Connect mesh of design and non-design space

Hi all,

I'm doing a topology optimization to wheel spokes and my model consists of a big disk with the contour and the area where the lug nuts apply (image attached). As I only want to optimize the spokes the green area must be the design space. I can connect it with the purple area but i cant connect it with the yellow one. The contour geometry (yellow part) is also attached.

I tried to import the model from solidworks as a single part and cant split in hypermesh the spokes from the contour. I have also imported as 2 sepparate parts and when meshing problems appear and can't mesh it properly.

Regards,

Rodrigo

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HyperMesh

OptiStruct

v2019.1

Accepted answers

QuyNguyenDai

Before meshing, try to merge two solids: Geom -> Solid edit -> Merge or Boolean operation.

By this way, your two solids share the same surface and the mesh will be continuous from one solid to other.

All comments

QuyNguyenDai

So you have some issue with Hypermesh, not Optistruct, right?

Show us your mesh to better understand why you "can't mesh properly" ?

Adriano Koga_20259

Rodrigo,

If you take the whole solid and then split it in HM, and mesh it, it should be all connected.

But if you bring the solid in parts from CAD, your geometries will be disconnected thus your mesh also will be disconnected.

Even so, you can simply connect them through a FREEZE contact, so that they will not have relative displacements relative to each other.

It is not the best option, but it will do the job.

RodrigoFST_22268

Yeah, the issue is with creating the mesh in Hypermesh. The solver to be used after the issue is solved is Optistruct. I'll attach an image showing the unconnected mesh (under the blue line the elements are connected and under the red are disconnected) if all three components are meshed together with the option of mesh connectivity on.

I'm using volume tetra option of the tetramesh menu.

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RodrigoFST_22268

Rodrigo,

If you take the whole solid and then split it in HM, and mesh it, it should be all connected.

But if you bring the solid in parts from CAD, your geometries will be disconnected thus your mesh also will be disconnected.

Even so, you can simply connect them through a FREEZE contact, so that they will not have relative displacements relative to each other.

It is not the best option, but it will do the job.

I tried to do that but the geometry of the contour makes it impossible to split from the center with the hypermesh tools (at least that I know of). In the attached image shows how they should be split. Thanks for the help.

6.PNG

RodrigoFST_22268

So you have some issue with Hypermesh, not Optistruct, right?

Show us your mesh to better understand why you "can't mesh properly" ?

Sorry, I've repplied in the general post instead of here. Still adapting to this new layout. Thank you for your help.

Adriano Koga_20259

I tried to do that but the geometry of the contour makes it impossible to split from the center with the hypermesh tools (at least that I know of). In the attached image shows how they should be split. Thanks for the help.

Ok.

But again, if you want, you could use FREEZE contact and just tie everything together. It would solve your mesh discontinuities.

QuyNguyenDai

Before meshing, try to merge two solids: Geom -> Solid edit -> Merge or Boolean operation.

By this way, your two solids share the same surface and the mesh will be continuous from one solid to other.

RodrigoFST_22268

Ok.

But again, if you want, you could use FREEZE contact and just tie everything together. It would solve your mesh discontinuities.

Yeah, I can do that. Just wanted to know if there was a simple way of solving this.

RodrigoFST_22268

Before meshing, try to merge two solids: Geom -> Solid edit -> Merge or Boolean operation.

By this way, your two solids share the same surface and the mesh will be continuous from one solid to other.

When I try to merge HM says none of the 2 selected solids share surfs. However the advanced boolean that keeps all parts and combines through AB faces in B works! The mesh is perfectly connected. Thanks a lot!!

priya saxena

Before meshing, try to merge two solids: Geom -> Solid edit -> Merge or Boolean operation.

By this way, your two solids share the same surface and the mesh will be continuous from one solid to other.

can we merge the two seperate meshes which are build in two different mesh files if the geometry is complex ?