Results karamba 3D and matrixframe are different

I’m making a comparison between karamba 3d and matrix frame. With a beam on two supports (fixed and roller), the results do not correspond to the same load. Can this difference be explained?


I’m pretty sure the first graph is showing cut/shear stress and the second is showing bending stress.

Yes I know. The top two pictures are shear stress (Vz-line). The bottom two are bending moment (My-line). if you look at the maximum values ​​of the Vz-line and the My-line you see that these differ. left is matrix frame, right is karamba. The differences are huge.

The differences also occur with a beam on 3 supports (pinned, roller, roller)

The graph on rhino seems a polyline instead of a smooth curve.
It seems like the distributed load is converted in very few load points.

Can’t you increase the accuracy? If there is some…
(I don’t have the plugin.)

It’s not a smooth curve because the length/segment.

ligger-3 steunpunten verdiepingsligger (64.0 KB)

Then I have no idea. Maybe @matttam can help you.

Dear @1631349hunen,
the difference is due to the presence of shear deformations in the Karamba3D solution. If one reduces those by setting the cross section’s shear area in local Z-direction to a large value the bending moments coincide:
ligger-3 steunpunten verdiepingsligger (74.3 KB)
– Clemens


Ok thank you that’s clear, but I’m working with the free/trial version. I don’t have the "modify cross section"component. Is it also possible with another component?


Hello @1631349hunen,
you can use a C# script for that:
ligger-3 steunpunten verdiepingsligger (81.3 KB)
It could be that you have to update the path to ‘karamba.gha’ and ‘karambaCommon.dll’ in the C#-component (right-click on the component, ‘Manage Assemblies…’).
– Clemens