Dear (and patient) experts,
I’m trying to model a thin walled cylinder with variable cross-section, but I’m observing three weird things in the buckling modes. Here you have the GH file: SellTower3.gh (105.6 KB)
The lowest buckling factor (BF) increases as the mesh size decreases (please use the “Mesh size” slider to change it and check the BF value near Galapagos component). I think that it should happen exactly the opposite since the structure becomes less stiff when element size is reduced. Am I doing something wrong?
Three different triangular meshing patterns were coded and tested (Mesh-UV, Alternate, and UV-Like) that can be selected using the drop-down box in the Model Selector group. If you switch between them, you will see that the ripples of the first buckling mode are a bit twisted when Mesh-UV and UV-Like meshing patterns are selected. Only the Alternate meshing produces the expected horizontal ripples. Would this be related to using triangular shell elements? If so, is in Karamba to-do list the implementation of quad shell elements?
As expected, the maximum displacements and utilisation are the same in all of them. However, the buckling factors are slightly different (around 5%) between Alternate and “UV” meshes. The later (Mesh-UV and UV-Like) are essentially the same.
Thank you very much and congrats for the excellent software!
PD: Is there any way to easily visualise the shell elements (edges and thickness)? I had to plot the lines of the triangles manually and the thickness visualisation of individual elements is not very accurate.