I am actually working on a 3d truss, I need to make a structural analysis using the GSA workbench.
I can make analysis with an automatic mesh (generated by catia). But I have several load cases so in order to decrease the time of processing I would like to lighten the mesh.
Here is a picture of what I would like to do :
The mesh is rectangular between the two junctions but when it gets closer to the junction, it becomes triangular and smaller.
How is it possible to do that?
I have tried by making a little groove where I wanted to change the type of mesh but it leads to a mesh problem.

In summary, how do we make a progressive (bigger to smaller elements) and shape changing (rectangular to triangular) mesh on a tube?

Thank you in advance