Automatically Generate Shapes

Use the Autoshape function to automatically generate multiple shapes for individual handles or domains.

This feature is intended for shape optimization and can be used to quickly generate many shapes to be used as shape variables. One suggested use is to create handles across the surface of a solid part and use Autoshape to generate well-behaved shapes for those handles moving normal to the surface of the part. OptiStruct can be used to optimize the surface shape of the part using these shapes. For linear shapes, a biasing factor of 2 is recommended.

  1. From the Morph ribbon, click the Shapes tool.
    Figure 1.


    The Edit Shapes dialog opens.
  2. Right-click in the Edit Shapes dialog and select Autoshape from the context menu.
  3. Select the type of shapes to create.
    OptionDescription
    Linear shapes Move the handle using the standard morphing procedure.
    Spline shapes Use a spline algorithm to smoothly apply the shape across the domain.
    Polynomial shapes Use a polynomial algorithm to smoothly apply the shape across the domain.
    Figure 2.


    Figure 2 shows autoshapes that been created for the handles along the left side of the mesh. In each example, one of the autoshapes has been applied. The standard shape in this case is angular but will be more curved if handle biasing is used (see Set Biasing). The spline shape creates a smooth shape that runs across the entire length of the edge domain as does the polynomial shape, but the spline shape is more controlled.
    Note: When all the spline or polynomial shapes for a given domain are applied, the resulting perturbations for the nodes along the domain sum to the same amount, so if your domain is flat when the shapes are unapplied, as shown in Figure 2, it will also be flat when the shapes are all applied by the same factor. You can create a Fourier-type series with smoothness ensured across the handles.
  4. Select handles, for linear shapes, or domains, for spline or polynomial shapes.
    Shapes will be created at the selected handles or at the handles lying on the selected domains.
  5. Select the direction the handles will be moved in when creating shapes.
    Choose the direction that the shape is applied in. For along element normals and along vector HyperMesh generates one shape for every selected handle in the direction normal to the surrounding shell elements at the given magnitude. For XYZ components, HyperMesh generates up to three shapes for every handle selected, based on the directions which you have checked.
    OptionDescription
    Along XYZ axes Figure 3 shows the preview vectors for the same six handles using XYZ components.
    Note: The Along XYZ axes option creates a shape in each of the selected directions at the given magnitudes. Therefore, if you select two handles and all three XYZ components, six shapes are generated, one in each of the X, Y, and Z directions for both handles.
    Figure 3. By XYZ


    Restriction: This option is only available when the type of shape is set to Linear shapes.
    Along vector

    Figure 4 shows the preview vectors for the same six handles using by vector. This option requires you to specify a vector by using the manipulator.

    Figure 4. Along Vector


    From the drop-down menu, choose use all elements or use selected elements.
    Along element normals Figure 4 shows the preview vectors for six handles using element normals.
    Figure 5. Along Normal


    From the drop-down menu, choose use all elements or use selected elements.
    Use shape Use shape option applies only to spline or polynomial types. You can use a shape to define the perturbation vectors for the handles. The selected shape may have been saved as node perturbations or handle perturbations. In either case, the shape will be converted to node perturbations and the perturbations found at the selected handles will be used.
    Restriction: This option is not supported for linear shapes.
  6. From the System drop-down menu, select Global or Local coordinate system depending on which corresponds to the X, Y, and Z directions.
    Restriction: This option is only available when the direction is set to Along XYZ axes.
  7. Choose whether to base the direction on the normals of all elements, or on only the normals of elements that you select from the element selector.
    Restriction: This option is only available when the direction is set to Along element normals.
    Handles usually touch more than one element and the average normal for those elements is used for the handle.
  8. Select the Preview check box to show the vectors at the handles where the shapes will be created.
  9. Click Create.