A uniaxial tensile behavior based fatigue crack growth model

Metallic components fail mostly due to fatigue cracks, and thus a suitable non-destructive detection is necessarily planned to ensure the operation safety. Among the requisite parameters, a fatigue crack growth (FCG) model might be the most important input, which is frequently acquired from well-defined and expensive fracture mechanics experiments. By correlating the uniaxial tensile properties (UTP) with cyclic plastic parameters and developing a unified fatigue crack closure factor U suitable for broad stress ratios, a novel FCG model of improved LAPS (iLAPS) was formulated in terms of linear damage accumulation and Rice-Kujawski-Ellyin field. Results show that the newly-developed iLAPS model can simulate the entire crack growth region as like modified NASGRO does. For open-reported structural materials available with both UTP and FCG data, it is found that current iLAPS predictions are well agreed with experimental results and are also better than original LAPS.