Investigation of the Fracture of Brittle Bodies Due to Their Contact Interaction with Rigid Dies

We propose a theoretical and experimental procedure for determining fracture conditions of brittle bodies subjected to the action of rigid dies of various shapes. Similarly to the fracture mechanics approach, we specify the stress intensity factors K₁ and K₂ in the vicinity of the die base, which determine the conditions of crack initiation, as well as values of the angle between cracks and the specimen base. It is established that upon the specimen compression by the die, the angle of the inclination of the fracture surface to the specimen base plane remains practically unchanged , which agrees fairly well with the theoretical data obtained. Body fragments have been revealed after pressing dies of different types into specimens: in a shape close to a circular cone for a round die, in a shape close to a quadrangular pyramid for a square die, and in a shape close to a triangular prism for a rectangular die.