Filament-winding dome

Filament-wound structures are typically cylindrical, spherical, or conical. In the case of cylindrical or conical shapes, there may be domed ends or specially wound flange ends. The fibers and resins can be selected from a wide variety of materials. These material and geometry options make filament winding a versatile manufacturing process. 

It is possible to wind domes with a single polar port integrally with a cylinder comparatively easily without the necessity of cutting filaments. Cutting is obviously not desirable, since it interrupts the continuity of the basically orthotropic material. The usual procedure in winding multiported domes is to add interlaminate reinforcements during the winding operation where the ports are to be located. 

Slip angle pattern Angle at which a tensioned fiber will slide off the filament wound dome. If the difference between the wind angle and the geodesic angle is less than the slip angle, the fiber will not slide off the dome. Slip angles for different fiber-plastic systems vary and must be determined experimentally. 

In the filament winding process a mandrel is rotated upon which are wound reinforcing fibres which have been impregnated with resin. The fibre is controlled by an applicator which traverses the length of the mandrel as it rotates, thus building up the laminate thickness. A surface of revolution is produced, the type (cylinder, cone, etc.) depending on the mandrel shape. Variations include extra axes of movement to allow the winding of domed ends, spheres, conical shapes, etc. 

As can be seen in Fig. 4, the composite thickness varies along the vessel being maximum near the gas valve (dome) due to the filament winding stacking process. The increase of thickness due to the central weld line was also taken in consideration. 

The mechanical properties of the filament wound composite are a complex combination of (a) winding pattern and thickness and (b) resin and filament properties. The mechanical properties of the dome regions, in particular, require specialized treatment. The interested reader is referred to the text by Fubin for more information. 

Planar helix winding n. A winding in which the filament path on each dome lies on a plane that intersects the dome, while a helical path over the cylindrical section is connected to the dome paths. 

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