Mesh loads: point load generation and meshing issues

Hi all!

I am working on a structure composed entirely by shells; therefore I mostly use the mesh load component to generate equivalent point loads, and I have some questions about it.

In the model, I am applying the same load on all floor. However, I obtain different deformations, even though their geometry and loading are identical (they are mirrored by the central line, see picture). I assume that this is a meshing issue, given the output, as well as the meshes themselves: the more deformed they are, the more fine the mesh is (see other picture). I am using the Mesh Brep component from GH.

The question(s) (are) therefore:

1) How can I control this meshing? I am really surprised that I get different meshing for the exact same breps, that are simply mirrored. (This might be more a Grasshopper specific question but maybe you know the answer)

2) I chose the Mesh Brep component instead of the Mesh Surface component to create the shells. Indeed, when I used the second one, the elements could not detect the supports and I had huge deformations (Like 10e+11m...). Any idea why?

Thank you in advance for your help!

Simon

Attachments:

Troubleshooting_Modelview.PNG, 202 KB
Troubleshooting_Meshing.PNG, 70 KB

Replies to This Discussion

Permalink Reply by Karamba3D on May 10, 2017 at 1:10pm

Hi Simon,

the structural response of shells is dependent on the mesh refinement.

ad 1.) It is hard to say why the GH mesher gives different results for identically shaped surfaces - maybe the order of the boundary lines is different.

ad 2.) In order that a support is connected to a shell, the node where the support is attached needs to be a vertex of the shell mesh. The 'Mesh Breps'-component from the 'Karamba/Utilities'-section lets you include arbitrary points in a mesh via the input-plug 'IPts'.

Best,

Clemens

Permalink Reply by Simon Clavelin on May 15, 2017 at 4:47am

Hi Clemens,

Thank you very much for bringing the "Mesh Breps" component to my attention! It worked like a charm!

In case some people are encountering the first issue as well: I just plugged the custom settings components (with defaults values) into the Grasshopper "Mesh Brep" to force a minimum meshing. But in any case the Karamba "Mesh Breps" is better to ensure the connectivity of the elements.

Simon

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