Filament-winding netting analysis

The filament-wound sphere design structure provides another example of a balanced netting analysis system (Chapter 5). It is simpler in some respects than the closed-end cylinder. The sphere must be constructed by winding large circles omni-directionally and by uniform distribution over the surface of the sphere. In practice, distribution is limited so that a small polar zone is left open to accommodate a connecting fitting. 

Prototype composite vessels (Fig. 12) were manufactured in the conditions used in the FEM simulations using a 6-axes CNC controlled filament winding machine and submitted to hydraulic burst pressure tests. The obtained results have shown that vessel burst occurred for pressures between 8 and 11 MPa. Such results show that conservative results were obtained from FEM analysis probably because failure does not occur by interlaminar shear as other simplified theories, like the netting one, demonstrate. 

---