Hoop winding

The primary classes of FW are hoop, polar, and helical. The simplest is hoop or circumferential winding, in which fibers are wound approximately normal to the mandrel axis of rotation with the fiber payout head advancing one band width for each revolution of the spindle. Hoop winding is usually combined with helical winding in more complex parts. Polar or tumble machines are used for parts wound using a planar winding path (such as for a short closed-end pressure vessel). These machines normally have the mandrel mounted vertically, over which a rotating arm wraps fiber onto the mandrel. 

The systems can include many options surfiice veil, chopped liners, sprayed resin systems, hoop winding strands, helical winding strands, resin bath, unidirectional tape, woven roving tape, pigmented resin surfaces, wax-resin surfaces, gel coats, BPO catalyst, epoxy resins, vinyl ester resins, filled resin systems, abrasive resin systems, polyester foam, syntactic foam, and charting film. 

The addition of pure hoop windings to the helix gives a theoretical gain in stability with no loss of strength or efficiency. In order to develop the ... 

Figure 21.58 Circumferential or hoop winding. Source Reprinted with permission from Shaw-Stewart D, Filament winding-materials and engineering, Materials and Design 6, No. 3, 1985. Copyright 1985, Elsevier.

The same test method, although not standardized, can be used to characterize the laminate in-plane shear behavior. This is accomplished by winding a multiorientation (hoop/helical and/or helical only) tube. Other test methods that can be used to measure in-plane shear stiffhess/strength of filament wound composites are discussed by Tamopol skii and Kinds [45]. These methods include schemes for torsion of intact rings and split rings. Both of these ring test methods are used to evaluate the in-plane shear modulii G0r and G0z for a filament-wound laminate. 

Attention focuses on the cylindrical section of the hydrogen vessel subjected to internal pressure with close-end effect loading (Figure 1). The itmer radius Rq and its thickness e are constant. The vessel strength is ensured by Ug layers of filament wound composite. The k layer is characterised by its thickness ep(k) and winding angle P(k). The radial, the hoop and the axial coordinates are respectively denoted by r, 0 and z. Regarding at the usual assumption, the displacement fields is expressed as ... 

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