Development of High Strength Filament Wound Composite Pressure Vessel with Variable Thickness

Composite pressure vessels developed by filament winding technology falls into two categories i.e., pressure vessels with equal pole openings & unequal pole openings. Usually composite pressure vessels with equal pole openings can be developed with geodesic paths. Geodesic lines connect two points along the shortest distance over the surface. In this case no friction force is required to keep the fiber from slipping, since it follows a self-stable trajectory. There are, however situations where it is not possible to place fibers, at least in some region of the mandrel, on the geodesic curve. It implies that we have to resort to modified helical winding (non-geodesic) at cylindrical portion or dish ends or both. A composite pressure vessel like CRMC (composite rocket motor casing) with unequal pole opening is an example of this. In the present study, a composite pressure vessel with unequal pole openings considering deviation from the geodesic path only on the cylindrical portion is designed, developed and tested for burst pressure. The shell is subjected to uniform internal pressure and the conditions of thin walled structure and balanced symmetry winding pattern with carbon T300/Epoxy are considered.