Simple Calculations for the Stability of Soft, Thin-Walled Mandrels During Filament Winding

During filament winding of a laminated pressure vessel over a flexible, thin-walled mandrel, the winding tension produces an external pressure on the mandrel which tends to buckle it. A simple analysis which adequately describes the physical behavior of the vessel is given in a very convenient form. Using the analysis method, various internal pressurization schemes are discussed which not only prevent buckling, but also permit control over dimensional changes and relaxation or overtension in the fibers. The theory is illustrated by an example.