Extruding Mesh Parts by Rotation

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

You will see here how to:

Create a 2D mesh from a 1D mesh

Open the Sample21.CATAnalysis document from the samples directory.

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

    The Extrusion with Rotation 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
      • Axis: lets you specify the axis of extrusion by rotation.
      • Start: lets you specify the start angle value of the extrusion (in deg).
      • End: lets you specify the end angle value of the extrusion (in deg).

        You can enter a negative value in the Start and End fields.
    • 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.

        Note that the mesh size is variable and depends on this value and the distance between the source node and the axis of extrusion by rotation.
        For example, if the distribution is uniform, the extrusion radius value between the source node and the axis of extrusion by rotation is 40mm, the angle is 45deg and the Layers number value is 10, the mesh size value will be :
        (Angle* Radius) / Layers number = ((PI/4) * 40mm) / 10 = 3.14 mm
      • 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 Rotation dialog box.

    In this particular example:

    1. Select Line.1 as Axis as shown below:

      Note that as soon as you selected the axis, a red arrow appears.
      This arrow indicates the reference direction of the extrusion.

    2. Enter 0deg as Start value.

    3. Enter 120deg as End value.

    4. Select Uniform as Type option.

    5. Enter 12 as Layers number value.

  4. Click Apply.

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

  5. Change the following parameters:

    1. Enter 70deg as End value.

    2. Select Arithmetic as Distribution Type option.

    3. Enter 10 as Layers number value.

    4. Enter 5 as Size ratio value.

  6. Click Apply and then OK.

    As a result the 2D extrusion by rotation 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 Sample21_1.CATAnalysis document from the samples directory.

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

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

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

    In this particular example, select the Extrusion Mesh with Rotation.1 mesh part in the specification tree.

  3. Set the desired parameters.

    In this particular case:

    1. Select Line.2 as Axis as shown below:

      Note that as soon as you selected the axis, a red arrow appears.
      This arrow indicates the reference direction of the extrusion.

    2. Enter 0deg as Start value.

    3. Enter 120deg as End value.

    4. Select Uniform as Type option.

    5. Enter 10 as Layers number value.

  4. Click Apply.

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

  5. Change the following parameters:

    1. Enter -150deg as End value.

    2. Select Geometric as Distribution Type option.

    3. Enter 10 as Layers number value.

    4. Enter 4 as Size ratio value.

    5. Select the Symmetry check box.

  6. Click Apply and then OK.

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