Learning Forum

[shamik062]

Hello everyone

I want to generate a mesh (as attached in mesh.jpg file) on my model in symmetric manner. But unfortunately I can not get the desired shape of the mesh with the available shape control. Instead I am getting a mesh which is unsymmetrical as shown in the "Unsym_Mesh.jpg" file.

Is there any way by which I can generate a mesh like the one shown in mesh.jpg file?

A isometric image of the full model and the project file is also attached for reference

Thanks in advance.

[peteroznewman]

Why spend so much time to get a perfectly symmetric mesh?

I recommend you spend your time getting a result from the initial mesh you have, remesh with elements that are smaller by a factor of 0.65 and get that result, then remesh with elements smaller by a factor of 0.65 again (0.42 of the original element size) and get that result.  Plot those three results (like max stress) on a graph vs. element size and see if the results are converging on a zero element size value.  This is called a mesh refinement study and is much more valuable than making a perfectly symmetric mesh.

[shamik062]

Thank you for your reply and I totally agree with you. But my question was purely out of curiosity. I mean if I can manually do that symmetric meshing (in AutoCAD) why can't I do that in Ansys. Also you mentioned about the factor of 0.65. Is it arbitrary or is there any mathematics behind it? 

So, If I want to make my mesh like the one shown in symmetric one, how can I do that? Or is it at all possible by the controls available in Ansys.

Thanks again for your reply.

[peteroznewman]

The factor of 0.65 is not exact, its reciprocal is about 1.5 and a divisor between 1.2 and 2.0 is generally acceptable for the constant ratio of element sizes in a mesh refinement study.

Yes, it's possible to make a symmetric mesh if you slice the bodies up using planes into 4 quadrants and put the pieces in a multibody part to use Shared Topology, you can achieve symmetry.

[sk_cheah]

You could do mesh decomposition into quarters and specify hard line mesh sizing for each quarter of the circumference. Example here: Link

Kind regards,
Jason