A threshold fatigue crack closure model: Part II – experimental verification


Correspondence: J. A. Newman. E-mail: john.a.newman@larc.nasa.gov


Predictions from an analytical model that considers contributions and interactions between plasticity, roughness, and oxide induced crack closure are presented and compared with experimental data. The analytical model is shown to correctly predict the combined influences of crack roughness, oxide debris, and plasticity in the near-threshold regime. Furthermore, analytical results indicate closure mechanisms interact in a non-linear manner such that the total amount of closure is not the sum of closure contributions for each mechanism.