Buckling and Postbuckling of Truncated Conical Shells with Varying Semi-Vertex Angle: the Use of the Single Perturbation Load Approach

摘要

The importance of taking into account geometric imperfections for cylindrical andrnconical thin-walled structures in buckling had been already recognized a long time ago.rnNowadays, the designers still use empirically based lower-bound methods such as thernNASA SP-8007 guideline to calculate the required knock-down factors (KDFs). Newrndesign approaches that allow taking full advantage of using composite materials arernrequired.rnThe single perturbation load approach (SPLA), a new deterministic approach developedrnby Hühne for cylindrical shells, will be investigated with unstiffened composite conicalrnstructures. The SPLA’s capability for predicting KDF is compared with the NASArnapproach. The SPLA was applied to perfect conical shells with different semi-vertexrnangles, and three different positions of the perturbation load were considered. The studyrncontributes to the European Union (EU) project DESICOS, whose aim is to develop lessrnconservative design guidelines for imperfection sensitive thin-walled compositernstructures.