Ansys Workbench: Linear Buckling (Eigenvalue Buckling)

An hollow cylinder of length 1000 mm, diameter 100 mm and shell thickness 1 mm is submitted to kinematic boundary conditions of ux=uy=uz=0 on its extremity at z=0 and ux=uy=0 on the one at z=1000. A global compressive load-state is obtained with the application of a unit force in direction -z on the cylinder's extremity at z=1000. The constitutive material is considered linear, elastic and isotropic with a Young modulus of 210 GPa and a Poisson ratio of 0.3.
Such a slender solid submitted to compressive stress (not necessarily global by the way) may exhibit a bifurcation in its response to increasing load intensity. After reaching a critical value of the load intensity, the solid may indeed respond on a 'mode' different from the one observed for sub-critical loads. This phenomenon is called buckling. The purpose of this video is then to provide a demonstration of the 'eigenvalue buckling' module in Ansys Workbench [1] for the modelization of linear buckling problems.
Questions :
1- Perform a convergence analysis on the influence of the mesh size (for 4 nodes quadrangular and 6 nodes triangular shell elements) over buckling results (load multipliers and modes).
2- Study the influence of the Young Modulus on buckling results.
3- Study the influence of the Poisson ratio on buckling results.
4- Study the influence of the the shell thickness on buckling results.
5- Study the influence of the the slenderness ratio height/diameter on buckling results (the diameter is to be kept at its initial value).
6- For design purposes, propose a synthetic graph (horizontal axis : slenderness ratio from 1 to 10, vertical axis : load multiplier) that allows to evaluate the first buckling critical load for thicknesses ranging from 0.5 to 5.
[1] An academic version of Ansys can be downloaded for teaching and learning purposes there: www.ansys.com/...