Advanced Structural Concepts

Specific mechanical properties of fiber-reinforced composites have made them an attractive material for application to many aircraft structures. Today, composite structure is typically made up of laminated layers (plies) of 2-D composite material with the fiber direction of each ply thoughtfully oriented to optimize structural efficiency. The goal of 'continued improvement' in structural efficiency and cost has inspired the development of a new and innovative structural concept. This concept is to automatically weave complete composite laminate preforms that are made up of optimally oriented discrete plies held together with an optimum density of Z-directional (thru-the-thickness) fibers. This concept, once developed will improve the interlaminar shear strength, damage tolerance, and fabrication cost of continuous fiber reinforced composite structure. Development of this concept will eliminate the manual cutting, placement, and debulk (typically ever four plies) of the thin (.005" to .014" thick) composite plies. Additionally, this concept will increase the interlaminar shear and damage tolerance of the structure with minimal impact to in-plane properties by introducing an optimum density of Z-directional fiber. Bally Ribbon Mills in conjunction with Lockheed Fort Worth Company as subcontractor will evaluate the feasibility of this technology and its application to fighter aircraft mid-fuselage structure.