Objective:

Topology optimization in nTop Platform offers some manufacturing constraints. One of those is the overhang constraint for additive manufacturing. This article will discuss how to use the constraint and show the differences between a constrained and unconstrained example.

Applies to:

• nTop 2.24.5
• Topology Optimization
• Additive Manufacturing

Procedure:

1. As of nTop Platform 2.24.5, this function is a Beta feature, so go to File > Settings  and enable Show Beta Blocks
2. Add the Overhang Constraint block to your notebook by either of the following
   
   • On the ribbon, go to Beta and select Overhang Constraint from the Topology Optimization panel
   • Type Overhang Constraint into the search bar
3. Define the Build direction as a vector. This corresponds to the direction of manufacture. If your part is already oriented on the X-Y plane, then this will typically be the Z+ direction, which corresponds to a vector of <0,0,1>.  Tip: This is an ideal parameter to use in DoEs to explore the solution space fully.
4. Specify the max angle, which is the maximum allowable overhang angle allowed by the manufacturing process. 
5. Specify the support boundaries, which are the regions you want to allow support structures to be applied to.  Use the FE Boundary by Body or FE Boundary by Flood Fill or FE Face Boundary. The support boundaries must use face selection, so be sure to select that in the boundary block.
6. 
7. The Overhang Constraint can now be dragged into the Constraints list of an existing Topology Optimization.

Unconstrained results on the left, and results with an overhang constraint of 45 degrees on the right.

And that’s it! You’ve successfully used the overhang constraint for Topology Optimization. 

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

Download the Example file:

• GE Bracket

More on this Topic:

• Users' Guide to Topology Optimization in nTop Platform
• Topology Optimization: Settings