Cosserat-Continuum-Nonplanar

@osander: Can you have a look here?

This MR cleans up the usage of MIXED_SPACE in cosserat-continuum.

Now all combinations of dim = dimworld or dim != dimworld and MIXED_SPACE = 0 or MIXED_SPACE = 1 at least compile.

Also, this MR points out the one combination that still can't be solved: Problems with dim != dimworld do not work for MIXED_SPACE = 1!

As soon as I need this for locking tests I will add this; I will have to change Nonplanarcosseratshellenergy so it can be assembled with the GFEMixedAssembler.

dune/gfe/nonplanarcosseratshellenergy.hh

@@ -23,7 +23,14 @@
 #include <dune/localfunctions/lagrange/lfecache.hh>
 #endif
 
-template<class Basis, int dim, class field_type=double, class GridFunction = 
+/** \brief Assembles the cosserat energy for a single element.
+ *
+ * \tparam Basis                       Type of the Basis used for assembling
+ * \tparam dim                         Dimension of the Targetspace, 3
+ * \tparam field_type                  The coordinate type of the TargetSpace
+ * \tparam StressFreeStateGridFunction Type of the GridFunction representing the Cosserat shell in a stress free state
+ */
+template<class Basis, int dim, class field_type=double, class StressFreeStateGridFunction = 
   Dune::Functions::DiscreteGlobalBasisFunction<Basis,std::vector<Dune::FieldVector<double, Basis::GridView::dimensionworld>> > >
 class NonplanarCosseratShellEnergy
   : public Dune::GFE::LocalEnergy<Basis,RigidBodyMotion<field_type,dim> >
@@ -43,14 +50,15 @@ class NonplanarCosseratShellEnergy
 public:
 
   /** \brief Constructor with a set of material parameters
-   * \param parameters The material parameters
+   * \param parameters                  The material parameters
+   * \param stressFreeStateGridFunction Pointer to a parametrization representing the Cosserat shell in a stress-free state
    */
   NonplanarCosseratShellEnergy(const Dune::ParameterTree& parameters,
-                               const GridFunction* gridFunctionPtr,
+                               const StressFreeStateGridFunction* stressFreeStateGridFunction,
                                const BoundaryPatch<GridView>* neumannBoundary,
                                const std::function<Dune::FieldVector<double,3>(Dune::FieldVector<double,dimworld>)> neumannFunction,
                                const std::function<Dune::FieldVector<double,3>(Dune::FieldVector<double,dimworld>)> volumeLoad)
-  : gridFunctionPtr_(gridFunctionPtr),
+  : stressFreeStateGridFunction_(stressFreeStateGridFunction),
     neumannBoundary_(neumannBoundary),
     neumannFunction_(neumannFunction),
     volumeLoad_(volumeLoad)
@@ -117,7 +125,7 @@ public:
   double b1_, b2_, b3_;
 
   /** \brief The geometry used for assembling */
-  const GridFunction* gridFunctionPtr_;
+  const StressFreeStateGridFunction* stressFreeStateGridFunction_;
 
   /** \brief The Neumann boundary */
   const BoundaryPatch<GridView>* neumannBoundary_;
@@ -129,9 +137,9 @@ public:
   const std::function<Dune::FieldVector<double,3>(Dune::FieldVector<double,dimworld>)> volumeLoad_;
 };
 
-template <class Basis, int dim, class field_type, class GridFunction>
-typename NonplanarCosseratShellEnergy<Basis, dim, field_type, GridFunction>::RT
-NonplanarCosseratShellEnergy<Basis,dim,field_type, GridFunction>::
+template <class Basis, int dim, class field_type, class StressFreeStateGridFunction>
+typename NonplanarCosseratShellEnergy<Basis, dim, field_type, StressFreeStateGridFunction>::RT
+NonplanarCosseratShellEnergy<Basis,dim,field_type, StressFreeStateGridFunction>::
 energy(const typename Basis::LocalView& localView,
        const std::vector<RigidBodyMotion<field_type,dim> >& localSolution) const
 {
@@ -139,15 +147,18 @@ energy(const typename Basis::LocalView& localView,
   auto element = localView.element();
 
 #if HAVE_DUNE_CURVEDGEOMETRY
-  // Construct a curved geometry to use a better approximation of the geometry of the element
+  // Construct a curved geometry of this element of the Cosserat shell in stress-free state
+  // When using element.geometry(), then the curvatures on the element are zero, when using a curved geometry, they are not
+  // If a parametrization representing the Cosserat shell in a stress-free state is given,
+  // this is used for the curved geometry approximation.
   // The variable local holds the local coordinates in the reference element
   // and localGeometry.global maps them to the world coordinates
   Dune::CurvedGeometry<DT, gridDim, dimworld, Dune::CurvedGeometryTraits<DT, Dune::LagrangeLFECache<DT,DT,gridDim>>> geometry(referenceElement(element),
     [this,element](const auto& local) {
-      if (not gridFunctionPtr_) {
+      if (not stressFreeStateGridFunction_) {
         return element.geometry().global(local);
       }
-      auto localGridFunction = localFunction(*gridFunctionPtr_);
+      auto localGridFunction = localFunction(*stressFreeStateGridFunction_);
       localGridFunction.bind(element);
       return localGridFunction(local);
     }, 2); /*order*/