Thank you for the advice!
I’ll try to find some information on that book.
I thought of beam elements, but for me, they are not an option at the moment as they do not funtion together with composite option on shell card ( Add Point Mass for natural frequency model? (v1.3.0) - Feature Requests - PrePoMax)
For the mesh I prepared a paramatric sketch in cad where I can change the legth of the squares edge and the hole diameter. I copy/paste that on each hole an “print” breps on the surface.
Then I can define a coarse mesh with only one element per edge /curvature and the holes will still be meshed properly. I find that to be quicker in the end compared to fiddeling with the settings of the mesh or doing it in gmesh.