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/face_tri.h"
      26             : #include "libmesh/face_tri3.h"
      27             : #include "libmesh/fe_reference_element_traits.h"
      28             : 
      29             : namespace libMesh
      30             : {
      31             : 
      32             : /**
      33             :  * The \p Tri6 is an element in 2D composed of 6 nodes.  It is
      34             :  * numbered like this:
      35             :  *
      36             :  * \verbatim
      37             :  *   TRI6:
      38             :  *    2
      39             :  *    o
      40             :  *    |\
      41             :  *    | \
      42             :  *    |  \            eta
      43             :  *    |   \            ^
      44             :  *    |    \           |
      45             :  *  5 o     o 4        |
      46             :  *    |      \         o---> xi
      47             :  *    |       \
      48             :  *    |        \
      49             :  *    o----o----o
      50             :  *    0    3    1
      51             :  * \endverbatim
      52             :  *
      53             :  * (xi, eta): { 0 <= xi  <= 1
      54             :  *            { 0 <= eta <= 1
      55             :  *            { xi + eta <= 1
      56             :  * are the reference element coordinates associated with the given
      57             :  * numbering.
      58             :  *
      59             :  * \author Benjamin S. Kirk
      60             :  * \date 2002
      61             :  * \brief A 2D triangular element with 6 nodes.
      62             :  */
      63             : class Tri6 : public Tri
      64             : {
      65             : public:
      66             : 
      67             :   /**
      68             :    * Constructor.  By default this element has no parent.
      69             :    */
      70             :   explicit
      71     5399652 :   Tri6 (Elem * p=nullptr) :
      72     5399652 :     Tri(num_nodes, p, _nodelinks_data) {}
      73             : 
      74             :   Tri6 (Tri6 &&) = delete;
      75             :   Tri6 (const Tri6 &) = delete;
      76             :   Tri6 & operator= (const Tri6 &) = delete;
      77             :   Tri6 & operator= (Tri6 &&) = delete;
      78     5571983 :   virtual ~Tri6() = default;
      79             : 
      80             :   /**
      81             :    * \returns \p TRI6.
      82             :    */
      83 14992031954 :   virtual ElemType type () const override { return TRI6; }
      84             : 
      85             :   /**
      86             :    * \returns 6.
      87             :    */
      88  2082778912 :   virtual unsigned int n_nodes() const override { return num_nodes; }
      89             : 
      90             :   /**
      91             :    * \returns 4.
      92             :    */
      93           0 :   virtual unsigned int n_sub_elem() const override { return 4; }
      94             : 
      95             :   /**
      96             :    * \returns \p true if the specified (local) node number is a vertex.
      97             :    */
      98             :   virtual bool is_vertex(const unsigned int i) const override;
      99             : 
     100             :   /**
     101             :    * \returns \p true if the specified (local) node number is an edge.
     102             :    */
     103             :   virtual bool is_edge(const unsigned int i) const override;
     104             : 
     105             :   /**
     106             :    * \returns \p true if the specified (local) node number is a face.
     107             :    */
     108             :   virtual bool is_face(const unsigned int i) const override;
     109             : 
     110             :   /**
     111             :    * \returns \p true if the specified (local) node number is on the
     112             :    * specified side.
     113             :    */
     114             :   virtual bool is_node_on_side(const unsigned int n,
     115             :                                const unsigned int s) const override;
     116             : 
     117             :   virtual std::vector<unsigned int> nodes_on_side(const unsigned int s) const override;
     118             : 
     119             :   virtual std::vector<unsigned int> nodes_on_edge(const unsigned int e) const override;
     120             : 
     121             :   /**
     122             :    * \returns \p true if the specified (local) node number is on the
     123             :    * specified edge (== is_node_on_side in 2D).
     124             :    */
     125       48379 :   virtual bool is_node_on_edge(const unsigned int n,
     126             :                                const unsigned int e) const override
     127       48379 :   { return this->is_node_on_side(n,e); }
     128             : 
     129             :   /**
     130             :    * \returns \p true if the element map is definitely affine within
     131             :    * numerical tolerances.
     132             :    */
     133             :   virtual bool has_affine_map () const override;
     134             : 
     135             :   /**
     136             :    * \returns SECOND.
     137             :    */
     138             :   virtual Order default_order() const override;
     139             : 
     140             :   /**
     141             :    * Don't hide Elem::key() defined in the base class.
     142             :    */
     143             :   using Elem::key;
     144             : 
     145             :   /**
     146             :    * \returns An id associated with the \p s side of this element.
     147             :    * The id is not necessarily unique, but should be close.
     148             :    *
     149             :    * We reimplement this method here for the \p Tri6 since we can
     150             :    * use the center node of each edge to provide a perfect (unique)
     151             :    * key.
     152             :    */
     153             :   virtual dof_id_type key (const unsigned int s) const override;
     154             : 
     155             :   /**
     156             :    * \returns \p Tri6::side_nodes_map[side][side_node] after doing some range checking.
     157             :    */
     158             :   virtual unsigned int local_side_node(unsigned int side,
     159             :                                        unsigned int side_node) const override;
     160             : 
     161             :   virtual std::unique_ptr<Elem> build_side_ptr (const unsigned int i) override;
     162             : 
     163             :   /**
     164             :    * Rebuilds an EDGE2 coincident with face i.
     165             :    */
     166             :   virtual void build_side_ptr (std::unique_ptr<Elem> & elem,
     167             :                                const unsigned int i) override;
     168             : 
     169             :   // Avoid hiding deprecated version with different signature
     170             :   using Elem::build_side_ptr;
     171             : 
     172             :   virtual void connectivity(const unsigned int sf,
     173             :                             const IOPackage iop,
     174             :                             std::vector<dof_id_type> & conn) const override;
     175             : 
     176             :   /**
     177             :    * \returns 2 for all \p n.
     178             :    */
     179       45382 :   virtual unsigned int n_second_order_adjacent_vertices (const unsigned int) const override
     180       45382 :   { return 2; }
     181             : 
     182             :   /**
     183             :    * \returns The element-local number of the  \f$ v^{th} \f$ vertex
     184             :    * that defines the \f$ n^{th} \f$ second-order node.
     185             :    *
     186             :    * \note \p n is counted as depicted above, \f$ 3 \le n < 6 \f$.
     187             :    */
     188             :   virtual unsigned short int second_order_adjacent_vertex (const unsigned int n,
     189             :                                                            const unsigned int v) const override;
     190             : 
     191             :   /**
     192             :    * \returns The child number \p c and element-local index \p v of the
     193             :    * \f$ n^{th} \f$ second-order node on the parent element.  See
     194             :    * elem.h for further details.
     195             :    */
     196             :   virtual std::pair<unsigned short int, unsigned short int>
     197             :   second_order_child_vertex (const unsigned int n) const override;
     198             : 
     199             :   /**
     200             :    * Geometric constants for Tri6.
     201             :    */
     202             :   static const int num_nodes = 6;
     203             :   static const int nodes_per_side = 3;
     204             : 
     205             :   /**
     206             :    * This maps the \f$ j^{th} \f$ node of the \f$ i^{th} \f$ side to
     207             :    * element node numbers.  It is derived from the first-order
     208             :    * Tri3 tables; see fe_reference_element_traits.h.
     209             :    */
     210             :   static constexpr NodeMapTable<num_sides, nodes_per_side>
     211             :   _side_nodes = derived_side_nodes<Tri3, num_sides>();
     212             :   static constexpr const unsigned int (&side_nodes_map)[num_sides][nodes_per_side] = _side_nodes.values;
     213             : 
     214             :   /**
     215             :    * An optimized method for approximating the area of a
     216             :    * TRI6 using quadrature.
     217             :    */
     218             :   virtual Real volume () const override;
     219             : 
     220             :   /**
     221             :    * \returns A bounding box (not necessarily the minimal bounding box)
     222             :    * containing the geometric element.
     223             :    */
     224             :   virtual BoundingBox loose_bounding_box () const override;
     225             : 
     226             :   virtual void permute(unsigned int perm_num) override final;
     227             : 
     228             :   virtual void flip(BoundaryInfo *) override final;
     229             : 
     230             :   unsigned int center_node_on_side(const unsigned short side) const override final;
     231             : 
     232             :   ElemType side_type (const unsigned int s) const override final;
     233             : 
     234             : protected:
     235             : 
     236             :   /**
     237             :    * Data for links to nodes.
     238             :    */
     239             :   Node * _nodelinks_data[num_nodes];
     240             : 
     241             : 
     242             : 
     243             : #ifdef LIBMESH_ENABLE_AMR
     244             : 
     245             :   /**
     246             :    * Matrix used to create the elements children.
     247             :    */
     248     6560786 :   virtual Real embedding_matrix (const unsigned int i,
     249             :                                  const unsigned int j,
     250             :                                  const unsigned int k) const override
     251     6560786 :   { return _embedding_matrix[i][j][k]; }
     252             : 
     253             :   /**
     254             :    * Matrix that computes new nodal locations/solution values
     255             :    * from current nodes/solution.
     256             :    */
     257             :   static const Real _embedding_matrix[num_children][num_nodes][num_nodes];
     258             : 
     259    10483728 :   LIBMESH_ENABLE_TOPOLOGY_CACHES;
     260             : 
     261             : #endif // LIBMESH_ENABLE_AMR
     262             : 
     263             : private:
     264             : 
     265             :   /**
     266             :    * Matrix that tells which vertices define the location
     267             :    * of mid-side (or second-order) nodes
     268             :    */
     269             :   static const unsigned short int _second_order_adjacent_vertices[num_sides][2];
     270             : 
     271             :   /**
     272             :    * Vector that names a child sharing each second order node.
     273             :    */
     274             :   static const unsigned short int _second_order_vertex_child_number[num_nodes];
     275             : 
     276             :   /**
     277             :    * Vector that names the child vertex index for each second order node.
     278             :    */
     279             :   static const unsigned short int _second_order_vertex_child_index[num_nodes];
     280             : };
     281             : 
     282             : 
     283             : } // namespace libMesh
     284             : 
     285             : #endif // LIBMESH_FACE_TRI6_H