Hi there,

I am trying to figure out how Karamba3D works compared to other FEM software I have used.

I am a little puzzled after trying to conduct a mesh refinement analysis on a simple beam. And would appreciate a pointer to what is different in Karamba or where I am off in my line of thought.

I modelled a simply supported beam and increased the number of elements from 2 to a hundred, measuring the displacement at midspan:

In the plot I also visualized the analytically computed value. I am surprised that upon increasing the number of elements (line to beam) there is no conversion of my numeric solution, but already with 2 elements my solution has converged. The solution is pretty good considering that the deviation is < 2%, but the behavior after conducting this analysis I do not understand. I would expect that with increasing number of elements my solution would converge to the analytical solution.

Another point, though somewhat related, I am used to from other FEM software that geometry development and meshing are to separate processes. In Karamba they are more closely related, correct? Because with the geometry that I input into e.g. the line to beam component I define my “mesh” or beam elements.

I am also a little confused by the effect of the Length/segment slider under render settings in the model view. This does not have an influence on the results of the analysis,

simplebeam_meshrefinement.gh (64.4 KB)

correct?

Some questions, which are all somewhat related in my mind. Any response is appreciated!

Best,

Chris