BUCKLING OF CYLINDRICAL-SHELLS UNDER EXTERNAL-PRESSURE PROPOSITION OFA NEW SHAPE OF SELF-STIFFENED SHELL

We propose a new shape of cylindrical shell formed by multiples vaults which gives a self-stiffening against buckling. By an experimental an d numerical study of cylindrical shells with a repeated defect, on the circumferential direction made only of outside oriented wave-defects, we show that multiple vault cylindrical shells can have a good behavi our in buckling. An optimal behaviour is obtained by optimization of t he vaults number, with conduces to a special multiple vault cylindrica l shell named ''ASTER shell''.