There appear to be many papers on FCGR modeling based on the use of low cycle fatigue properties and energy dissipation within a fracture process zone (at least 5 in past 10 years and many before). The latest (2018) appears to be "On the theoretical modeling of fatigue crack growth" Zahra S. Hosseini et al., Journal of the Mechanics and Physics of Solids 121 (2018) 341–362.
Is this really the state of the art? Are there no purely crack mechanics models?