An experimental method for evaluating SIF distributions during crack turning in non-brittle materials

After briefly describing an experimental modelling method consisting of a marriage of frozen stress photoelasticity with the Griffith–Irwin equations of fracture mechanics, the method is applied to a generic motor grain model containing part through cracks emanating from the corner of a fin tip under internal pressure to determine approximate crack shapes and stress intensity factor values at maximum crack depth for various penetration depths. The role of shear modes during crack turning is described.