Buckling analysis of cylindrical shells with cutouts including random boundary and geometric imperfections

In this paper, the effect of random geometric imperfections on the critical load of isotropic, thin-walled, cylindrical shells under axial compression with rectangular cutouts is presented. Second moment characteristics of geometric imperfections are estimated by data of available measurements, a simulation procedure based on the Karhunen–Loève expansion is applied for generating realizations of geometric imperfections. Nonlinear static finite-element analyses are carried out for the calculation of the response statistics of the critical load of the cylindrical shells. Cumulative distribution functions of the critical load as obtained by direct Monte Carlo simulation are presented. Furthermore, the individual and combined effects of random boundary and geometric imperfections on the limit loads of isotropic, thin-walled, cylindrical shells under axial compression are also treated. Again, second moment characteristics of these imperfections are estimated by data of available measurements of imperfections, a simulation procedure also based on the Karhunen–Loève expansion is applied for generating realizations of both boundary and geometric imperfections. A nonlinear static finite-element analysis using the general purpose code STAGS [C.C. Rankin, F.A. Brogan, W.A. Loden, H.D. Cabiness. STAGS (STructural Analysis of General Shells) User Manual, LMSC P032594, Version 3.0. Lockheed Martin Missiles and Space Co., Inc., Palo Alto, CA, USA, 1998] is carried out for the calculation of the buckling response of the cylindrical shells. Finally, the cumulative distribution functions of the limit load using direct Monte Carlo simulation are shown.