Brittle cone fracture in contact boundary

摘要

The problem of fracture of a brittle material such as glass when subject to indentation by a relatively rigid, cylindrical square-ended punch is considered, using classical energy principles. The strain energy needed to form an embryo cone crack adjacent to the punch edge is found, and from this the load needed to initiate fracture given. The calculation is of practical interest in the interpretation of classical brittle indentation tests, and also in the design rating of bearing blocks supporting structural glass.