The importance of compressive stresses on fatigue crack propagation rate

In this study it is emphasized the importance of the compressive part of the cycle, and of cyclic plastic properties, on crack propagation rate. It is reassessed the inadequacy of crack closure concept and ΔKeff to describe crack propagation rate, at negative stress ratios. It is also verified that models based solely on extrinsic properties of materials, like da/dN−ΔK or da/dN−ΔK (Kmax) should also incorporate intrinsic properties of the materials in order to properly correlate fatigue crack growth.