EFFECT OF GEOMETRIC IMPERFECTIONS ON NONLINEAR STABILITY OF CYLINDRICAL SHELLS CONVEYING FLUID
Circular cylindrical shells conveying subsonic flow are addressed in this study; they lose stability by divergence when the flow speed reaches a critical value. The divergence is strongly subcritical, becoming supercritical for larger amplitudes. Therefore the shell, if perturbed from the initial configuration, undergoes severe deformations causing failure much before the critical velocity predicted by the linear threshold. Both Donnell’s nonlinear theory retaining in-plane displacements and the nonlinear Sanders-Koiter theory are used for the shell. The fluid is modelled by potential flow theory. Geometric imperfections are introduced and fully studied. Non-classical boundary conditions are used to exactly simulate the conditions of the experiments performed. Comparison of numerical and experimental results is performed.