Modelling of spall formation in a plate made of austempered ductile iron having a subsurface-edge crack

Analysis of crack initiation and propagation under moving loads is a complex phenomenon due to the non-uniform state of stress and singularity at the crack tip. A subsurface crack subjected to moving compressive and tangential loads grows toward the surface and leads to the formation of a sheet-like wear particle. The normal and shear stresses arising at the crack tip due to normal and tangential loads can be characterized by the mode I and II stress intensity factors, KI and KII, respectively. In this study, the behaviour of a subsurface-edge crack subjected to moving normal and tangential loads was analysed by the finite element method. The problem is considered under the linear elastic fracture mechanics theory. KI and KII stress intensity factors at the crack tip are computed for different load positions and different load application angles. The plate is considered to be made of austempered ductile iron which is used as the base material in rolling-sliding contact conditions. The analysis applies linear elastic fracture mechanics and finite element modelling to predict spall formation in the elastic state.