Joining of Very Large, Low Cost Pultruded Advanced Composite Structures in Shipbuilding

"Composite structures offer the shipbuilding industry the potential to reduce weight and eliminate corrosion, however cost of even "inexpensive" VARTM manufacturing of large composite sections has proven to be too high for designers to consider compositesfor anything other than special applications. KaZaK Composites and Bath Iron Works have teamed to begin development of a combination of very large scale pultrusion processing and special joints tailored to simplify the integration of these large pultrudedpanels into ship structures. We project that this new combination of technologies can reduce the cost of very large composite ship structures to less than half the cost of VARTM structure, and begin to approach the cost of steel construction. We propose atwo part Phase I effort. First, we will employ our 10-foot wide pultrusion machine to make 1-inch thick solid laminates and also composite sandwich panels. Specimens cut from these pultrusion will be tested to begin establishment of a mechanical propertydata base containing information derived from the large pultrusions typical of ship structures. Second, we will conceive of, analyze, fabricate and test a set of composite joints specialized for integration of large composite panels and steel shipsubstructure. KCI believes that the key to achieving the cost reductions necessary to initiate a widespread acceptance of composite materials in place of more conventional steel in application