On the Endurance Limit of a Round Bar with Longitudinal Grooves

摘要

In a previous paper, we reached a consideration that the endurance limit of a material should be determined by the amount of the mean stress in a certain area around a point, instead of the stress at the point, and the extent of the area is determined for several kind of metals, by using the results of tension‐compression fatigue tests. In this paper, the extent of area where the mean value of stress to be taken, is determined for a mild steel in another way, viz., by a torsion fatigue test, and we reached the conclusion that the extent of area chiefly depends on the kind of metal and independent of the course of the experiment.