mesh model for GSA?

Replies to This Discussion

Permalink Reply by Corrado Giacobazzi on February 20, 2011 at 3:39pm

Check this discussion!

Cheers

Permalink Reply by Yi Lü 吕谊 on February 20, 2011 at 4:09pm

thank you very much! it solves my problem.

Permalink Reply by Yi Lü 吕谊 on February 20, 2011 at 4:26pm

what means "Warning in Elements: angle around node is small."

 

what can i do for it?

Permalink Reply by Jon Mirtschin on February 20, 2011 at 10:17pm

The Rhino mesher is tuned primarily for visualization.  To get most accurate FEA from less faces in your model, each face should be squarish (aspect ratio) and without acute angles (ie for a triangle one very short edge and two very long or similar for quad).  

 

How are you producing the mesh?  There are means and ways to inform the rhino mesh settings to try and produce better mesh.  I also have a grasshopper component/rhino command to "resize" mesh to try and produce more analysis friendly mesh, but check the result of it carefully as there were some scenarios where it was leaving holes.  

 

Another option I am looking at is enabling an external mesher into rhino/grasshopper that produces analysis mesh, but I am still in early phases of trying this.

Permalink Reply by Yi Lü 吕谊 on February 21, 2011 at 8:26am

that's nice! when will you release it?

Permalink Reply by Yi Lü 吕谊 on February 21, 2011 at 8:27am

any good idea to get a good mesh model of this for GSA?

Attachments:

• sphere.jpg, 287 KB

Permalink Reply by Yi Lü 吕谊 on February 21, 2011 at 11:07am

im now using gmsh from http://geuz.org/gmsh/. for now it's ok, better than meshing in rhino.

Permalink Reply by Jon Mirtschin on February 21, 2011 at 12:42pm

Yes, that is the mesher I was looking to enable in Rhino/Grasshopper (without manually exporting to IGES or equivalent).

 

Spheres are difficult in nurbs, because of the poles.  If you can arrange your booleans to clip them, you can get acceptable results (refer attached).

 

Cheers,

 

Jon

Attachments:

• 110221 mesh sphere.ghx, 172 KB

Permalink Reply by Yi Lü 吕谊 on February 21, 2011 at 12:57pm

Hi Jon,

thanks a lot. i don't know why i can not load the results of GSA back to Rhino. i did it for the Maximum 2D Moment.

Permalink Reply by Jon Mirtschin on February 21, 2011 at 1:54pm

I'll have to enable maximum 2d moment (or try to make it more generic).  As soon as I finish generation of loads that I have been working on, loading results (including within grasshopper) will be one of the next priorities.