Separate Design and Nondesign Space in OptiStruct

Altair Forum User

Dear Mr. Grasmannsdorf,

I have a question regarding topology optimization in OptiStruct, where the optimization parameters is defined in HyperMesh. Is it possible to define an area in the design space where no material should be taken away during the topology optimization? Please find a simple example in the picture below.



Kind Regards,
Linn Lemón

Rahul Rajan_21763

you can put those region in to non design area.Picture is missing.

Altair Forum User

Dear Linn,

 I did not find the attachment in your mail, but I guess I understood the question.

To separate Design and Nondesign Space, you must create two different components with different Properties (PSOLID) in HyperMesh. You can then use the 'Mesh - organize' menu to move your elements to the correct Nondesign or Design component.

Within the menu “Optimization – create - Topology Desvar “ you will then select / assign  only the “design” property to be part of your optimization. All unmarked properties and connected components will remain during optimization.

See the following tutorial and look carefully at step 2 & step 7 to see how it is done.

 Best Regards

 Jan

Altair Forum User

Thanks for the your answer, and sorry that the picture didn´t follow. It should be in this message. In that example, the plate in the middle has one property and is assigned to be the design space and the other two plates the non-design space. However, would it be possible to prevent some region in the design space (the plate in the middle) not to be affected by the optimization? Or do I have to define a new region and assign them another property in order to separate it from the design space? 

Which tutorial did you mean?

Thanks, Linn

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Rahul Rajan_21763

Looks like you have assembly where three parts are connected via connector.We would recommend you to take only central part for optimization & consider all load acting from adjacent part.Then region near to bolts (circular area)you can make it as non design area.

Altair Forum User

I'm not quite sure how you mean, could you please explain it a bit further? 

Different load cases will be applied to the two plates that belongs to the non-design space in the picture, this is to see how it will affect the connected plate in the middle and optimize that plates design. 

When you say that I can make the area near the bolts a non-design area, is that possible to do when I set up the optimization in HyperMesh, or do I have to e.g. create a 'new component' around the bolts in order to assign it an other property compared to the design space?

Rahul Rajan_21763

Refer online tutorial of Optistruct.See attached screenshot.

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Altair Forum User

Dear Linn,

 

as you suggested, you will need to create a new component & Property and then organize your elements into this new component, to make the area a non-design space.

 Jan

Altair Forum User

Okay, thank you for your answer!