Applying Gravity Load to Shell - New Karamba User


I am new to Karamba and FEM in general, so I am in the process of getting my bearings.

My goal is study how the included geometry sags as a function of decreasing modulus, thus my only load condition is gravity, with fixed supports at the tabs.

When I attempt to simulate this using Karamba, I am noticing this unexpected sagging towards the centroid of the part:

I brought the model into SimScale and ran the simulation with similar conditions and yielded this result, which is what I would expect:

Does anyone know where I am going wrong in my Karamba setup? Thank you for your help. (27.9 KB)

Hi @jptroise,
You need to analyze the geometry as a surface with a defined cross section rather than a solid. Please also take care of the units of the model. The deformation shows similar results to the image from SimScale. (53.6 KB)


Thanks @matttam

I appreciate your response. If I understand correctly, Karamba cannot operate on an arbitrary 3D geometry - I must decompose this 3D geometry into elements that Karamba can comprehend.

What is my recourse if the input geometry is not as simple as what I have shared - perhaps with variable cross section? I see that there is the Shell Var option. Shall this be my only alternative?


Yes, that is correct. You can use the shell variation cross section to define the thickness of all the mesh faces.