Criterion on Fatigue Strength and Fatigue Crack Growth Rates in Notched Material Based on the Equivalent Stress Ratio Concept

摘要

Equivalent Stress Ratio, which is proposed as a parameter for correspondence between notched and unnotched fatigue data, is applied to fatigue data concerning torsion, bending and their combination loading. Fatigue strength of a notched specimens is formulated as a function between effective stress ranges at notch roots and equivalent stress ratios. Fatigue crack propagation rates is also constructed based on the equivalent stress ratio.