Filament winding polar

Figure 21.60 Polar winding. Source Reprinted with permission from Shaw-Stewart D, Filament winding-materials and engineering. Materials and Design 6, No. 3, 1985. Copyright 1985, Elsevier.

Polar winding n. In filament winding, a winding in which the filament path passes tangent to the polar opening at one end of a chamber and tangent to the opposite side of the polar opening at the other end. 

Reverse helical winding n. In filament winding, a pattern in which a continuous helix is laid down, reversing direction at each of the polar ends. It differs from biaxial compact, or sequential winding in that the fibers cross each other at definite equators, the number depending on the hehcal lead, with the minimum number of crossovers being three. 

Whirling-arm filament winding is illustrated in Figures 23 and 24. Polar wind is accomplished hy means of the C-shaped arm, which supplies filaments from feed eyes at both extremities. While whirling on its horizontal axis, the arm winds on the polar axis of the mandrel, which is circumferentially indexed at appropriate intervals. During polar wind, the horizontal winding arm is retracted ... 

Figpre 16.15 Schematic representations of helical, drcumferential, and polar filament winding techniques. 

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. 

Angle Winding angle is the angular measured in degrees between the direction parallel to the filaments and an established reference. It is usually the centerline through the polar bosses, that is, the axis of rotation. 

There is the ovaloid netting system that is the natural result of the reversal of helical windings over the end of the vessel. The windings become thicker as they converge near the polar fittings. In order to resist internal pressure by constant filament tension only, the radius of curvature must increase in this region. It can also be equal to one half the cylinder radius when the helix angle a = 0°, and equal to the cylinder radius when a = 45°. The profile will also be affected by the presence of an external axial force. 

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. 

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