Circular pattern grouping allows you to force OptiStruct to create beads that form concentric circles around a user-defined axis. This can be very useful for optimizing the shape of circular parts that must have a circular reinforcement pattern such as a part turned on a lathe.

For circular pattern grouping (TYP = 2 or 12), OptiStruct generates shape variables that form circles about an axis defined by the first vector. These circular beads have a width equal to the minimum bead width parameter. The anchor point can be located anywhere, but the first vector must be collinear with the desired central axis for the circular beads. The simple circular pattern grouping (TYP = 2):

TYP = 2: Circular pattern grouping

For one plane circular pattern grouping (TYP = 12), the circular patterns are reflected about a plane located at the anchor node and defined by the first vector. One plane circular symmetry ensures that nodes equal distances above and below the plane of symmetry will be grouped into the same variables.

TYP = 12: One plane circular symmetry