X-Git-Url: http://git.salome-platform.org/gitweb/?p=modules%2Fsmesh.git;a=blobdiff_plain;f=doc%2Fsalome%2Fgui%2FSMESH%2Finput%2Fadding_quadratic_elements.doc;h=2fd906bafbde6abd91d248ca97f7e08ce7be0a9f;hp=50d8eafb1541a8de5fa10886788b744e3c30d696;hb=23d90107acec5e54ded86d9f309fe5cb42720b78;hpb=79b1ac2b6df9117f16f11d444b1f165d477a1813 diff --git a/doc/salome/gui/SMESH/input/adding_quadratic_elements.doc b/doc/salome/gui/SMESH/input/adding_quadratic_elements.doc index 50d8eafb1..2fd906baf 100644 --- a/doc/salome/gui/SMESH/input/adding_quadratic_elements.doc +++ b/doc/salome/gui/SMESH/input/adding_quadratic_elements.doc @@ -2,12 +2,30 @@ \page adding_quadratic_elements_page Adding Quadratic Elements -\n MESH modules allows you to work with Quadratic Elements. +\n MESH module allows you to work with Quadratic Elements. -Quadratic Edge is not a straight but a broken line and can be defined -by three points: first, middle and last. All more complex \b Quadratic -\b Elements differ from ordinary ones in that they consist of Quadratic -Edges. +Quadratic elements are defined by the same corner nodes as the +corresponding linear ones, but in addition they have \a midside nodes +located between the corner nodes on element sides. + +If a quadratic 2D element has an additional node at the +element center, it is a bi-quadratic element (both TRIA7 and +QUAD9 elements are supported). If a quadratic hexahedral element has 7 +additional nodes: at the element center and at the center of each +side, it is a tri-quadratic element (or HEXA27). + +The convention of nodal connectivity of elements used in SALOME is +the MED library convention. You can consult the description of nodal +connectivity of elements in the documentation on MED library or + + here . + +There are several ways to create quadratic elements in your mesh: +- manually (this way is described below); +- use \ref quadratic_mesh_anchor "Quadratic Mesh" hypothesis to +generate a quadratic mesh on your geometry; +- convert an existing linear mesh to a quadratic one +(see \ref convert_to_from_quadratic_mesh_page). To add a quadratic element to your mesh:
    @@ -16,23 +34,50 @@ Edges.
  1. From the \b Modification menu choose the \b Add item and select one of the following: -\image html image152.gif - -To create any Quadratic Element specify the nodes which will form your -triangle by selecting them in the 3D viewer with pressed Shift -button. Their numbers will appear in the dialog box as Corner Nodes -(alternatively you can just input numbers in this field without -selection).The edges formed by the corner nodes will appear in the -table. To define the middle nodes for each edge double-click on the -respective field and input the number of the node. All edges and the -object formed by them will be displayed in the Object browser. When -all edges are defined you will be able to click \b OK or \b Apply button to +\image html image152.png + +\note All dialogs for adding quadratic element to the mesh +provide the possibility to automatically add an element +to the specified group or to create the group anew using +Add to group box, that allows choosing an existing group for +the created node or element or giving the name to a new group. By +default, the Add to group check box is switched off. If the user +swiches this check box on, the combo box listing all currently +existing groups of the corresponding type becomes available. By +default, no group is selected. In this case, when the user presses +Apply or Apply & Close button, the warning message box +informs the user about the necessity to input a new group name. The +combo box lists groups of all the +\ref grouping_elements_page "three types": both +\ref standalone_group "standalone groups", +\ref group_on_filter "groups on filter", and +\ref group_on_geom "groups on geometry". If the user chooses a +group on geometry or on filter, he is warned and proposed to +convert this group to standalone. +If the user rejects conversion operation, it is cancelled and +a new quadratic element is not created. + + +To create any Quadratic Element specify the nodes which will +form your element by selecting them in the 3D viewer with pressed +Shift button and click \a Selection button to the right of +Corner Nodes label. Their numbers will appear in the dialog box +as Corner Nodes (alternatively you can just input numbers in +this field without selection; note that to use this way the mesh +should be selected before invoking this operation). The edges formed +by the corner nodes will appear in the table. To define the middle +nodes for each edge, double-click on the respective field and input +the number of the node (or pick the node in the viewer). For +bi-quadratic and tri-quadratic elements, your also need to specify +central nodes. +As soon as all needed nodes are specified, a preview of a new +quadratic element will be displayed in the 3D viewer. Then +you will be able to click \b Apply or Apply and Close button to add the element to the mesh. \image html aqt.png -\b Reverse button for Quadratic Edges switches the first and the last -nodes. For all other elements it reverses the element. +\b Reverse button reverses the element.