Hexahedral meshing help needed

[aorsi]

Hello All,

So I am using ABAQUS. I have some irregular geometry structures, with hyperelastic material properties fitted to a marlow model, using ABAQUS' material evaluation package. I am trying to mesh these irregular geometries with a hexahedral mesh. This is because when I use a tet mesh, the model will not converge. I believe this is because my material deforms greatly, so the hexahedral hourglass controls are needed. I have tested the hex mesh with a uniform geometry structure, of similar proportions, using the hexahedral mesh with advanced hourglass controls and the analysis ran exceptionally well. I believe the key to my model is to incorporate this advanced hourglass control. But I am unable to mesh my irregular structures with a hex mesh. The tet mesh look great for my irregular geometries, however, there is no hourglass control parameter when using a tet mesh. I am wondering if there is a way i can account for the hourglass effect with a tet mesh, OR if there is a way I can get a hex mesh to work for my irregular structures. Any help would be GREATLY appreciated. I have both SAT files and IGES files for both structures, if anyone has any ideas, please let me know.

Thanks a bunch,

-Alex

 

[corus]

Only two of the parts will hex mesh. The remaining two are too complex to break down into meshable regions and even if they were, the parts have a very sharp corner that may give poor results for a hex element.
Using quad tet elements, you may just have to change the mesh density to try and get the models to work.

Tata but not yet tara

 

[aorsi]

Hello Corus,

Thank you very much for the response. I am wondering if you could let me know which files you are talking about when you say "2 of the parts will hex mesh". I only have 2 parts. But my attachment provides both .IGES and .SAT for both parts. I am excited about the fact that you have been able to hex mesh these. If you could provide more insight into how this was done, I would greatly appreciate it. to recap.

1 - Please clarify which parts you were able to hex mesh
2 - How were you able to hex mesh these parts...using abaqus?

Thanks again,

Sincerely,

-Alex

 

[corus]

I opened up two of the sat files and imported them as parts. I think they were called 1.sat and 2.sat. The four parts from the files looked to form two human teeth, similar in shape, but I think slightly different. Taking one of the teeth, they semed to form a more regular squarish shape, topped with a sharp tooth. The more regular shaped hex meshed without needing and preparation just using the default mesh size. The sharp tooth, I could see no way of partitioning it to enable hex meshing using Abaqus.

Tata but not yet tara

 

[utkk]

Hello aorsi
If you want hexahedral mesh in your model I thing you must use other program for meshing such as Altair hypermesh and you can import your model to abaqus program after meshing fineshed. orther way using quad tet element in abaqus that its effect of quad tet is reduced element stiffness.
Thank you and good luck

Rubber engineering