Hi. You shouldn't use uniform area loads but surface pressure, which can be applied to any of the shell faces, previously dividing the linear distributed load by the wall thickness. Or you can use a ficticious frame element with low stiffness as you ve been told before.
Hi.
Another option to model the initial bow deformation it is by introducing a 'strain' load that causes bending in the beam(asign-- frame loads---strain---curvature3axis or curvature2axis....). It should be introduced in a nonlinear load case-1. Then your geometric nonlinear analysis with P...
