About Tightness Restriction for the Resulting Structure

The manufacturing constraints for tightness represent a possibility to prevent the remaining structure from having holes and breakouts in the defined restriction area.

Related Topics
Defining a Tightness Restriction
About Prevention of Undercuts in the Model

The following figure shows an example with check type CAST (left) in comparison to check type AUTO_TIGHT (right):

The elements are removed in a similar way to the option AUTO. This means that the elements are removed in the pull direction or in the opposite direction. However, at least one layer of elements will be present in the middle plane. The resulting "middle plane" is not necessarily planar. It might be a curved surface.

The tightness is only checked within the restriction area. It is not possible to ensure a tight connection to elements outside the restriction group in the area of the boundary.

The midplane thickness is controlled by the RADIUS parameter (midplane thickness = 2*RADIUS).

Important:
  • For 2D models, the definition of a manufacturing constraint leads to a significant reduction of the possible solution space. If this option is used in combination with 2D models, an additional definition for the step width should be added using the OPT_PARAM command (the parameter SPEED=SLOW has to be defined).
  • Breakouts might occur if there are thin walls parallel to the pull direction. These areas should be excluded from the restriction group.