Prediction of vacuum-induced buckling pressures of thin-walled cylinders

The effect of geometric imperfections on the buckling capacity of thin cylindrical shells subjected to uniform external pressure is investigated in this paper. Geometric surveys were conducted on small-scale thin cylinders in order to measure geometric imperfections of the shell surface. These imperfections were then modelled in the FE analysis and a geometrically nonlinear static analysis was carried out. The cylinders are tested to collapse in the laboratory and the results are compared to the results of the FE analysis. Both collapse pressure and postbuckling mode shape are accurately predicted by the FE analysis.