Studies on toughened material forms for composite fuselage keel applications

You are here: Homepage > Search

Studies on toughened material forms for composite fuselage keel applications

Grande, D.H. / Aynn, B.W. / Dost, E.F. / Ilcewicz, L.B. / Avery, W.B.

Compressive performance, damage resistance, damage tolerance and the ability to redistribute load at ply drops are among the requirements for composite materials used in the keel section of a commercial transport fuselage. The design drivers for fuselage keel performance and the requirements for composite materials used in keel applications are discussed. Lamina architecture, matrix toughness and resin content were examined for their influence on keel design drivers in a number of screening studies. In studies comparing in the compressive performance of laminates with ply drops, materials with toughened resin-rich interlaminar layers (RIL) showedless compressive strength degradation than materials having untoughened matrices with non-RIL architectures. Studies were performed on one toughened material system with varying resin contents in which compressive ultimate strains were observed to increase with increasing resin content for undamaged specimens, impact damaged specimens and specimens with holes. Materials having increased interlaminar resin content and correspondingly thicker RIL architecture showed improved Mode II interlaminar fracture toughness. Preliminary conclusions from impact damage resistance studies on foam core sandwich construction having toughened and untoughened face sheets are also discussed.