/*! \page double_nodes_page Duplicate Nodes or/and Elements \n This operation allows duplicating mesh nodes or/and elements, which can be useful to emulate a crack in the model. Duplication consists in creation of mesh elements "equal" to existing ones. To duplicate nodes or/and elements:
  1. From the \b Modification menu choose \b Transformation -> Duplicate Nodes or/and Elements item or click "Duplicate Nodes or/and Elements" button in the toolbar.
    \image html duplicate_nodes.png "Duplicate Nodes or/and Elements button"
  2. Check in the dialog box one of four radio buttons corresponding to the type of duplication operation you would like to perform.
  3. Fill the other fields available in the dialog box (depending on the chosen operation mode).
  4. Click the \b Apply or Apply and Close button to perform the operation of duplication.
\n "Duplicate Nodes or/and Elements" dialog has four working modes:
\anchor mode_without_elem_anchor

Duplicate nodes only

\image html duplicate01.png Parameters to be defined in this mode: A schema below illustrates how the crack is emulated using the node duplication. \image html crack_emulation_double_nodes.png "Crack emulation" This schema shows a virtual crack in a 2D mesh created using this duplication mode: - Black balls are duplicated nodes. - Red balls are new nodes. - Elements to replace nodes with new ones are marked with green. Note that in the reality duplicated nodes coincide with new nodes.
\anchor mode_with_elem_anchor

Duplicate nodes and border elements

\image html duplicate02.png Parameters to be defined in this mode: A schema below explains the crack emulation using the node duplication with border elements. \image html crack_emulation_double_nodes_with_elems.png "Crack emulation" This schema shows a virtual crack in a 2D mesh created using this duplication mode. In this schema: - Black segments are duplicated elements (edges in 2D case). - Black balls (except for the lowest one) are duplicated nodes of duplicated elements. - The lowest black ball is the non-duplicated node. - Red balls are newly created nodes. - Red segments are created elements (edges). - Elements to replace nodes with new ones are marked with green. Note that in the reality nodes to duplicate coincide with new nodes.
In a 3D case, where elements to duplicate are faces, the edges located at the "crack" (if any) are cloned automatically.
\anchor mode_elem_only_anchor

Duplicate elements only

This mode duplicates the given elements, i.e. creates new elements with the same nodes as the given elements.
\image html duplicate03.png Parameters to be defined in this mode:
\anchor mode_group_boundary_anchor

Duplicate nodes on group boundaries

This mode duplicates nodes located on boundaries between given groups of volumes.
\image html duplicate04.png Parameters to be defined in this mode:
See Also a sample TUI Script of a \ref tui_duplicate_nodes "Duplicate nodes or/and elements" operation. */