/*! \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. <em>To duplicate nodes or/and elements:</em> <ol> <li>From the \b Modification menu choose \b Transformation -> <b> Duplicate Nodes or/and Elements </b> item or click <em>"Duplicate Nodes or/and Elements"</em> button in the toolbar. <br> \image html duplicate_nodes.png "Duplicate Nodes or/and Elements button" </li> <li>Check in the dialog box one of four radio buttons corresponding to the type of duplication operation you would like to perform.</li> <li>Fill the other fields available in the dialog box (depending on the chosen operation mode).</li> <li>Click the \b Apply or <b>Apply and Close</b> button to perform the operation of duplication.</li> </ol> \n "Duplicate Nodes or/and Elements" dialog has four working modes: <ul> <li>\ref mode_without_elem_anchor "Duplicate nodes only"</li> <li>\ref mode_with_elem_anchor "Duplicate nodes and border elements"</li> <li>\ref mode_elem_only_anchor "Duplicate elements only"</li> <li>\ref mode_group_boundary_anchor "Duplicate nodes on group boundaries"</li> </ul> <br> \anchor mode_without_elem_anchor <h2>Duplicate nodes only</h2> \image html duplicate01.png Parameters to be defined in this mode: <ul> <li><b>Group of nodes to duplicate</b> (<em>mandatory</em>): these nodes will be duplicated.</li> <li><b>Group of elements to replace nodes with new ones</b> (<em>optional</em>): the new nodes will replace the duplicated nodes within these elements.</li> <li><b>Construct group with newly created nodes</b> option (<em>checked by default</em>): if checked - the group with newly created nodes will be built.</li> </ul> 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 <b>duplicated nodes</b>. - Red balls are <b>new nodes</b>. - <b>Elements to replace nodes with new ones</b> are marked with green. Note that in the reality <b>duplicated nodes</b> coincide with <b>new nodes</b>. <br> \anchor mode_with_elem_anchor <h2>Duplicate nodes and border elements</h2> \image html duplicate02.png Parameters to be defined in this mode: <ul> <li><b>Group of elements to duplicate</b> (<em>mandatory</em>): these elements will be duplicated.</li> <li><b>Group of nodes not to duplicate</b> (<em>optional</em>): group of nodes at crack bottom which will not be duplicated.</li> <li><b>Group of elements to replace nodes with new ones</b> (<em>mandatory</em>): the new nodes will replace the nodes to duplicate within these elements.</li> <li><b>Construct group with newly created elements</b> option (<em>checked by default</em>): if checked - the group of newly created elements will be built.</li> <li><b>Construct group with newly created nodes</b> option (<em>checked by default</em>): if checked - the group of newly created nodes will be built.</li> </ul> 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 <b>duplicated elements</b> (edges in 2D case). - Black balls (except for the lowest one) are duplicated nodes of <b>duplicated elements</b>. - The lowest black ball is the <b>non-duplicated node</b>. - Red balls are <b>newly created nodes</b>. - Red segments are <b>created elements</b> (edges). - <b>Elements to replace nodes with new ones</b> are marked with green. Note that in the reality <b>nodes to duplicate</b> coincide with <b>new nodes</b>. <br> In a 3D case, where <b>elements to duplicate</b> are faces, the edges located at the "crack" (if any) are cloned automatically. <br> \anchor mode_elem_only_anchor <h2>Duplicate elements only</h2> This mode duplicates the given elements, i.e. creates new elements with the same nodes as the given elements. <br> \image html duplicate03.png Parameters to be defined in this mode: <ul> <li><b>Group of elements to duplicate</b> (<em>mandatory</em>): these elements will be duplicated.</li> <li><b>Construct group with newly created elements</b> option (<em>checked by default</em>): if checked - the group of newly created elements will be built. The name of the created group starts from "DoubleElements".</li> </ul> <br> \anchor mode_group_boundary_anchor <h2>Duplicate nodes on group boundaries</h2> This mode duplicates nodes located on boundaries between given groups of volumes. <br> \image html duplicate04.png Parameters to be defined in this mode: <ul> <li><b>Groups (faces or volumes) </b> (<em>mandatory</em>): list of mesh groups. These groups should be disjoint, i.e. should not have shared elements.</li> <li> If <b>Create joint elements</b> option is activated, flat elements are created on the duplicated nodes: a triangular facet shared by two volumes of two groups generates a flat prism, a quadrangular facet generates a flat hexahedron. Correspondingly 2D joint elements (null area faces) are generated where edges are shared by two faces. <br> The created flat volumes (or faces) are stored in groups. These groups are named according to the position of the group in the list of groups: group "j_n_p" is a group of flat elements that are built between the group \#n and the group \#p in the group list. All flat elements are gathered into the group named "joints3D" (correspondingly "joints2D"). The flat elements of multiple junctions between the simple junction are stored in a group named "jointsMultiples".</li> <li> If <b>On all boundaries</b> option is activated, the volumes (or faces), which are not included into <b>Groups</b> input, are considered as another group and thus the nodes on the boundary between <b>Groups</b> and the remaining mesh are also duplicated.</li> </ul> <br><b>See Also</b> a sample TUI Script of a \ref tui_duplicate_nodes "Duplicate nodes or/and elements" operation. */