Improvement of fatigue life of an aluminum alloy by overstressing /
Fatigue tests were made on some 1.375-inch-diameter and 0.300-incgh diameter specimens of a 17S-T aluminum-alloy rod. One test of a large specimen was run continuously to failure at a maximum stress of 22,000 pounds per square inch. The same nominal maximum stress of 22,000 pounds per square inch wa...
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| Format: | Government Document Book |
| Language: | English |
| Published: |
Washington D.C. :
National Advisory Committee for Aeronautics,
1942
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| Series: | Technical note (United States. National Advisory Committee for Aeronautics) ;
857 |
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| Summary: | Fatigue tests were made on some 1.375-inch-diameter and 0.300-incgh diameter specimens of a 17S-T aluminum-alloy rod. One test of a large specimen was run continuously to failure at a maximum stress of 22,000 pounds per square inch. The same nominal maximum stress of 22,000 pounds per square inch was used throughout the two tests and the load on the fatigue machine was lowered accordingly after the removal of each surface layer. As each test progressed the stress in the metal of the final surface area therefore was increased after the removal of each surface layer. Because of the stresses used, this metal was overstressed, that is, stressed above its endurance limit. All the remaining specimens were subjected to similar overstressing conditions but no metal was removed and a low initial stress was increased periodically to a final maximum value of 22,000 pounds per square inch as each test progressed It was found that the fatigue resistance of 17S-T aluminum alloy can be increased by moderate overstressing. Apparently the increase in fatigue lift obtained in the tests of specimens from which layers were removed was the result of overstressing rather than from the removal of damaged surface layers |
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| Item Description: | NACA TN no. 857 "August 1942." |
| Physical Description: | 11, [3] p. : ill., tables ; 27 cm |
| Bibliography: | Includes bibliographical references |