The Strength of Thick Cylinders Subjected to Repeated Internal Pressure

Abstract

In April, 1956, the authors presented to The Institution of Mechanical Engineers a paper entitled “Fatigue Under Triaxial Stress: Development of a Testing Machine and Preliminary Results,” and in September, 1956, a supplementary paper was presented to the International Conference on the “Fatigue of Metals.” These papers reported tests carried out on cylinders made from a 2 1/2 per cent Ni-Cr-Mo steel, which were subjected to (up to) ten million repetitions of internal oil pressure of (up to) 45,000 psi. Since the publication of these papers a considerable amount of testing has been carried out on cylinders made from a carbon steel, a 3 per cent chrome steel, an austenitic stainless steel, a light alloy, a nearly pure titanium, the Ni-Cr-Mo steel in a harder state, and both the Ni-Cr-Mo steel and the chrome steel in the nitrided condition. In addition, many tests of more academic significance have been carried out on the Ni-Cr-Mo steel in an attempt to achieve a better understanding of the extraordinary results which have been obtained. This paper is concerned mainly with the presentation of the results (supported, of course, by ancillary tests on each material), which are of importance in design. Points of academic interest are discussed only when they are relevant to the practical problem. In order to make the paper reasonably self-contained, a brief summary of the previous work is given, together with a short description of the machine which has been developed for this work.