Mixed mode fracture in epicycloid specimens II. Point force loading

method of complex potentials is used to obtain an analytical solution for the stresses in epicycloidal specimens due to point force loading. The solution is used to obtain an analytical expression for the stress intensity factors of cusp-like cracks in such specimens which can be considered as a generalization of the well-established concept of Griffith cracks. It is shown that by suitable positioning of the point forces negative mode I stress intensity factors will result. This illustrates the potential of epicycloid specimens for the determination of fracture properties under compressive loading where frictional contact of the crack surfaces is a priori avoided. 0 1997 Elsevier Science Ltd.