Cyclic Symmetric

Use the Cyclic Symmetric tool on the Structure ribbon to apply cyclic symmetric repetition to a design space.

Cyclic symmetric repetitions are valid for optimization but not analysis.

You can generate cyclically repeating shapes like starfish, propellers, or spoked wheels even if you use a design space or loads that are not cyclic themselves. There are two kinds of cyclic shapes: those with symmetric sectors and those with asymmetric sectors. The Cyclic Symmetric tool is used to create symmetric sectors, as shown below. (Use the Cyclic tool to create asymmetric sectors.)

Figure 1. Cyclic repetition with symmetry. Cyclic repetition with symmetry creates self-symmetric sectors that are symmetric about the red radial planes. The red shaded area is a single sector.

To enforce cyclic symmetric repetition on a design space, you specify a center line and the number of repetitions to create within a 360 revolution. Red edges appear on cyclic repetition planes to indicate symmetric sectors and black edges to indicate asymmetric sectors, as shown above. You won't usually generate perfectly cyclic shapes, but you will get nearly cyclic shapes.

Take note not to confuse the Cyclic Symmetric tool with the Symmetric tool. The latter forces an entire design space to be symmetric about a plane, while cyclic symmetric repetition forces each individual sector within a cyclic design space to be self-symmetric about the red radial planes, as illustrated above. You are prevented from applying a cyclic constraint and a symmetric constraint simultaneously to one design space.

Apply Cyclic Symmetric Repetition

Select a design space and the number of cyclic symmetric sectors.

  1. On the Structures ribbon, select the Symmetric tool on the Shape Controls icon.

  2. Click the Cyclic Symmetric tool on the secondary ribbon.

  3. If you selected a design space before invoking the tool, cyclic symmetric repetitions are automatically applied to that design space. Otherwise, click on a design space to apply a cyclic symmetric constraint.
    A microdialog and a set of three red radial planes appear.
  4. Specify the number of Sectors in the text field of the microdialog.

  5. Right-click and mouse through the check mark to exit, or double-right-click.

Microdialog Options

Double-click a shape control to edit it and access the microdialog options.

Icon Description
Apply Symmetry and Cyclic Repetition Click to convert to a different type of shape control.
Sectors Enter the number of cyclic symmetric sectors.
Translate or rotate the shape control.
Align the radial planes to the global x, y, or z direction.
Align a shape control to a design space after moving it. By default, the radial planes are positioned and aligned to capture the natural shape and orientation of the design space, however it is oriented in space.
Click to manually enter the x, y, z components of the direction vector.