Fatigue Testing and Analysis of Results

Book excerpt: Fatigue Testing and Analysis of Results discusses fundamental concepts of fatigue testing and results analysis. The book begins with a description of the symbols and nomenclature selected for the present book, mainly those proposed by the ASTM Committee E-9 on Fatigue. Fatigue testing methods are then discussed including routine tests, short-life and long-life tests, cumulative-damage tests, and abbreviated and accelerated tests. Separate chapters cover fatigue testing machines and equipment; instruments and measuring devices; and test pieces used in fatigue testing. The factors affecting test results are considered, including material, types of stressing, test machine, environment, and testing technique. The final two chapters cover the planning of test programs and the presentation of results. Test program planning involves the statistical design of a test series; specification and sampling of test pieces; and choice of test pieces, testing machines, and test conditions. The chief purpose of most fatigue tests is the experimental determination of the relation between the endurance and the magnitude of the applied stress range for the material and the specimen under consideration, and final results can be condensed into a table, graph, or analytical expression.