I have a student who struggled with the same problem. His conclusion was that converting the implicit geometry (ntopology) to an explicit CAD geometry (e.g. step) was too intrusive. The exported geometry deviated significantly from the lattice modeled in ntopology.

Finally he decided to work with meshes exported from ntopology and imported to ANSYS WB. I think he uses the ANSYS cdb format and he can easily apply boundary conditions and loads (but cannot edit the mesh in ANSYS).

Dear Konstantinos Poulios,

Thank you so much for your answer. yes, I think it is the only way to do. I am working on that to do the same.

Best, Mansoureh

Dear Dawit Alemayehu

Good luck and enjoy working with ansys and nTop.

Dear @Konstantinos Poulios

If I want to do compression test for my samples in experiment, I need to define two plate on the top and bottom of structure in nTop to mimic the boundary condition in reality, do you know about that how can I define this boundary condition in nTop? should I consider these two plate in nTop and then define tie constraints between them and my sample and export all of them to Ansys?

Dear @ Konstantinos Poulios

If I want to do compression test for my samples in experiment, I need to define two plate on the top and bottom of structure in nTop to mimic the boundary condition in reality, do you know about that how can I define this boundary condition in nTop? should I consider these two plate in nTop and then define tie constraints between them and my sample and export all of them to Ansys?

Dear Mansoureh Rezapourianghahfarokhi

As far as I remember from the student working on this, he defines the extra solid material in nTop but without defining any BCs. Then he imports the mesh to ANSYS WB and defines all BCs there. He has found the following method very useful for selecting the correct boundary nodes automatically:

https://www.padtinc.com/blog/beyond-clicking-named-selections-move-to-the-worksheet/

.

Mansoureh Rezapourianghahfarokhi Can you share a sample .stl file from nTopology software?

Dear Konstantinos Poulios thanks for your reply, yes actually it is possible to define solid plates at the top and bottom of our samples in nTop, but the connection between them is important. in nTop we can define just Tei and bonded connection between sold part and sample. Bonded connection is not suitable for comparing with compression test in reality, So we have just one option of tie constraint to choose.

Just I am in doubt about the tie constraint. it can mimic the real situation of compression test to not.

Does he have any published paper that I can read?

dear Dawit Alemayehu

Dear Nils Wagner Do you mean from my lattice? or any type of structure just an STL file?

From the lattice structure

Nils Wagner Sure I should prepare that in STL format. I will send you.

Ok, so your top/bottom plates are not printed together with the lattice. In our case we have top/bottom plates which are merged with the lattice. Then in your case, I would recommend you to model the plates in ANSYS and define frictional contact between your imported lattice and the plates in ANSYS. Just be careful to fix rigid body translations of the lattice parallel to the clamping plates because friction is normally not sufficient to give you a well defined model.

Konstantinos Poulios thank you for your guidance, actually, this is my goal, how to define contact between my sample and plates in nTop.

As you know I should import everything together from nTop to ansys. I should define the type of contact in nTop correctly.

I will test tie connection type, if I get a good result I will share it here. I hope everything goes well :)

You can write a small python macro in ANSYS importing the wire structure. Therefore, you have to loop through the wireframe elements, specify a certain cross-section and you finally get the result.