Extruding Mesh Parts by Symmetry

This task shows you how to extrude a mesh by symmetry.

You will see here how to:

Create a 2D mesh from a 1D mesh

Open the Sample24.CATAnalysis document from the samples directory.

  1. Click Extrude Mesher with Symmetry in the Mesh Transformations toolbar.

    The Extrusion with Symmetry dialog box appears.

    • Mesh Part: lets you specify the mesh part to extrude.

      Multi-selection of mesh parts is available.
      • Remove: lets you remove a selected mesh part from the Mesh Part field.
      • Remove all: lets you remove all the selected mesh parts from the Mesh Part field.
    • Transformation
      • Plane: lets you specify the plane of symmetry of the extrusion.
    • Distribution:
      • Type: lets you choose the node distribution type:
        • Uniform: the distance between all the distributed nodes will be the same.
        • Arithmetic: the distance between the distributed nodes will be defined by an arithmetical distribution.
        • Geometric: the distance between the distributed nodes will be defined by a geometrical distribution.
      • Layers number: lets you specify the number of layers you want.
        • The extrusion length is twice the distance between the source mesh and the plane of symmetry.
        • Note that this value determines the mesh size.
          For example, if the distribution is uniform, the extrusion Length value is 30mm and the Layers number value is 6, the mesh size value will be : 30mm / 6 = 5mm.
      • Size ratio: lets you specify the common difference value for an Arithmetic distribution or the common ratio value for a Geometric distribution.

        This option is only available if you selected Arithmetic or Geometric as Distribution Type option.
      • Symmetry: lets you specify if the distribution should be symmetric or not.

        This option is only available if you selected Arithmetic or Geometric as Distribution Type option.
    • Capture: a node capture is automatically done between the parent mesh part and the extruded mesh part.
      • Condensation: if selected, this option lets you condense nodes of the extruded mesh part and updated neighboring mesh parts using a tolerance value.
      • Tolerance: lets you specify the tolerance value of condensation (only available with the Condensation option).
      • Initialize: lets you automatically initialize the tolerance value of condensation if the Condensation check box is selected.
        The tolerance is initialized with the smallest size of element edges among all the loaded mesh parts.

        The tolerance initialization does not take into account 1D elements.
      • Check: this button is active as soon as you click the Apply button. This button lets you check, using the tolerance value, if there are intersections or interferences between the extruded mesh and the captured mesh parts (only available with the Condensation option).
        To know more, refer to Checking Intersections / Interferences.

  2. Select the 1D Mesh.1 mesh part in the specification tree.

  3. Set the desired parameters in the Extrusion with Symmetry dialog box.

    In this particular case:

    1. Select xy plane from the specification tree as Plane option as shown below:

    2. Select Uniform as Type option.

    3. Enter 5 as Layers number value.

  4. Click Apply.

    An Extrusion Mesh with Symmetry.1 object appears in the specification tree and a 2D extrusion by symmetry mesh part is created.

  5. Change the parameters in the Extrusion with Symmetry dialog box.

    In this particular example:

    1. Activate the Plane field and select yz plane in the specification tree.

    2. Select Geometric as Distribution Type option.

    3. Enter 5 as Layers number value.

    4. Enter 4 as Size ratio value.

  6. Click Apply and then OK.

    As a result the 2D extrusion by symmetry mesh part is updated as shown below:

 

Create a 3D mesh from a 2D mesh

Use the CATAnalysis document you have obtained at the end of the Create a 2D mesh from a 1D mesh scenario or open the Sample24_1.CATAnalysis document from the samples directory.

  1. Click Extrude Mesher with Symmetry in the Mesh Transformations toolbar.

    The Extrusion with Symmetry dialog box appears.
    To know more about the Extrusion with Symmetry dialog box, refer to Create a 2D mesh from a 1D mesh.

  2. Select the 2D mesh part you want to extrude.

    In this particular example, select the Extrusion Mesh with Symmetry.1 mesh part in the specification tree or directly from the viewer as shown below:

  3. Set the desired parameters in the Extrusion with Symmetry dialog box.

    In this particular case:

    1. Select xy plane from the specification tree as Plane option as shown below:

    2. Select Uniform as Distribution Type option.

    3. Enter 8 as Layers number value.

  4. Click Apply.

    An Extrusion Mesh with Symmetry.2 object appears in the specification tree and a 3D extrusion by symmetry mesh part is created.

  5. Change the parameters in the Extrusion with Symmetry dialog box.

    In this particular example:

    1. Select Arithmetic as Distribution Type option.

    2. Enter 5 as Layers number value.

    3. Enter 4 as Size ratio value.

    4. Select the Symmetry check box.

  6. Click Apply.

    As a result the 3D extrusion by symmetry mesh part is updated as shown below:

  7. Click OK.