High-fidelity design methods to determine knockdown factors for the buckling load of axially loaded composite cylindrical shells

Kurzfassung

The design of thin-walled structures still relies on empirical guidelines like the NASA SP-8007 for cylinders up till now. This lower-bound guideline does not include important mechanical properties of laminated composite materials, such as the stacking sequence. New design approaches that allow taking full advantage of composite materials are therefore required. Within this paper newly developed innovative design approaches for axially loaded cylindrical shells are pre-sented and validated by means of high-fidelity buckling experiments of unstiffened composite cylinders. The considered composite shells were designed, manufactured and tested at the German Aerospace Center (DLR) in Braunschweig. The results show that the buckling load can be determined very accurately in contrast to the previous methodology.