Merge branch 'main' of https://gitlab.ethz.ch/florez/florez_akantu into main

shell_cyl.geo

-//+
-SetFactory("OpenCASCADE");
-//+
-t = 0.05;
-Circle(1) = {0, -0, 0, 0.5, 0, 2*Pi};
-Circle(2) = {0, -0, 0, 0.5+t, 0, 2*Pi};
-//+
-Extrude {0, 0, 5} {
-  Curve{1}; 
-}
-
-Extrude {0, 0, 5} {
-  Curve{2}; 
-}
-//+
-Physical Surface("Inside") = {1};
-//+
-
-Physical Curve("top") = {1};
-//+
-Physical Point("fixpoint") = {3,4};
-//+
-
-//+
-Curve Loop(3) = {6};
-//+
-Curve Loop(4) = {4};
-//+
-Plane Surface(3) = {3, 4};
-Physical Surface("bottom") = {3};
-//+
-Curve Loop(5) = {2};
-//+
-Curve Loop(6) = {1};
-Plane Surface(4) = {5, 6};
-//+
-Surface Loop(1) = {3, 2, 4, 1};
-//+
-Volume(1) = {1};