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Commit e3b57423 authored by Oliver Sander's avatar Oliver Sander Committed by sander
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Hencky energy functional for finite strain materials

[[Imported from SVN: r9938]]
parent 9ebaaf23
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#ifndef DUNE_GFE_HENCKYENERGY_HH
#define DUNE_GFE_HENCKYENERGY_HH
#include <dune/common/fmatrix.hh>
#include <dune/geometry/quadraturerules.hh>
#include <dune/fufem/functions/virtualgridfunction.hh>
#include <dune/fufem/boundarypatch.hh>
#include <dune/gfe/localgeodesicfestiffness.hh>
#include <dune/gfe/localfestiffness.hh>
#include <dune/gfe/localgeodesicfefunction.hh>
#include <dune/gfe/realtuple.hh>
#include <dune/gfe/eigenvalues.hh>
namespace Dune {
namespace Fufem {
template<class GridView, class LocalFiniteElement, class field_type=double>
class HenckyEnergy
: public LocalFEStiffness<GridView,LocalFiniteElement,std::vector<Dune::FieldVector<field_type,3> > >
{
// grid types
typedef typename GridView::Grid::ctype DT;
typedef typename GridView::template Codim<0>::Entity Entity;
// some other sizes
enum {gridDim=GridView::dimension};
enum {dim=GridView::dimension};
public: // for testing
/** \brief Constructor with a set of material parameters
* \param parameters The material parameters
*/
HenckyEnergy(const Dune::ParameterTree& parameters,
const BoundaryPatch<GridView>* neumannBoundary,
const Dune::VirtualFunction<Dune::FieldVector<double,gridDim>, Dune::FieldVector<double,3> >* neumannFunction)
: neumannBoundary_(neumannBoundary),
neumannFunction_(neumannFunction)
{
// Lame constants
mu_ = parameters.template get<double>("mu");
lambda_ = parameters.template get<double>("lambda");
}
/** \brief Assemble the energy for a single element */
field_type energy (const Entity& e,
const LocalFiniteElement& localFiniteElement,
const std::vector<Dune::FieldVector<field_type,gridDim> >& localConfiguration,
const std::vector<Dune::FieldVector<double,gridDim> >& localPointLoads) const;
/** \brief Lame constants */
double mu_, lambda_;
/** \brief The Neumann boundary */
const BoundaryPatch<GridView>* neumannBoundary_;
/** \brief The function implementing the Neumann data */
const Dune::VirtualFunction<Dune::FieldVector<double,gridDim>, Dune::FieldVector<double,3> >* neumannFunction_;
};
template <class GridView, class LocalFiniteElement, class field_type>
field_type
HenckyEnergy<GridView,LocalFiniteElement,field_type>::
energy(const Entity& element,
const LocalFiniteElement& localFiniteElement,
const std::vector<Dune::FieldVector<field_type,gridDim> >& localConfiguration,
const std::vector<Dune::FieldVector<double,gridDim> >& localPointLoads) const
{
assert(element.type() == localFiniteElement.type());
typedef typename GridView::template Codim<0>::Entity::Geometry Geometry;
field_type energy = 0;
// typedef LocalGeodesicFEFunction<gridDim, DT, LocalFiniteElement, TargetSpace> LocalGFEFunctionType;
// LocalGFEFunctionType localGeodesicFEFunction(localFiniteElement,localConfiguration);
// store gradients of shape functions and base functions
std::vector<Dune::FieldMatrix<DT,1,gridDim> > referenceGradients(localFiniteElement.localBasis().size());
std::vector<Dune::FieldVector<DT,gridDim> > gradients(localFiniteElement.localBasis().size());
int quadOrder = (element.type().isSimplex()) ? localFiniteElement.localBasis().order()
: localFiniteElement.localBasis().order() * gridDim;
const Dune::QuadratureRule<DT, gridDim>& quad
= Dune::QuadratureRules<DT, gridDim>::rule(element.type(), quadOrder);
for (size_t pt=0; pt<quad.size(); pt++) {
// Local position of the quadrature point
const Dune::FieldVector<DT,gridDim>& quadPos = quad[pt].position();
const DT integrationElement = element.geometry().integrationElement(quadPos);
const typename Geometry::JacobianInverseTransposed& jacobianInverseTransposed = element.geometry().jacobianInverseTransposed(quadPos);
DT weight = quad[pt].weight() * integrationElement;
#if 1
// get gradients of shape functions
localFiniteElement.localBasis().evaluateJacobian(quadPos, referenceGradients);
// compute gradients of base functions
for (size_t i=0; i<gradients.size(); ++i) {
// transform gradients
jacobianInverseTransposed.mv(referenceGradients[i][0], gradients[i]);
}
#endif
#if 0
// The derivative of the local function defined on the reference element
typename LocalGFEFunctionType::DerivativeType referenceDerivative = localGeodesicFEFunction.evaluateDerivative(quadPos);
// The derivative of the function defined on the actual element
typename LocalGFEFunctionType::DerivativeType derivative(0);
for (size_t comp=0; comp<referenceDerivative.N(); comp++)
jacobianInverseTransposed.umv(referenceDerivative[comp], derivative[comp]);
#endif
Dune::FieldMatrix<field_type,gridDim,gridDim> derivative(0);
for (size_t i=0; i<gradients.size(); i++)
for (int j=0; j<gridDim; j++)
derivative[j].axpy(localConfiguration[i][j], gradients[i]);
/////////////////////////////////////////////////////////
// compute F^T F
/////////////////////////////////////////////////////////
Dune::FieldMatrix<field_type,gridDim,gridDim> FTF(0);
for (int i=0; i<gridDim; i++)
for (int j=0; j<gridDim; j++)
for (int k=0; k<gridDim; k++)
FTF[i][j] += derivative[k][i] * derivative[k][j];
//////////////////////////////////////////////////////////
// Eigenvalues of FTF
//////////////////////////////////////////////////////////
#if 0 // hencky
std::array<field_type,dim> lambda = eigenValues(FTF);
//////////////////////////////////////////////////////////
// Compute the derivative of the rotation
// Note: we need it in matrix coordinates
//////////////////////////////////////////////////////////
// logarithms of the eigenvalues
std::array<field_type,dim> ln;
for (int i=0; i<dim; i++)
ln[i] = std::log(lambda[i]);
// Add the local energy density
for (int i=0; i<dim; i++)
energy += weight * mu_ * ln[i]*ln[i];
field_type trace = 0;
for (int i=0; i<dim; i++)
trace += ln[i];
energy += weight * 0.5 * lambda_ * trace * trace;
#else // St.Venant-Kirchhoff
Dune::FieldMatrix<field_type,dim,dim> E = FTF;
for (int i=0; i<dim; i++)
E[i][i] -= 1.0;
E *= 0.5;
field_type trE = E[0][0] + E[1][1] + E[2][2];
Dune::FieldMatrix<field_type,dim,dim> ESquared = E*E;
field_type trESquared = ESquared[0][0] + ESquared[1][1] + ESquared[2][2];
energy += weight * mu_ * trESquared + weight * 0.5 * lambda_ * trE * trE;
#endif
}
//////////////////////////////////////////////////////////////////////////////
// Assemble boundary contributions
//////////////////////////////////////////////////////////////////////////////
for (size_t i=0; i<localPointLoads.size(); i++)
for (size_t j=0; j<dim; j++)
energy -= localConfiguration[i][j] * localPointLoads[i][j];
if (not neumannFunction_)
return energy;
for (typename Entity::LeafIntersectionIterator it = element.ileafbegin(); it != element.ileafend(); ++it) {
if (not neumannBoundary_ or not neumannBoundary_->contains(*it))
continue;
const Dune::QuadratureRule<DT, gridDim-1>& quad
= Dune::QuadratureRules<DT, gridDim-1>::rule(it->type(), quadOrder);
for (size_t pt=0; pt<quad.size(); pt++) {
// Local position of the quadrature point
const Dune::FieldVector<DT,gridDim>& quadPos = it->geometryInInside().global(quad[pt].position());
const DT integrationElement = it->geometry().integrationElement(quad[pt].position());
// The value of the local function
//RealTuple<field_type,dim> value = localGeodesicFEFunction.evaluate(quadPos);
// get gradients of shape functions
std::vector<Dune::FieldVector<DT,1> > shapeFunctionValues;
localFiniteElement.localBasis().evaluateFunction(quadPos, shapeFunctionValues);
Dune::FieldVector<field_type,dim> value(0);
for (int i=0; i<localFiniteElement.size(); i++)
for (int j=0; j<dim; j++)
value[j] += shapeFunctionValues[i] * localConfiguration[i][j];
// Value of the Neumann data at the current position
Dune::FieldVector<double,3> neumannValue;
if (dynamic_cast<const VirtualGridViewFunction<GridView,Dune::FieldVector<double,3> >*>(neumannFunction_))
dynamic_cast<const VirtualGridViewFunction<GridView,Dune::FieldVector<double,3> >*>(neumannFunction_)->evaluateLocal(element, quadPos, neumannValue);
else
neumannFunction_->evaluate(it->geometry().global(quad[pt].position()), neumannValue);
// Only translational dofs are affected by the Neumann force
for (size_t i=0; i<neumannValue.size(); i++)
energy += (neumannValue[i] * value[i]) * quad[pt].weight() * integrationElement;
}
}
return energy;
}
} // namespace Fufem
} // namespace Dune
template<class GridView, class LocalFiniteElement, int dim, class field_type=double>
class HenckyEnergy
: public LocalGeodesicFEStiffness<GridView,LocalFiniteElement,RealTuple<field_type,dim> >
{
// grid types
typedef typename GridView::Grid::ctype DT;
typedef RealTuple<field_type,dim> TargetSpace;
typedef typename TargetSpace::ctype RT;
typedef typename GridView::template Codim<0>::Entity Entity;
// some other sizes
enum {gridDim=GridView::dimension};
public: // for testing
/** \brief Constructor with a set of material parameters
* \param parameters The material parameters
*/
HenckyEnergy(const Dune::ParameterTree& parameters,
const BoundaryPatch<GridView>* neumannBoundary,
const Dune::VirtualFunction<Dune::FieldVector<double,gridDim>, Dune::FieldVector<double,3> >* neumannFunction)
: neumannBoundary_(neumannBoundary),
neumannFunction_(neumannFunction)
{
// Lame constants
mu_ = parameters.template get<double>("mu");
lambda_ = parameters.template get<double>("lambda");
}
/** \brief Assemble the energy for a single element */
RT energy (const Entity& e,
const LocalFiniteElement& localFiniteElement,
const std::vector<TargetSpace>& localSolution) const;
/** \brief Lame constants */
double mu_, lambda_;
/** \brief The Neumann boundary */
const BoundaryPatch<GridView>* neumannBoundary_;
/** \brief The function implementing the Neumann data */
const Dune::VirtualFunction<Dune::FieldVector<double,gridDim>, Dune::FieldVector<double,3> >* neumannFunction_;
};
template <class GridView, class LocalFiniteElement, int dim, class field_type>
typename HenckyEnergy<GridView,LocalFiniteElement,dim,field_type>::RT
HenckyEnergy<GridView,LocalFiniteElement,dim,field_type>::
energy(const Entity& element,
const LocalFiniteElement& localFiniteElement,
const std::vector<RealTuple<field_type,dim> >& localConfiguration) const
{
assert(element.type() == localFiniteElement.type());
typedef typename GridView::template Codim<0>::Entity::Geometry Geometry;
RT energy = 0;
typedef LocalGeodesicFEFunction<gridDim, DT, LocalFiniteElement, TargetSpace> LocalGFEFunctionType;
LocalGFEFunctionType localGeodesicFEFunction(localFiniteElement,localConfiguration);
int quadOrder = (element.type().isSimplex()) ? localFiniteElement.localBasis().order()
: localFiniteElement.localBasis().order() * gridDim;
const Dune::QuadratureRule<DT, gridDim>& quad
= Dune::QuadratureRules<DT, gridDim>::rule(element.type(), quadOrder);
for (size_t pt=0; pt<quad.size(); pt++) {
// Local position of the quadrature point
const Dune::FieldVector<DT,gridDim>& quadPos = quad[pt].position();
const DT integrationElement = element.geometry().integrationElement(quadPos);
const typename Geometry::JacobianInverseTransposed& jacobianInverseTransposed = element.geometry().jacobianInverseTransposed(quadPos);
DT weight = quad[pt].weight() * integrationElement;
// The derivative of the local function defined on the reference element
typename LocalGFEFunctionType::DerivativeType referenceDerivative = localGeodesicFEFunction.evaluateDerivative(quadPos);
// The derivative of the function defined on the actual element
typename LocalGFEFunctionType::DerivativeType derivative(0);
for (size_t comp=0; comp<referenceDerivative.N(); comp++)
jacobianInverseTransposed.umv(referenceDerivative[comp], derivative[comp]);
/////////////////////////////////////////////////////////
// compute F^T F
/////////////////////////////////////////////////////////
Dune::FieldMatrix<field_type,dim,dim> FTF(0);
for (int i=0; i<dim; i++)
for (int j=0; j<dim; j++)
for (int k=0; k<dim; k++)
FTF[i][j] += derivative[k][i] * derivative[k][j];
//////////////////////////////////////////////////////////
// Eigenvalues of FTF
//////////////////////////////////////////////////////////
#if 0 // hencky
std::array<field_type,dim> lambda = eigenValues(FTF);
//////////////////////////////////////////////////////////
// Compute the derivative of the rotation
// Note: we need it in matrix coordinates
//////////////////////////////////////////////////////////
// logarithms of the eigenvalues
std::array<field_type,dim> ln;
for (int i=0; i<dim; i++)
ln[i] = std::log(lambda[i]);
// Add the local energy density
for (int i=0; i<dim; i++)
energy += weight * mu_ * ln[i]*ln[i];
field_type trace = 0;
for (int i=0; i<dim; i++)
trace += ln[i];
energy += weight * 0.5 * lambda_ * trace * trace;
#else // St.Venant-Kirchhoff
Dune::FieldMatrix<field_type,dim,dim> E = FTF;
for (int i=0; i<dim; i++)
E[i][i] -= 1.0;
E *= 0.5;
field_type trE = E[0][0] + E[1][1] + E[2][2];
Dune::FieldMatrix<field_type,dim,dim> ESquared = E*E;
field_type trESquared = ESquared[0][0] + ESquared[1][1] + ESquared[2][2];
energy += weight * mu_ * trESquared + weight * 0.5 * lambda_ * trE * trE;
#endif
}
//////////////////////////////////////////////////////////////////////////////
// Assemble boundary contributions
//////////////////////////////////////////////////////////////////////////////
if (not neumannFunction_)
return energy;
for (typename Entity::LeafIntersectionIterator it = element.ileafbegin(); it != element.ileafend(); ++it) {
if (not neumannBoundary_ or not neumannBoundary_->contains(*it))
continue;
const Dune::QuadratureRule<DT, gridDim-1>& quad
= Dune::QuadratureRules<DT, gridDim-1>::rule(it->type(), quadOrder);
for (size_t pt=0; pt<quad.size(); pt++) {
// Local position of the quadrature point
const Dune::FieldVector<DT,gridDim>& quadPos = it->geometryInInside().global(quad[pt].position());
const DT integrationElement = it->geometry().integrationElement(quad[pt].position());
// The value of the local function
RealTuple<field_type,dim> value = localGeodesicFEFunction.evaluate(quadPos);
// Value of the Neumann data at the current position
Dune::FieldVector<double,3> neumannValue;
if (dynamic_cast<const VirtualGridViewFunction<GridView,Dune::FieldVector<double,3> >*>(neumannFunction_))
dynamic_cast<const VirtualGridViewFunction<GridView,Dune::FieldVector<double,3> >*>(neumannFunction_)->evaluateLocal(element, quadPos, neumannValue);
else
neumannFunction_->evaluate(it->geometry().global(quad[pt].position()), neumannValue);
// Only translational dofs are affected by the Neumann force
for (size_t i=0; i<neumannValue.size(); i++)
energy += (neumannValue[i] * value.globalCoordinates()[i]) * quad[pt].weight() * integrationElement;
}
}
return energy;
}
#endif //#ifndef COSSERAT_ENERGY_LOCAL_STIFFNESS_HH
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