How to run a topology optimization with a demold constraint

Question:

How do I setup my topology optimization to use the demold constraint?

Applies to:

  • Topology Optimization
  • Demold Constraint

Answer:

The Demold Constraint (Beta) block ensures the manufacturability of the final results for castings or plastic injection molding parts. The block prevents overhangs or undercuts based on a defined Demold direction. You can use this block for a single draw, a split draw with a variable surface, or a split draw with a known surface.

This article covers the three possible setups for using the Demold Constraint (Beta) block. All of the examples below use the same starting body (shown below), but they require different setups depending on the molding style. The Demold Constraint (Beta) block can significantly increase the solve time of the optimization so we recommend starting with a coarser mesh. 

Starting Body Demold Constraint.jpg

 

Single Draw:

For a single draw mold, the following parameters should be used:

  • Define the Demold Direction
  • Uncheck the Auto Split Surface
  • Do not define a region

Single_Draw_Example.jpg

 

Split Draw Variable Surface:

For a variable surface split draw mold, the following parameters should be used:

  • Define the Demold Direction
  • Check the Auto Split Surface
  • If you don’t want the constraint to be applied to the entire design space, specify a region

Split_Draw_Variable_Surface_Example.jpg

 

Split Draw Known Surface:

For a known surface split draw mold, the following parameters should be used:

  • Use 2 Demold Constraint (Beta) blocks, 1 for each half of the body
  • Uncheck the Auto Split Surface
  • Separate the design space using a parting surface (Region by Body block or similar)

The green semi-transparent body in the image below shows the right side of the body that is selected in the region input.

Split_Draw_Known_Surface_Example.jpg

And that’s it! You’ve successfully implemented the Demold Constraint (Beta) block. 

Are you still having issues? Contact the support team, and we’ll be happy to help!

Download the Example File:

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Keywords:

 surface topopt mold topology optimization constraint split single known draw molding demold 
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