Further Report on Fatigue Theory of Metals

Abstract

The endurance diagrams indicating the influence of mean stresses on allowable stress amplitudes were obtained for a cast iron under bending and torsional moments, and the theory of fatigue failures reported previously is further confirmed. For fatigue failures of notched test pieces, we propose a new view that the stress concentration factor for fatigue failures is to be determined by the concentration factor of tensile principal strain, which is calculated, using "micro-Poisson's constant", with regards to the principal stresses concentrated due to the notch effect in the direction of the stress.