Fatigue crack propagation:
If it is assumed that no plastic deformation occurs around crack tip and law of fatigue crack propagation for place of above Example is da/dN = 10- 8 (Δ KI eff )2.0 mm/cycle , find after how many cycles the plate will fracture.
Δ K I = ΔK I eff because there is no plastic deformation in crack tip neighbourhood.
ac = 146.14 mm, ai = 35 mm from above Example .
or, Nf =2´104 ln ( ac/ ai) = 2´104 ln (146.14/35)
or, N f = 2´104 ln (4.175) = 28584 cycles