SENSITIVITY ANALYSIS OF AXIALLY COMPRESSED CYLINDRICAL SHELLS WITH PROBABILISTIC AND DETERMINISTIC METHODS

Abstract

Thin-walled unstiffened cylindrical composite shells are prone to buckling. The structural behavior of these shells responds really sensitive to initial geometric imperfections, which occur during the manufacturing process of an unstiffened composite cylinder. Geometric imperfections like small dimples cause a deviation from the perfect geometrical shape of a cylinder and can reduce the buckling load significantly. Scattering of material and geometric parameters as well as an inhomo-geneous loading causes also a reduction of the load carrying capability of these cylinders. Re-search’s mainly investigated the influence of geometric imperfections on the buckling load and ignored the other sources of imperfections. In this paper the before mentioned imperfections and their effects on the buckling load of cylindrical shells are investigated using a semi-analytical prob-abilistic sensitivity analysis. With this method the structural response behavior of the cylindrical shells is evaluated in order to identify imperfections which are most critical in terms of stability behavior. The study is performed for shells with equal material und geometric parameters but different laminate stacking and the imperfections are classified into different degrees of priority using indices. The purpose of this paper is to identify imperfections which are most critical on the stability behavior of unstiffened cylindrical composite shells to show where to spend resources for the largest improvement of future guidelines for imperfection sensitive composite launcher structures.