Accession Number : ADA301716

Title :   Bolt-Bearing Fatigue of a Graphite/Epoxy Laminate.

Descriptive Note : Technical memo.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CEN TER

Personal Author(s) : Crews, John H., Jr

PDF Url : ADA301716

Report Date : JUL 1980

Pagination or Media Count : 27

Abstract : Graphite/epoxy laminates (T300/5208) were tested under bolt-bearing loads for a range of bolt clampup torques and for several test conditions involving water. High clampup torque improved both the static strength and fatigue limit by about 100 percent compared to a simple pin-bearing case, which had no through-the-thickness constraint. The static strength improvement was explained in terms of failure modes. Bolt clampup also influenced the hole elongation that developed before failure. For both the static and fatigue tests, the hole elongations were much larger for the low-torque-clampup case than for the pin-bearing case or for tests with moderate clampup torques. Tests in water degraded static bearing strength only slightly, but reduced the fatigue limit about 40-percent below that for tests conducted in air.

Descriptors :   *BEARING STRENGTH, *EPOXY LAMINATES, *BOLTS, *GRAPHITE EPOXY COMPOSITES, WATER, STRENGTH(MECHANICS), LIMITATIONS, EPOXY COMPOUNDS, FAILURE(MECHANICS), STATICS, TORQUE, FATIGUE TESTS(MECHANICS).

Subject Categories : Metallurgy and Metallography
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE