITC4StrainVector& values, const MITC4IntegrationBasis& basis,
const MITC4DisplacementDerivatives& derivatives) {
values[strainComponentIndex(MITC4StrainComponent::Eps11)] = dot(derivatives.du_dxi, basis.g1);
values[strainComponentIndex(MITC4StrainComponent::Eps22)] = dot(derivatives.du_deta, basis.g2);
values[strainComponentIndex(MITC4StrainComponent::Eps33)] = 0.0;
values[strainComponentIndex(MITC4StrainComponent::Gamma23)] = dot(derivatives.du_deta, basis.g3) + dot(derivatives.du_dzeta, basis.g2);
values[strainComponentIndex(MITC4StrainComponent::Gamma13)] = dot(derivatives.du_dxi, basis.g3) + dot(derivatives.du_dzeta, basis.g1);
values[strainComponentIndex(MITC4StrainComponent::Gamma12)] = dot(derivatives.du_dxi, basis.g2) + dot(derivatives.du_deta, basis.g1);
}
inline MITC4StrainEvaluation mitc4DirectCovariantStrain(const MITC4Geometry& geometry, const MITC4ElementDofVector& values,
Real xi, Real eta, Real zeta) {
MITC4StrainEvaluation result;
const auto basis = computeMITC4IntegrationBasis(geometry, xi, eta, zeta);
appendDiagnostics(result.diagnostics, basis.diagnostics);
const auto derivatives = mitc4DisplacementDerivatives(geometry, values, xi, eta, zeta);
appendDiagnostics(result.diagnostics, derivatives.diagnostics);
if (hasError(result.diagnostics)) {
return result;
}
assignMITC4CovariantStrain(result.values, basis, derivatives);
return result;
}
inline MITC4StrainRows mitc4DirectCovariantStrainRows(const MITC4Geometry& geometry, Real xi, Real eta, Real zeta) {
MITC4StrainRows result;
const auto basis = computeMITC4IntegrationBasis(geometry, xi, eta, zeta);
appendDiagnostics(result.diagnostics, basis.diagnostics);
if (hasError(result.diagnostics)) {
return result;
}
for (std::size_t dof = 0; dof < 24; ++dof) {
MITC4ElementDofVector unit{};
unit.fill(0.0);
unit[dof] = 1.0;
const auto derivatives = mitc4DisplacementDerivatives(geometry, unit, xi, eta, zeta);
appendDiagnostics(result.diagnostics, derivatives.diagnostics);
if (hasError(result.diagnostics)) {
return result;
}
MITC4StrainVector values{};
assignMITC4CovariantStrain(values, basis, derivatives);
for (std::size_t component = 0; component < 6; ++component) {
result.rows[component][dof] = values[component];
}
}
return result;
}
inline MITC4StrainEvaluation evaluateMITC4StrainRows(const MITC4StrainRows& rows, const MITC4ElementDofVector& values) {
MITC4StrainEvaluation result;
result.diagnostics = rows.diagnostics;
if (hasError(result.diagnostics)) {
return result;
}
for (std::size_t component = 0; component < 6; ++component) {
for (std::size_t dof = 0; dof < 24; ++dof) {
result.values[component] += rows.rows[component][dof] * values[dof];
}
}
return result;
}
inline MITC4StrainRows mitc4TiedCovariantStrainRows(const MITC4Geometry& geometry, Real xi, Real eta, Real zeta) {
MITC4StrainRows result = mitc4DirectCovariantStrainRows(geometry, xi, eta, zeta);
const auto direct_a = mitc4DirectCovariantStrainRows(geometry, 0.0, -1.0, zeta);
const auto direct_b = mitc4DirectCovariantStrainRows(geometry, -1.0, 0.0, zeta);
const auto direct_c = mitc4DirectCovariantStrainRows(geometry, 0.0, 1.0, zeta);
const auto direct_d = mitc4DirectCovariantStrainRows(geometry, 1.0, 0.0, zeta);
appendDiagnostics(result.diagnostics, direct_a.diagnostics);
appendDiagnostics(result.diagnostics, direct_b.diagnostics);
appendDiagnostics(result.diagnostics, direct_c.diagnostics);
appendDiagnostics(result.diagnostics, direct_d.diagnostics);
if (hasError(result.diagnostics)) {
return result;
}
const std::size_t gamma23 = strainComponentIndex(MITC4StrainComponent::Gamma23);
const std::size_t gamma13 = strainComponentIndex(MITC4StrainComponent::Gamma13);
for (std::size_t dof = 0; dof < 24; ++dof) {
result.rows[gamma13][dof] = 0.5 * (1.0 - eta) * direct_a.rows[gamma13][dof] +
0.5 * (1.0 + eta) * direct_c.rows[gamma13][dof];
result.rows[gamma23][dof] = 0.5 * (1.0 - xi) * direct_b.rows[gamma23][dof] +
0.5 * (1.0 + xi) * direct_d.rows[gamma23][dof];
}
return result;
}
inline LocalBasis computeLocalBasis(const std::array<Vec3, 4>& coordinates) {
const MITC4Geometry geometry = buildMITC4Geometry(coordinates, 1.0);
if (!geometry.ok()) {