Line data    Source code

       1             : // The libMesh Finite Element Library.
       2             : // Copyright (C) 2002-2025 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner
       3             : 
       4             : // This library is free software; you can redistribute it and/or
       5             : // modify it under the terms of the GNU Lesser General Public
       6             : // License as published by the Free Software Foundation; either
       7             : // version 2.1 of the License, or (at your option) any later version.
       8             : 
       9             : // This library is distributed in the hope that it will be useful,
      10             : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12             : // Lesser General Public License for more details.
      13             : 
      14             : // You should have received a copy of the GNU Lesser General Public
      15             : // License along with this library; if not, write to the Free Software
      16             : // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      17             : 
      18             : 
      19             : 
      20             : #ifndef LIBMESH_CELL_HEX8_H
      21             : #define LIBMESH_CELL_HEX8_H
      22             : 
      23             : // Local includes
      24             : #include "libmesh/cell_hex.h"
      25             : 
      26             : namespace libMesh
      27             : {
      28             : 
      29             : /**
      30             :  * The \p Hex8 is an element in 3D composed of 8 nodes.  It is
      31             :  * numbered like this:
      32             :  *
      33             :  * \verbatim
      34             :  *   HEX8: 7        6
      35             :  *         o--------z
      36             :  *        /:       /|         zeta
      37             :  *       / :      / |          ^   eta (into page)
      38             :  *    4 /  :   5 /  |          | /
      39             :  *     o--------o   |          |/
      40             :  *     |   o....|...o 2        o---> xi
      41             :  *     |  .3    |  /
      42             :  *     | .      | /
      43             :  *     |.       |/
      44             :  *     o--------o
      45             :  *     0        1
      46             :  * \endverbatim
      47             :  *
      48             :  * (xi, eta, zeta) in [-1,1]^3 are the reference element coordinates
      49             :  * associated with the given numbering.
      50             :  *
      51             :  * \author Benjamin S. Kirk
      52             :  * \date 2002
      53             :  * \brief A 3D hexahedral element with 8 nodes.
      54             :  */
      55             : class Hex8 final : public Hex
      56             : {
      57             : public:
      58             : 
      59             :   /**
      60             :    * Constructor.  By default this element has no parent.
      61             :    */
      62             :   explicit
      63     3100360 :   Hex8 (Elem * p=nullptr) :
      64     3100360 :     Hex(num_nodes, p, _nodelinks_data)
      65     3100360 :   {}
      66             : 
      67             :   Hex8 (Hex8 &&) = delete;
      68             :   Hex8 (const Hex8 &) = delete;
      69             :   Hex8 & operator= (const Hex8 &) = delete;
      70             :   Hex8 & operator= (Hex8 &&) = delete;
      71     3263179 :   virtual ~Hex8() = default;
      72             : 
      73             :   /**
      74             :    * \returns \p HEX8.
      75             :    */
      76  1437439230 :   virtual ElemType type () const override { return HEX8; }
      77             : 
      78             :   /**
      79             :    * \returns 8.
      80             :    */
      81   410057704 :   virtual unsigned int n_nodes() const override { return num_nodes; }
      82             : 
      83             :   /**
      84             :    * \returns 1.
      85             :    */
      86     1920009 :   virtual unsigned int n_sub_elem() const override { return 1; }
      87             : 
      88             :   /**
      89             :    * \returns \p true if the specified (local) node number is a vertex.
      90             :    */
      91             :   virtual bool is_vertex(const unsigned int i) const override;
      92             : 
      93             :   /**
      94             :    * \returns \p true if the specified (local) node number is an edge.
      95             :    */
      96             :   virtual bool is_edge(const unsigned int i) const override;
      97             : 
      98             :   /**
      99             :    * \returns \p true if the specified (local) node number is a face.
     100             :    */
     101             :   virtual bool is_face(const unsigned int i) const override;
     102             : 
     103             :   /**
     104             :    * \returns \p true if the specified (local) node number is on the
     105             :    * specified side.
     106             :    */
     107             :   virtual bool is_node_on_side(const unsigned int n,
     108             :                                const unsigned int s) const override;
     109             : 
     110             :   virtual std::vector<unsigned int> nodes_on_side(const unsigned int s) const override;
     111             : 
     112             :   virtual std::vector<unsigned int> nodes_on_edge(const unsigned int e) const override;
     113             : 
     114             :   /**
     115             :    * \returns \p true if the specified (local) node number is on the
     116             :    * specified edge.
     117             :    */
     118             :   virtual bool is_node_on_edge(const unsigned int n,
     119             :                                const unsigned int e) const override;
     120             : 
     121             :   /**
     122             :    * \returns \p true if the element map is definitely affine within
     123             :    * numerical tolerances.
     124             :    */
     125             :   virtual bool has_affine_map () const override;
     126             : 
     127             :   /**
     128             :    * \returns FIRST.
     129             :    */
     130             :   virtual Order default_order() const override;
     131             : 
     132             :   /**
     133             :    * Builds a QUAD4 built coincident with face i.
     134             :    * The \p std::unique_ptr<Elem> handles the memory aspect.
     135             :    */
     136             :   virtual std::unique_ptr<Elem> build_side_ptr (const unsigned int i) override;
     137             : 
     138             :   /**
     139             :    * Rebuilds a \p QUAD4 built coincident with face i.
     140             :    */
     141             :   virtual void build_side_ptr (std::unique_ptr<Elem> & elem,
     142             :                                const unsigned int i) override;
     143             : 
     144             :   // Avoid hiding deprecated version with different signature
     145             :   using Elem::build_side_ptr;
     146             : 
     147             :   /**
     148             :    * Builds a EDGE2 built coincident with edge i.
     149             :    * The \p std::unique_ptr<Elem> handles the memory aspect.
     150             :    */
     151             :   virtual std::unique_ptr<Elem> build_edge_ptr (const unsigned int i) override;
     152             : 
     153             :   /**
     154             :    * Rebuilds a \p EDGE2 built coincident with edge i.
     155             :    */
     156             :   virtual void build_edge_ptr (std::unique_ptr<Elem> & edge, const unsigned int i) override;
     157             : 
     158             :   virtual void connectivity(const unsigned int sc,
     159             :                             const IOPackage iop,
     160             :                             std::vector<dof_id_type> & conn) const override;
     161             : 
     162             :   /**
     163             :    * Geometric constants for Hex8.
     164             :    */
     165             :   static const int num_nodes = 8;
     166             :   static const int nodes_per_side = 4;
     167             :   static const int nodes_per_edge = 2;
     168             : 
     169             :   /**
     170             :    * This maps the \f$ j^{th} \f$ node of the \f$ i^{th} \f$ side to
     171             :    * element node numbers.
     172             :    */
     173             :   static const unsigned int side_nodes_map[num_sides][nodes_per_side];
     174             : 
     175             :   /**
     176             :    * This maps the \f$ j^{th} \f$ node of the \f$ i^{th} \f$ edge to
     177             :    * element node numbers.
     178             :    */
     179             :   static const unsigned int edge_nodes_map[num_edges][nodes_per_edge];
     180             : 
     181             :   /**
     182             :    * Class static helper function that computes the centroid of a
     183             :    * hexahedral region from a set of input points which are assumed to
     184             :    * be in the standard "Hex8" ordering, possibly with some duplicates
     185             :    * indicating a "degenerate" side. Hex8::true_centroid() and
     186             :    * Pyramid5::true_centroid() are implemented in terms of this
     187             :    * function.
     188             :    */
     189             :   static Point centroid_from_points(
     190             :     const Point & x0, const Point & x1, const Point & x2, const Point & x3,
     191             :     const Point & x4, const Point & x5, const Point & x6, const Point & x7);
     192             : 
     193             :   /**
     194             :    * We compute the centroid of the Hex using a customized numerical
     195             :    * quadrature approach that avoids unnecessary object creation/heap
     196             :    * allocations.
     197             :    */
     198             :   virtual Point true_centroid () const override;
     199             : 
     200             :   /**
     201             :    * A specialization for computing the area of a hexahedron
     202             :    * with flat sides.
     203             :    */
     204             :   virtual Real volume () const override;
     205             : 
     206             :   /**
     207             :    * Builds a bounding box out of the nodal positions
     208             :    */
     209             :   virtual BoundingBox loose_bounding_box () const override;
     210             : 
     211             :   virtual void permute(unsigned int perm_num) override final;
     212             : 
     213             :   virtual void flip(BoundaryInfo *) override final;
     214             : 
     215             :   ElemType side_type (const unsigned int s) const override final;
     216             : 
     217             : protected:
     218             : 
     219             :   /**
     220             :    * Data for links to nodes.
     221             :    */
     222             :   Node * _nodelinks_data[num_nodes];
     223             : 
     224             : 
     225             : 
     226             : #ifdef LIBMESH_ENABLE_AMR
     227             : 
     228             :   /**
     229             :    * Matrix used to create the elements children.
     230             :    */
     231     6576624 :   virtual Real embedding_matrix (const unsigned int i,
     232             :                                  const unsigned int j,
     233             :                                  const unsigned int k) const override
     234     6576624 :   { return _embedding_matrix[i][j][k]; }
     235             : 
     236             :   /**
     237             :    * Matrix that computes new nodal locations/solution values
     238             :    * from current nodes/solution.
     239             :    */
     240             :   static const Real _embedding_matrix[num_children][num_nodes][num_nodes];
     241             : 
     242    12917664 :   LIBMESH_ENABLE_TOPOLOGY_CACHES;
     243             : 
     244             : #endif // LIBMESH_ENABLE_AMR
     245             : };
     246             : 
     247             : } // namespace libMesh
     248             : 
     249             : #endif // LIBMESH_CELL_HEX8_H