Effects of R-Ratio on Crack Initiation at External Discontinuities in Autofrettaged Cylinders

摘要

Experimental work shows the effects of positive stress ratios, or tensile minimum stress, during the fatigue cycle on the fatigue crack initiation from holes. This simulates the effect of the residual tensile stresses at the outside surface of autofrettaged cylinders. S-N (stress life) curves and modified Goodman diagrams are shown for fatigue crack initiation.