About Rib Design

The rib restriction gives the user the possibility to obtain optimization results that contain rib patterns.

The rib pattern restriction forces the optimizer to prevent material accumulation and generate substructures in the form of ribs. The thickness of the individual ribs and the distances between ribs are averaged over the design area and can be controlled in the restriction definition. The direction of the ribs is here defined as the out-of-plane growth direction of the ribs. The rib height may depend on the design domain when the full height is used, otherwise a variable rib height may be defined. This should be taken into account when defining an additional volume/weight constraint.

The following figure shows the quantities that need to be defined for a rib restriction:

Rib Height

Tosca Structure enables the control of the rib height in each rib restriction using the RIB_HEIGHT command item. As shown in the figure below, MAX uses the full height of the designspace and MIN defines a minimum rib height with the actual rib height varying between this value and the full design space height. When variable rib height without a minimum rib height, it can be achieved by choosing the MIN option with a value of 0. In case, the MIN value set is larger that the model dimension in rib direction, one obtains the same results as with MAX.