Topology Optimization with Level Set Method

Rahul_P1

Hello,

The user guide says that a new algorithm for topology optimization is now implemented in OptiStruct called the level set method.

It sounds really interesting and I am curious to use it but I wonder, how does it work? Does OptiStruct decide for its own which algorithm to choose or do I have to manually set it up in some control card? Does work together with SIMP or is it more like a stand alone algorithm?

Are there special features one needs to consider when using the level set method?

Thank you and have a nice day
Hawk

Rahul_P1

Hi Hawk,

To use the LEVEL SET method, you will need to mention this option in the DTPL card,

When you are pre processing for a topology optimization, you will be creating a DTPL card (the options entered from the topology panel will be entered into a card called DTPL)

you will need to open your optistruct input deck using a text editor, and add a continuation line with the LEVELSET keyword,

please see an example in the image in the below post

Please also see the DTPL documentation, Altair OptiStruct > Reference Guide > Input Data > Bulk Data Section > DTPL

Rahul_P1

image below -

Altair Forum User

Hi,

 

how can I use the modified Input deck then?

is it right to export the solver deck first, then add the keyword to the file and import it again?

I think i found the right place to add the LEVELSET keyword. but in my case this did not work. when i checked the generated .fem-file after the optimization the added keyword wasn't there..

can you help?

 

thanks a lot!

Rahul_P1

You should ideally export > edit the deck > then solve. 

Altair Forum User

Are any of these optimization methods (SIMP, LEVELSET) work with transient response?

 

Does optistruct use Evolutionary Structural Optimization? 

Altair Forum User

Are there any news about how the Level Set Method is implemented. What are the supposed advantages using LS?

For me it seems like Optistruct does kind of a remesh of the geometry, at least when im using quads, but not when using tets. Is this true? if yes, why is there a difference in the behavior for using different kind of meshing?

 

Hope someone has an idea

Altair Forum User

Hi Flad,

 

The phis are converted to densities thru a projection.

-          Design variables are nodal phis

-          Nodal phis are aggregated into element phis

-          Element phis are converted into element densities thru the projection.

 

The projection function used is Heaviside step function. It is a standard smooth function. You can find more info online.

 

On a side note, there is no development happening on LEVELSET method.