Karamba Analyze issue

Hi everyone,
I’m a structural engineer and I am just starting to play around with Grasshopper and Karamba.

I am facing an issue with the Analyze component. I’m getting the following error message:

“1. There are 18 rigid body modes in the system. This means some parts can move freely without causing deformation.
Try to use the ‘Eigen Modes’-component and activate the display of local coordinate axes: The first eigen-mode will be the rigid body motion.
If this does not help, check whether you have a pinned support directly attached to a hinge. A hinge introduces an extra node which may cause the problem.
When analyzing a flat shell structure one has to lock the rotation perpendicular to the plate in at least one node.”

I have looked for a solution online but although finding many threads about this topic, none of the solutions have worked. I would really appreciate it if someone could have a look at the attached file and give me a hand.

Many thanks,

KAD frame GH.gh (21.0 KB)

do you have any hinges applied to the ends of beams? what are support conditions?

Hi, your beams are not split at their intersections. Karamba3D does not recognise that there is a connection at that point (similar to all FE softwares) and therefore your structure is kinematic.

You can use the ConnectedParts component to check if there are parts of your model which is not connected:

KAD frame GH_mt.gh (35.5 KB)


Thank you very much for fixing this Matthew!

However, I can’t really see what is that you did. Where or how did you put connections between elements to stop it from being kinematic?


You need to make sure your beams are split at their intersections.