Mean Shear Stress Effect for a Notch-Free Ductile Material Under Pure Cyclic Torsional Loads

Abstract

The relationship of torque versus angle of rotation stabilizes after only a few cycles so that the alternating stress will become a constant as long as the maximum shear stress is less than the shear yield strength of the material. Using this information in Findley‘s fatigue criterion, it is demonstrated that the mean shear stress has very little influence on the fatigue limit of a notch-free ductile material under cyclic torsional loading.