StVenantKirchhoffModel_Def.hpp

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//*****************************************************************//
//    Albany 2.0:  Copyright 2012 Sandia Corporation               //
//    This Software is released under the BSD license detailed     //
//    in the file "license.txt" in the top-level Albany directory  //
//*****************************************************************//

#include <Intrepid_MiniTensor.h>
#include "Teuchos_TestForException.hpp"
#include "Phalanx_DataLayout.hpp"

namespace LCM
{

//------------------------------------------------------------------------------
template<typename EvalT, typename Traits>
StVenantKirchhoffModel<EvalT, Traits>::
StVenantKirchhoffModel(Teuchos::ParameterList* p,
    const Teuchos::RCP<Albany::Layouts>& dl) :
    LCM::ConstitutiveModel<EvalT, Traits>(p, dl)
{
  // define the dependent fields
  this->dep_field_map_.insert(std::make_pair("F", dl->qp_tensor));
  this->dep_field_map_.insert(std::make_pair("J", dl->qp_scalar));
  this->dep_field_map_.insert(std::make_pair("Poissons Ratio", dl->qp_scalar));
  this->dep_field_map_.insert(std::make_pair("Elastic Modulus", dl->qp_scalar));

  // define the evaluated fields
  std::string cauchy = (*field_name_map_)["Cauchy_Stress"];
  this->eval_field_map_.insert(std::make_pair(cauchy, dl->qp_tensor));

  // define the state variables
  this->num_state_variables_++;
  this->state_var_names_.push_back(cauchy);
  this->state_var_layouts_.push_back(dl->qp_tensor);
  this->state_var_init_types_.push_back("scalar");
  this->state_var_init_values_.push_back(0.0);
  this->state_var_old_state_flags_.push_back(false);
  this->state_var_output_flags_.push_back(true);
}
//------------------------------------------------------------------------------
template<typename EvalT, typename Traits>
void StVenantKirchhoffModel<EvalT, Traits>::
computeState(typename Traits::EvalData workset,
    std::map<std::string, Teuchos::RCP<PHX::MDField<ScalarT> > > dep_fields,
    std::map<std::string, Teuchos::RCP<PHX::MDField<ScalarT> > > eval_fields)
{
  // extract dependent MDFields
  PHX::MDField<ScalarT> def_grad = *dep_fields["F"];
  PHX::MDField<ScalarT> J = *dep_fields["J"];
  PHX::MDField<ScalarT> poissons_ratio = *dep_fields["Poissons Ratio"];
  PHX::MDField<ScalarT> elastic_modulus = *dep_fields["Elastic Modulus"];
  // extract evaluated MDFields
  std::string cauchy = (*field_name_map_)["Cauchy_Stress"];
  PHX::MDField<ScalarT> stress = *eval_fields[cauchy];
  ScalarT lambda;
  ScalarT mu;

  Intrepid::Tensor<ScalarT> F(num_dims_), C(num_dims_), sigma(num_dims_);
  Intrepid::Tensor<ScalarT> I(Intrepid::eye<ScalarT>(num_dims_));
  Intrepid::Tensor<ScalarT> S(num_dims_), E(num_dims_);

  for (std::size_t cell(0); cell < workset.numCells; ++cell) {
    for (std::size_t pt(0); pt < num_pts_; ++pt) {
      lambda = (elastic_modulus(cell, pt) * poissons_ratio(cell, pt))
          / (1. + poissons_ratio(cell, pt))
          / (1 - 2 * poissons_ratio(cell, pt));
      mu = elastic_modulus(cell, pt) / (2. * (1. + poissons_ratio(cell, pt)));
      F.fill(&def_grad(cell, pt, 0, 0));
      C = F * transpose(F);
      E = 0.5 * ( C - I );
      S = lambda * Intrepid::trace(E) * I + 2.0 * mu * E;
      sigma = (1.0 / Intrepid::det(F) ) * F * S * Intrepid::transpose(F);
      for (std::size_t i = 0; i < num_dims_; ++i) {
        for (std::size_t j = 0; j < num_dims_; ++j) {
          stress(cell, pt, i, j) = sigma(i, j);
        }
      }
    }
  }
}
//------------------------------------------------------------------------------
}