Assessment of Materials for Fuselage Panels Considering Fatigue Behavior

Abstract

Minimum-weight designs are frequently too costly to manufacture, whereas less expensive and easy to fabricate and assemble designs are often much heavier. The most efficient design on the basis of both cost and weight often lies between these two extremes. The current trend in structural materials selection consists of the extensive use of composite materials in the airframe. Composite materials have high specific strength, are less prone to fatigue crack initiation and provide enhanced flexibility for structural optimization compared to the aluminum alloys. On the other hand, aluminum alloys display higher toughness and better damage tolerance in the presence of defects. A simple methodology for the weight assessment based on the specific weight for different damage scenarios for an exemplary, simplified fuselage panel, will be presented, in order to quantify the savings under different conditions. The results show that the composites have advantages over the aluminum alloys, although due to low ductility, in parts that are exposed to external damages the aluminum alloys can have better performance due to the better damage tolerant properties.