A cohesive model of fatigue crack growth

We investigate the use of cohesive theories of fracture, in conjunction wit h the explicit resolution of the near-tip plastic fields and the enforcemen t of closure as a contact constraint, for the purpose of fatigue-life predi ction. An important characteristic of the cohesive laws considered here is that they exhibit unloading-reloading hysteresis. This feature has the impo rtant consequence of preventing shakedown and allowing for steady crack gro wth. Our calculations demonstrate that the theory is capable of a unified t reatment of long cracks under constant-amplitude loading, short cracks and the effect of overloads, without ad hoc corrections or tuning.