Non-linear buckling analysis - complex loading

Hi all,

I have attached a single slide ppt file with this blog. In this slide, there is a hollow cylinder subjected to internal pressure and non-uniform axial load. All the translations at the bottom of the cylinder are fixed. As a whole the cylinder is subjected to a complex loading. The cylinder is modeled using SHELL elements in ANSYS. Now I know how to carry out non-linear buckling analysis in ANSYS.

There is one more sketch in the slide. A column is subjected to a compressive load and also an infinitesimal lateral load to give perturbation. After carrying out non-linear buckling analysis on this column, we plot axial load vs lateral deflection. Here we get a non-linear load-deflection curve. This is clear.

I have the following fundamental questions in case of a cylinder, which is subjected to a complex loading as discussed above.

(a) To plot load-deflection curve what nodal points shall I take for load and deflection?

(b) Load direction is axial and deflection is radial - correct???

(c) Insted of point loads (F1 and F2), if I have axial pressure applied over the thickness, in elemental solution (/post26) I can get the force. How can I convert this to pressure to get the critical buckling pressure?

I request some body to calrify the above doubts.

With regards,

- Ramadas