EPS Foam Structure


I am looking at a temporary EPS Foam Structure.
I’ve created my own material properties according to Foam.
I would like to test an interlocking mechanism that would assist with Foam’s ability to withstand lateral movement.
But first I need to understand how much I can span/cantilever with Foam.
According to my calculations (please find attached), I can span 1.35 m with a live load of 150 kg/m2.
Unfortunately, the Karamba structural analysis indicates that the material buckles on distances lower than 1.35 m.
Please find attached my GH script, Rhino file, and a sketch.
Apologies for the long post and thank you in advance!

Yoav190217_EPS Foam Structure Analysis.gh (68.1 KB)
190217_EPS Foam Structure_Rhino 5.3dm (103.8 KB)

Sorry your calcs look wrong. Better read a bit more on bending stress.

Also, I think it is better if the connections between the column and the beam are between mesh vertices.

Hello Yoav,
there are three problems in your definition (see attached files 190217_EPS Foam Structure Analysis_cp.gh (58.5 KB) and 190217_EPS Foam Structure_Rhino 5.3dm (103.8 KB)).
In order to solve these do the following:
1.) Flatten the output of the Materials-component, otherwise one gets multiple, partial models.
2.) Make the endpoints of the connectors vertices of the shell mesh in order to properly connect them. You can use the ‘IPts’-input of the ‘Mesh Breps’-component for that.
3.) Add rotational support conditions about the global X-axis to keep the structure from rotating out of the XZ-plane.


Hello all,

Thank you very much for your help, I really appreciate it.

Tim - I have been reading and embarrassed to admit that I’m very weak in that.
Can I ask for an example of how you would calculate with the given units?

Celemns - it works so much better, thank you!
May I ask why does the left interlocking connection has higher utilisation values?
Also, the top connection depicts reverse conditions (please find a screenshot attached).
Lastly, is it possible to hide the mesh grid to see the analysis results better?
When I hide the shell view the analysis disappears with

the mesh grid.


Hello Yoav,
you can find the material properties of EPS on the net.
The stress peeks could be due to the non-uniform mesh at the border between the two parts.
You can hide the mesh edges via ‘Display/Preview Mesh Edges’ in the Grasshopper menu.

Thank you!