A NOVEL JOINING METHOD FOR SMOOTH-BORE COMPOSITE PRESSURE HULLS

Filament wound smooth-bore composite pressure hulls offer the potentia l for increasing the displacement-to-weight ratios of externally loade d, hydrostatic pressure hulls well beyond those achievable with conven tional metal alloys. Increasing the displacement-to-weight ratio affor ds the ability to extend the operational pressure without a correspond ing weight penalty. However, for viable hydrostatic pressure hull desi gns, reliable attachment methods for interfacing the composite structu re with existing metallic components must be developed. While signific ant work has been done in composite-to-metal joining, developmental th rusts have not focused on problems specific to the design and fabricat ion of circular joints. The present paper discusses a novel circular c omposite-to-metal bonded joint developed for smooth-bore composite pre ssure hulls. Details of the concurrent engineering approach, fabricati on method, and validation testing of the cylindrical joint are present ed. Validation test results demonstrate that the novel circular joint is a viable alternative to more complex and costly composite-to-metal circular bonded joints.