No abstract

No abstract

IT is well known that many materials, including wrought and heat‐treated duralumin‐type alloys, when subjected to fatigue tests in machines employing different stressing and straining actions, may give consistent results under each set of conditions, but the results will not agree from one set of conditions to another. Differences in the form and size of the test piece may also have an effect on the results of fatigue tests. This note discusses certain aspects of the problem of why such differences in test conditions can cause differences in the results of fatigue tests.