ABSTRACT
It is of both historical and technical interest to follow the development of materials for aircraft construction, because in no other situation have the properties of strength, weight, and operating temperature been so interrelated and important. The first all-metal monoplane, designed by Hans Reissner of Germany which first flew in 1912, had wings of pure aluminum. In the early 1930s
Figure 1.2 Materials maturity curve (From Louis J. Sousa, Problems and Opportunities in Metals and Materials: An Integrated Perspective, U.S. Dept. of the Interior, Bureau of Mines, Washington, D.C., 1987.)
riveted aluminum alloy skin was first used for airframe construction and was the predominant fuselage material until the advent of supersonic aircraft. The Boeing 757, for example, contains 80% aluminum, 12% steel, and 3% composites. But aluminum alloys are limited to temperatures of about 175°C. The Concorde, the only supersonic commercial aircraft in use today, and military aircraft such as the SR-71 surveillance aircraft (Mach 3), have titanium alloy fuselages. Starting with the Harrier, an aircraft designed in the 1970s at McDonnel Aircraft Company, much of the aluminum support structure was replaced by lighter and stronger carbon-epoxy composites. Strong, lightweight composites are currently playing a major role in nonmilitary aircraft. The Voyager (Figure 1.3) achieved its global circuit without refueling, in large part due to the use of graphite-epoxy composites in conjunction with honeycomb structures. The Beech Starship Model 2000 (Figure 1.4) is the first all-composite aircraft to be certified by the Federal Aviation Administration (FAA). Predictions are that we will see many more composites in the aircraft of the twentyfirst century, not only in the fuselage and support structures but in the jet engine itself.
