Multiple layers shell

Hello!! is it possible to create a shell that is made up of multiple layers? Example: a 2cm layer of concrete and a layer 4cm above in another material? how you do it? thanks so much

Hello - OffSetSrf, at the various distances, is I guess what you are looking for.


Yes, I can create two surfaces, but then?

Right - I guess I thought that is what you are asking for? If the objects are disjoint, then they will stay separate. What is the goal, exactly?


I’m sorry maybe I explained badly. I don’t know how to say. I wish that there were layers joined together, consequent but with different material and thickness! If I simply have two meshes and convert both to shells with the “mesh to shell” command and for each I decline the thickness and material, I can’t find the result! As if they overlapped, they were not considered united and above all I have problems in defining the support . I don’t know if I have explained myself better, I hope so

It’s my mistake!!! I did’t specify that I’m using Karamba. Sorry, I don’t know if you can how to use Karamba

Hi @fallarinomonica
You should probably edit the category of your first post and put it in “Grasshopper>Karamba3D” instead of the “Rhino for Windows” category. That way more of the Karamba users will see it.
HTH, Jakob

I agree with you! I have just corretted! Thanks u

Dear @fallarinomonica, currently it is not possible to define shells with multiple layers or materials. Unfortunately you currrently can only define one layer with one material per shell.

Is it not possible in any way to do what I asked for? If in “assemble model” command I insert the two layers with their respective material and thickness, won’t it calculate them as a unique structure?

It is possible in Karamb3D to define two shells which occupy the same space. It is however not yet possible to specify shell eccentricities.
You could try to connect two shells via stiff springs.
– Clemens

Ah. Could you be more specific? What does “You could try to connect two shells via stiff springs” mean? Is there a command?

Hello @Monica,
use short beams not springs (I made a mistake in my prior comment) which are oriented perpendicular to the plate, to rigidly connect the nodes of the top and bottom layer - similar to dowels. In this way the two plate layers act as one cross sections.
The problem is the exact choice of the stiffness of the beams. If they are too soft, one gets excessive shear deformation between the layers. If they are too stiff, the stiffness matrix of the system gets ill-conditioned which leads to inaccurate results.
– Clemens