7 .16 because hard points or stiffeners cannot be easily deposited to the hull surface for attachment purposes. The next proposal was a combination of a wire-wrapped structure with vapor deposition used to form a metallic matrix for the wires. An analogy to this technique would be a "metallic-fiber composite" hull. The manufacture of the wire could be done with comparative ease and wire forming machines can produce wire at very high output rates (several meters/sec). A wire-wrapped structure could be considered fail safe because the layers of wire wrapping supposedly make a redundant structure. This implies that the structure can withstand many individual wire failures without a major failure of the hull assembly. However, the authors discovered that a limited amount of knowledge dealing with this assembly technique exists in published literature. The assumed high yield stress obtainable from the thin filaments of metal cannot yet be justified for the finished fiber-metal matrix. The inherent fail safety of the individual fibers has not been experimentally shown at this time and leaves the question of accident damage uncertain. An efficient and inexpensive repair technique is also lacking for this assembly method. An interior pressure seal must still be provided with this wrapping technique as well as hard points for attachment of interior structures. Finally, it is unclear if the assembly procedure, consisting of several wire producing machines wrapping the wire around the base shape, is without unnecessary complications. Finally, stiffened plate/shell construction·was considered. Small plates would be welded together with stiffeners between the plates to serve three purposes: the stiffeners provide extra bending stiffness; they provide a convenient attachment point for interior structures; and they provide a means to sto~ cracks on one plate from propagating to an adjacent plate. State of the art inspection techniques exist for both plates and beams (see Section VIII.8.2) before and after assembly which help to guarantee structural reliability. The structure can be designed to be damage tolerant. The repair of a damaged section is straightforward and insures the maintenance of structural integrity after repair. Finally, the stiffened plate
RkJQdWJsaXNoZXIy MTU5NjU0Mg==