Fatigue Crack Growth Under Spectrum(Random) loading

Dear all Researchers, 

 I am writing regarding for the first time about the UAA(Unified analytical aspect) on Fatigue crack growth. The idea of this technique is this question : too many fatigue life prediction relations but still those are not perfect. on the other hand, new math ways still have not been the classical fracture mechanics. I am looking for some comments as response to this concern. Clearly, how we upgrade fracture mechanics theory using atomistic development in modeling fatigue propagation?

 Let us talk about this.

Regards,

Hadi