Turner, H. C.
Technical SpecialistChairman of Symposium Committee, McDonnell Aircraft Corp., St. Louis, Mo.
Pages: 2 Published: Jan 1962
Until the past decade, room-temperature data were sufficient for design of most aircraft structures. Present turbojet engine aircraft, missiles, and spacecraft travel at speeds which create heating of the exposed surfaces, especially at the leading edges. High temperatures are also encountered in the vicinity of the power plant. Room-temperature design data are no longer sufficient; data obtained from tests made at elevated temperature are required for design of present high - performance aircraft and spacecraft. From 60 to 90 per cent of an airframe or missile structure must be designed for compression. Most parts are designed so that, if overloaded, failure will occur by elastic instability. A part may also fail by yielding when relatively heavy thicknesses or short column lengths are involved. The compression stress-strain curve provides data that enable the designer to predict failure by buckling or yielding. Many aircraft and missile parts are made from relatively thin sheet metal formed into skins, ribs, frames, webs, and stringers. Compression tests must be made on sheet of the actual thickness used because material properties are a function of processing procedures; a thin sheet will have different compression properties than a heavy section of the same composition. In order to load a sheet specimen without budding, a supporting jig is required. This jig must provide the necessary lateral support without significant friction during compression of the specimen.
Paper ID: STP46988S