Buckling of Imperfect Elastic Shells using the Asymptotic Numerical Method

International audienceThis paper is concerned with stability behaviour and imperfection sensitivity of elastic shells. The aim is to determine the reduction of the critical buckling load as a function of the imperfection amplitude. For this purpose, the direct calculation of the so-called fold line connecting all the limit points of the equilibrium branches of the imperfect structures is performed. An augmented system demanding the criticality of the equilibrium is used. In order to solve the augmented system, the Asymptotic Numerical Method is used as an alternative to Newton-like incremental-iterative procedures. It results in a very robust and efficient path-following algorithm that takes the singularity of the tangent stiffness matrix into account. Two specific types of imperfections are detailed and several numerical examples are discussed