Test Results for Composite Specimens and Elements Containing Joints and Cutouts.

Under Contract NAS1-17701, McDonnell Douglas conducted a program to develop the technology for joints and cutouts in a composite fuselage that meets all design requirements of a large transport aircraft for the 1990s. The development plan encompassed a multifaceted engineering, manufacturing, and testing effort to develop the technology for fuselage joints and cutouts. This report covers the test efforts associated with that program. An advanced trijet derivative of the DC-10 was selected as the baseline aircraft. Design and analysis of a 30-foot-long composite fuselage barrel provided a realistic basis for the test effort. The primary composite material was Hexcel F584 resin on 12K 1M6 fiber, in tape and broadgoods form. Fiberglass broadgoods were used in E-glass and S-glass fiber form in the cutout region of some panels. Additionally, injection-molded chopped graphite fiberPEEK was used for longeron-to-frame shear clips. The test effort included four groups of test specimens, beginning with coupon specimens of monolayer and cross-plied laminates, progressing through increasingly larger and more complex specimens, and ending with two 4- by 5-foot curved fuselage side panels. One of the side panels incorporated a transverse skin splice, while the second included two cabin window cutouts.