Imperfect, laminated, cylindrical shells in torsion and axial compression

Abstract

An imperfect, laminated, circular, cylindrical thin shell, simply supported at the boundaries, and subjected to a uniform axial compression and torsion (individually applied and in combination) is analyzed. The analysis is based on nonlinear, Donnell-type, kinematic relations, linearly elastic material behavior, and usual lamination theory. The laminate consists of orthotropic laminae, which typically characterize fiber reinforced composites. Numerical results (critical loads) are generated for several geometries and some of these results are compared to available experimental data. The imperfection sensitivity of the various geometries is studied. It is clearly shown that the laminated shell is more imperfection sensitive under pure axial compression than under pure torsion (same as for the isotropic geometry). The effect of the orientation of the laminae (stacking sequence) on the critical load is also studied.