Abstract base class for hyperelastic materials. Provides methods to compute...

Abstract base class for hyperelastic materials. Provides methods to compute the first and second derivative of a hyperelastic material at some configuration and evaluate the strain energy.

[[Imported from SVN: r12640]]

dune/elasticity/materials/material.hh

+// -*- tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+// vi: set ts=8 sw=4 et sts=4:
+#ifndef DUNE_ELASTICITY_MATERIALS_HYPERELASTIC_MATERIAL_HH
+#define DUNE_ELASTICITY_MATERIALS_HYPERELASTIC_MATERIAL_HH
+
+#include <dune/common/fvector.hh>
+#include <dune/common/fmatrix.hh>
+
+#include <dune/istl/bvector.hh>
+
+#include <dune/fufem/functions/virtualgridfunction.hh>
+#include <dune/fufem/assemblers/localfunctionalassembler.hh>
+#include <dune/fufem/assemblers/localoperatorassembler.hh>
+
+/* \brief Base class for hyperelastic materials. */
+template <class Basis>
+class Material
+{
+    public:
+        typedef Basis GlobalBasis;
+        typedef typename Basis::GridView::Grid GridType;
+        typedef typename Basis::LocalFiniteElement Lfe;    
+        typedef typename Basis::ReturnType ReturnType;    
+
+        static const int dim = GridType::dimension;
+        static const int dimworld = GridType::dimensionworld;
+
+        typedef Dune::FieldVector<ReturnType,dim> block_type;
+        typedef Dune::BlockVector<block_type> VectorType;
+        typedef LocalFunctionalAssembler<GridType,Lfe, block_type > LocalLinearization;
+        typedef LocalOperatorAssembler<GridType,Lfe,Lfe,Dune::FieldMatrix<ReturnType,dim,dim> > LocalHessian;
+
+        typedef Dune::VirtualFunction<block_type,block_type> Function;
+        typedef VirtualGridFunction<GridType, block_type> GridFunction;
+
+    public:
+        Material() {};
+
+        Material(const Basis& basis)
+        {
+            basis_ = &basis;
+        }
+
+
+        //! Evaluate the strain energy
+        virtual ReturnType energy(const GridFunction& displace) = 0;
+
+        //! Return the local assembler of the first derivative of the strain energy at some displacement
+        virtual LocalLinearization& firstDerivative(const GridFunction& displace) = 0;
+
+        //! Return the local assembler of the second derivative of the strain energy at some displacement
+        virtual LocalHessian& secondDerivative(const GridFunction& displace) = 0;
+
+        //! Return the global basis
+        const Basis& basis() {return *basis_;}
+
+    protected:
+        //! Global basis used for the spatial discretization
+        const Basis* basis_;
+};
+
+#endif