Excellent lecture hocam! As a former student of yours, this brings back a lot of good memories. I humbly offer my comments for you and future engineers to consider. It might be worth exploring/comparing a displacement boundary condition at the bottom surface using cylindrical coordinates where only the radial direction is allowed to expand taking Poisson’s ratio effect into account as fixed BC can sometimes over constrain the model. In this case it doesn’t matter because it’s a shell but for 3D it should. Utilizing symmetry can also save computational cost, half, quarter or even 1/32 for simple circular shapes. It’s very useful to know how does ASME Boiler and Pressure vessel code deal with interpreting stresses for linear and non linear analyses such as stress linearization and limit stress methods. Best regards, Omar Youssef