LinearElasticIsotropic.cpp

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#include "LinearElasticIsotropic.h"
 
#include "LogPenalty.h"
 
namespace MaterialLib
{
namespace Fracture
{
template <int DisplacementDim>
void LinearElasticIsotropic<DisplacementDim>::computeConstitutiveRelation(
    double const t,
    ParameterLib::SpatialPosition const& x,
    double const aperture0,
    Eigen::Ref<Eigen::VectorXd const>
        sigma0,
    Eigen::Ref<Eigen::VectorXd const>
    /*w_prev*/,
    Eigen::Ref<Eigen::VectorXd const>
        w,
    Eigen::Ref<Eigen::VectorXd const>
    /*sigma_prev*/,
    Eigen::Ref<Eigen::VectorXd>
        sigma,
    Eigen::Ref<Eigen::MatrixXd>
        C,
    typename FractureModelBase<DisplacementDim>::MaterialStateVariables&
        material_state_variables)
{
    material_state_variables.reset();
 
    const int index_ns = DisplacementDim - 1;
    C.setZero();
    for (int i = 0; i < index_ns; i++)
    {
        C(i, i) = _mp.shear_stiffness(t, x)[0];
    }
 
    sigma.noalias() = C * w;
 
    double const aperture = w[index_ns] + aperture0;
 
    sigma.coeffRef(index_ns) =
        _mp.normal_stiffness(t, x)[0] * w[index_ns] *
        logPenalty(aperture0, aperture, _penalty_aperture_cutoff);
 
    C(index_ns, index_ns) =
        _mp.normal_stiffness(t, x)[0] *
        logPenaltyDerivative(aperture0, aperture, _penalty_aperture_cutoff);
 
    sigma.noalias() += sigma0;
 
    // correction for an opening fracture
    if (_tension_cutoff && sigma[index_ns] > 0)
    {
        C.setZero();
        sigma.setZero();
        material_state_variables.setTensileStress(true);
    }
}
 
template class LinearElasticIsotropic<2>;
template class LinearElasticIsotropic<3>;
 
}  // namespace Fracture
}  // namespace MaterialLib