3 \page adding_quadratic_elements_page Adding Quadratic Elements
5 \n MESH module allows you to work with <b>Quadratic Elements</b>.
7 Quadratic elements are defined by same corner nodes as the
8 corresponding linear ones, and in addition they bear \a midside nodes
9 located between the corner nodes on element sides.
11 The quadratic quadrilateral element can bear an additional node at the
12 element center, then it is referred as bi-quadratic one (or
13 QUAD9). The quadratic hexahedral element can bear 7 additional nodes:
14 at the element center and at centers of sides, then it is referred as
15 tri-quadratic one (or HEXA27).
17 SALOME uses the convention of nodal connectivity of elements of MED library. You
18 can consult description of the nodal connectivity of elements located
19 within documentation on MED library or
20 <a href="http://www.code-aster.org/outils/med/html/connectivites.html">
23 There are several ways you can create quadratic elements in your mesh:
24 - manually create quadratic elements (the way described below);
25 - use \ref quadratic_mesh_anchor "Quadratic Mesh" hypothesis to
26 generate quadratic mesh on your geometry;
27 - convert an existing linear mesh to a quadratic one
28 (see \ref convert_to_from_quadratic_mesh_page).
30 <em>To add a quadratic element to your mesh:</em>
32 <li>Select your mesh in the Object Browser or in the 3D viewer.</li>
34 <li>From the \b Modification menu choose the \b Add item and select
37 \image html image152.png
39 \note All dialogs for quadratic element adding to the mesh
40 provide the possibility to automatically add an element
41 to the specified group or to create the group anew using
42 <b>Add to group</b> box, that allows choosing an existing group for
43 the created node or element or giving the name to a new group. By
44 default, the <b>Add to group</b> check box is switched off. If the user
45 swiches this check box on, the combo box listing all currently
46 existing groups of the corresponding type becomes available. By
47 default, no group is selected. In this case, when the user presses
48 <b>Apply</b> or <b>Apply & Close</b> button, the warning message box
49 informs the user about the necessity to input a new group name. The
50 combo box lists both \ref standalone_group "standalone groups"
51 and \ref group_on_geom "groups on geometry". If the user chooses a
52 group on geometry, he is warned and proposed to
53 \ref convert_to_standalone "convert this group to standalone".
54 If the user rejects conversion operation, it is cancelled and
55 a new quadratic element is not created.
58 To create any <b>Quadratic Element</b> specify the nodes which will form your
59 triangle by selecting them in the 3D viewer with pressed Shift
60 button. Their numbers will appear in the dialog box as <b>Corner Nodes</b>
61 (alternatively you can just input numbers in this field without
62 selection).The edges formed by the corner nodes will appear in the
63 table. To define the middle nodes for each edge double-click on the
64 respective field and input the number of the node. All edges and the
65 object formed by them will be displayed in the Object browser. When
66 all edges are defined you will be able to click \b Apply or <b>Apply and Close</b> button to
67 add the element to the mesh.
71 \b Reverse button for Quadratic Edges switches the first and the last
72 nodes. For all other elements it reverses the element.
