How to apply draw direction constraint?

Baturalp OGUZ_20261

Hello,

I just started topology optimization with Optistruct, I was practicing about manufacturing constraints, but I don't know how to apply the draw direction constraint, I have already checked the tutorials but I did not understand. Specifically, what to choose the anchoring grid and first grid? does the choosing have an affect if the part will be produced with additive manufacturing (like chose the grids in accordance to build direction etc.)

Also, with an arbitrary model, i was trying to apply overhang, symmetric and draw direction constraints but an error message showed up, "overhang constraint and draw direction cannot be use in the same DTPL" is there any other way to do that? or this complately wrong in accordance to nature of topology optimization.

 

Thanks for taking time.

Viraj Kulkarni_21218

Here are some quick examples to understand the anchor and first grid.

Basically the anchor grid is the base node for the symmetry.

First grid for 1plane symmetry is used to find the direction of the normal to the symmetry plane.

You can check this link, to get more info

Combine Pattern Repetition and Pattern Grouping with other Manufacturing Constraints (altair.com)

Baturalp OGUZ_20261

I am okey with symmetric constraint, can you please explain how to apply draw direction? and why combination of draw and overhang constraints did fail?

I just tried 2 different DTPL with same property one of them is constrained with symmetric and draw constraints other one is constrained with overhang and symmetric constraint. Is it the correct solution for  combined topology optimization with 3 constraints?

Viraj Kulkarni_21218

Draw direction and overhang constraint cannot be combined on same DTPL card.

You can either combine draw with symmetry or overhang with symmetry

Single draw, split draw, extrusion and overhang belong to same group, you can pick only one.

For symmetry you can use either plane symmetries, cyclic or cyclic symmetries.

Here is a quick snapshot of draw direction, the logic is similar to the earlier, you use anchor node as base, then choose grid 1 to sow draw direction, basically you form a vector.

You can view these tutorials for more help too:

OS-T: 2060 Symmetry and Draw Direction Constraints Applied Simultaneously (altair.com)

OS-T: 2030 Control Arm with Draw Direction Constraints (altair.com)

More help: Topology Optimization Manufacturability (altair.com)

 

I also wanted to point out, you can use Altair Inspire for topology optimization as well. It uses OptiStruct solver in to solve the FEA.

It has user friendly GUI, which you might like

 

Baturalp OGUZ_20261

Thank you for your time! another question is that what about i wanted to use combination of several constraints? is it possible? like i can create 2 different DTPL and combine with symmetric constraint in both (overhang + symmetric) , (draw + symmetric) does the solution will give a reasonable geometry?