Local buckling load of small cylindrical shells: an energy approach

Thin-walled stiffened or unstiffened, metallic or composite shells are widely used structural elements in aeronautical and space applications. These structures are often highly sensitive to initial imperfections and therefore have buckling loads much lower than those computed for perfect structures. Analysis and testing of imperfect shells have been a major research area during the last century. The proposed paper presents the results of the buckling analysis of small cylindrical shells, and their comparison with experimental results. For the analytical work, a hierarchical multi-fidelity approach is used to solve the buckling problem. As a first level analysis some simple programs are used to investigate the behaviour of perfect shells. The deformation in both axial and circumferential direction is described using goniometric functions. This is followed by more advanced analytical programs where the deformation in circumferential direction is still described using goniometric functions, but in axial direction the deformation is solved from the differential equations. Finally, the local buckling phenomena as observed during the experiment is looked at more carefully by investigating the energy behaviour.