Line data    Source code

       1             : // The libMesh Finite Element Library.
       2             : // Copyright (C) 2002-2026 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_FACE_TRI6_H
      21             : #define LIBMESH_FACE_TRI6_H
      22             : 
      23             : // Local includes
      24             : #include "libmesh/libmesh_common.h"
      25             : #include "libmesh/fe_reference_element_traits.h"
      26             : #include "libmesh/face_tri.h"
      27             : 
      28             : namespace libMesh
      29             : {
      30             : 
      31             : /**
      32             :  * The \p Tri6 is an element in 2D composed of 6 nodes.  It is
      33             :  * numbered like this:
      34             :  *
      35             :  * \verbatim
      36             :  *   TRI6:
      37             :  *    2
      38             :  *    o
      39             :  *    |\
      40             :  *    | \
      41             :  *    |  \            eta
      42             :  *    |   \            ^
      43             :  *    |    \           |
      44             :  *  5 o     o 4        |
      45             :  *    |      \         o---> xi
      46             :  *    |       \
      47             :  *    |        \
      48             :  *    o----o----o
      49             :  *    0    3    1
      50             :  * \endverbatim
      51             :  *
      52             :  * (xi, eta): { 0 <= xi  <= 1
      53             :  *            { 0 <= eta <= 1
      54             :  *            { xi + eta <= 1
      55             :  * are the reference element coordinates associated with the given
      56             :  * numbering.
      57             :  *
      58             :  * \author Benjamin S. Kirk
      59             :  * \date 2002
      60             :  * \brief A 2D triangular element with 6 nodes.
      61             :  */
      62             : class Tri6 : public Tri
      63             : {
      64             : public:
      65             : 
      66             :   /**
      67             :    * Constructor.  By default this element has no parent.
      68             :    */
      69             :   explicit
      70      938705 :   Tri6 (Elem * p=nullptr) :
      71      938705 :     Tri(num_nodes, p, _nodelinks_data) {}
      72             : 
      73             :   Tri6 (Tri6 &&) = delete;
      74             :   Tri6 (const Tri6 &) = delete;
      75             :   Tri6 & operator= (const Tri6 &) = delete;
      76             :   Tri6 & operator= (Tri6 &&) = delete;
      77     1114610 :   virtual ~Tri6() = default;
      78             : 
      79             :   /**
      80             :    * \returns \p TRI6.
      81             :    */
      82  4562162110 :   virtual ElemType type () const override { return TRI6; }
      83             : 
      84             :   /**
      85             :    * \returns 6.
      86             :    */
      87  2015473390 :   virtual unsigned int n_nodes() const override { return num_nodes; }
      88             : 
      89             :   /**
      90             :    * \returns 4.
      91             :    */
      92           0 :   virtual unsigned int n_sub_elem() const override { return 4; }
      93             : 
      94             :   /**
      95             :    * \returns \p true if the specified (local) node number is a vertex.
      96             :    */
      97             :   virtual bool is_vertex(const unsigned int i) const override;
      98             : 
      99             :   /**
     100             :    * \returns \p true if the specified (local) node number is an edge.
     101             :    */
     102             :   virtual bool is_edge(const unsigned int i) const override;
     103             : 
     104             :   /**
     105             :    * \returns \p true if the specified (local) node number is a face.
     106             :    */
     107             :   virtual bool is_face(const unsigned int i) const override;
     108             : 
     109             :   /**
     110             :    * \returns \p true if the specified (local) node number is on the
     111             :    * specified side.
     112             :    */
     113             :   virtual bool is_node_on_side(const unsigned int n,
     114             :                                const unsigned int s) const override;
     115             : 
     116             :   virtual std::vector<unsigned int> nodes_on_side(const unsigned int s) const override;
     117             : 
     118             :   virtual std::vector<unsigned int> nodes_on_edge(const unsigned int e) const override;
     119             : 
     120             :   /**
     121             :    * \returns \p true if the specified (local) node number is on the
     122             :    * specified edge (== is_node_on_side in 2D).
     123             :    */
     124        4371 :   virtual bool is_node_on_edge(const unsigned int n,
     125             :                                const unsigned int e) const override
     126        4371 :   { return this->is_node_on_side(n,e); }
     127             : 
     128             :   /**
     129             :    * \returns \p true if the element map is definitely affine within
     130             :    * numerical tolerances.
     131             :    */
     132             :   virtual bool has_affine_map () const override;
     133             : 
     134             :   /**
     135             :    * \returns SECOND.
     136             :    */
     137             :   virtual Order default_order() const override;
     138             : 
     139             :   /**
     140             :    * Don't hide Elem::key() defined in the base class.
     141             :    */
     142             :   using Elem::key;
     143             : 
     144             :   /**
     145             :    * \returns An id associated with the \p s side of this element.
     146             :    * The id is not necessarily unique, but should be close.
     147             :    *
     148             :    * We reimplement this method here for the \p Tri6 since we can
     149             :    * use the center node of each edge to provide a perfect (unique)
     150             :    * key.
     151             :    */
     152             :   virtual dof_id_type key (const unsigned int s) const override;
     153             : 
     154             :   /**
     155             :    * \returns \p Tri6::side_nodes_map[side][side_node] after doing some range checking.
     156             :    */
     157             :   virtual unsigned int local_side_node(unsigned int side,
     158             :                                        unsigned int side_node) const override;
     159             : 
     160             :   virtual std::unique_ptr<Elem> build_side_ptr (const unsigned int i) override;
     161             : 
     162             :   /**
     163             :    * Rebuilds an EDGE2 coincident with face i.
     164             :    */
     165             :   virtual void build_side_ptr (std::unique_ptr<Elem> & elem,
     166             :                                const unsigned int i) override;
     167             : 
     168             :   // Avoid hiding deprecated version with different signature
     169             :   using Elem::build_side_ptr;
     170             : 
     171             :   virtual void connectivity(const unsigned int sf,
     172             :                             const IOPackage iop,
     173             :                             std::vector<dof_id_type> & conn) const override;
     174             : 
     175             :   /**
     176             :    * \returns 2 for all \p n.
     177             :    */
     178        9965 :   virtual unsigned int n_second_order_adjacent_vertices (const unsigned int) const override
     179        9965 :   { return 2; }
     180             : 
     181             :   /**
     182             :    * \returns The element-local number of the  \f$ v^{th} \f$ vertex
     183             :    * that defines the \f$ n^{th} \f$ second-order node.
     184             :    *
     185             :    * \note \p n is counted as depicted above, \f$ 3 \le n < 6 \f$.
     186             :    */
     187             :   virtual unsigned short int second_order_adjacent_vertex (const unsigned int n,
     188             :                                                            const unsigned int v) const override;
     189             : 
     190             :   /**
     191             :    * \returns The child number \p c and element-local index \p v of the
     192             :    * \f$ n^{th} \f$ second-order node on the parent element.  See
     193             :    * elem.h for further details.
     194             :    */
     195             :   virtual std::pair<unsigned short int, unsigned short int>
     196             :   second_order_child_vertex (const unsigned int n) const override;
     197             : 
     198             :   /**
     199             :    * Geometric constants for Tri6.
     200             :    */
     201             :   static const int num_nodes = 6;
     202             :   static const int nodes_per_side = 3;
     203             : 
     204             :   /**
     205             :    * This maps the \f$ j^{th} \f$ node of the \f$ i^{th} \f$ side to
     206             :    * element node numbers.
     207             :    */
     208             :   static const ReferenceElementTable<num_sides, nodes_per_side> side_nodes_map;
     209             : 
     210             :   /**
     211             :    * An optimized method for approximating the area of a
     212             :    * TRI6 using quadrature.
     213             :    */
     214             :   virtual Real volume () const override;
     215             : 
     216             :   /**
     217             :    * \returns A bounding box (not necessarily the minimal bounding box)
     218             :    * containing the geometric element.
     219             :    */
     220             :   virtual BoundingBox loose_bounding_box () const override;
     221             : 
     222             :   virtual void permute(unsigned int perm_num) override final;
     223             : 
     224             :   virtual void flip(BoundaryInfo *) override final;
     225             : 
     226             :   unsigned int center_node_on_side(const unsigned short side) const override final;
     227             : 
     228             :   ElemType side_type (const unsigned int s) const override final;
     229             : 
     230             : protected:
     231             : 
     232             :   /**
     233             :    * Data for links to nodes.
     234             :    */
     235             :   Node * _nodelinks_data[num_nodes];
     236             : 
     237             : 
     238             : 
     239             : #ifdef LIBMESH_ENABLE_AMR
     240             : 
     241             :   /**
     242             :    * Matrix used to create the elements children.
     243             :    */
     244      632532 :   virtual Real embedding_matrix (const unsigned int i,
     245             :                                  const unsigned int j,
     246             :                                  const unsigned int k) const override
     247      632532 :   { return _embedding_matrix[i][j][k]; }
     248             : 
     249             :   /**
     250             :    * Matrix that computes new nodal locations/solution values
     251             :    * from current nodes/solution.
     252             :    */
     253             :   static const Real _embedding_matrix[num_children][num_nodes][num_nodes];
     254             : 
     255      982332 :   LIBMESH_ENABLE_TOPOLOGY_CACHES;
     256             : 
     257             : #endif // LIBMESH_ENABLE_AMR
     258             : 
     259             : private:
     260             : 
     261             :   /**
     262             :    * Matrix that tells which vertices define the location
     263             :    * of mid-side (or second-order) nodes
     264             :    */
     265             :   static const unsigned short int _second_order_adjacent_vertices[num_sides][2];
     266             : 
     267             :   /**
     268             :    * Vector that names a child sharing each second order node.
     269             :    */
     270             :   static const unsigned short int _second_order_vertex_child_number[num_nodes];
     271             : 
     272             :   /**
     273             :    * Vector that names the child vertex index for each second order node.
     274             :    */
     275             :   static const unsigned short int _second_order_vertex_child_index[num_nodes];
     276             : };
     277             : 
     278             : 
     279             : } // namespace libMesh
     280             : 
     281             : #endif // LIBMESH_FACE_TRI6_H