Investigation of the influence of defects on CT specimens fatigue crack threshold

Abstract

The object of the performed investigation is the resistance of spheroid graphite cast iron with shrinkage voids to fatigue crack propagation. The range of stress intensity factor Delta K quantities obtained for compact tension (CT) specimens containing shrinkage voids compared to specimens without voids and void influence on stress intensity factor distribution in CT specimen is investigated using different computational methods based on linear fracture mechanics. The limit stress intensity factor, experimentally obtained at da/dN = 10(-10) m/cycle and lower, is compared to stress intensity factor obtained using the finite element method simulation results. Void influence on crack propagation is analyzed.