Hi everyone,

Abaqus/ATOM allows one to create geometric restrictions to ensure that the final topology can be manufactured using a certain manufacturing technique such as casting, forging. In this post I would like to throw some light on how to avoid formation of holes in the central plane for a demold control geometric restriction. Demold control geometric restriction ensures that the final topology can be demolded.

Let’s look at an example:

Controller based topology optimization of a cantilever beam:

Consider the example of a cantilever beam loaded at the tip with a 100 lb force as shown below.

Optimization definition:

Minimize (compliance)

Subject to: Vfinal=0.7*Vinitial

Demold control geometric restriction:

Here the demold control geometric restriction is defined on the whole model. During manufacturing the part will be pulled out of the mold in x direction. Note that the option 'Prevent hole formation' is selected. Let’s look at the results with and without this option.

Isometric view:

Front view:

Note that we recommend running the optimization for at least 15 design cycles while using controller based topology optimization. In this example we are looking at the results for design cycle 5.

For more details on geometric restrictions please refer section18.10.2 Creating a geometric restriction in a topology optimization of Abaqus/CAE Users Manual (release 6.11-1)