Propagation of fractures from an interface in a Brazilian test specimen

Abstract

The influence of an interface on the initiation and propagation of fractures was investigated using the Brazilian tensile test (diametral compression of a disc). Failure in the Brazilian test takes the form of an extension fracture in the loaded diameter. Various samples with an interface running perpendicular or nearly perpendicular to the diametral axis were tested. The properties of the interface determined the fracture pattern. Failure in the test specimens was simulated using a computer programme utilizing the displacement discontinuity method. The pattern of fractures predicted by the simulation is fairly consistent with that observed in the physical tests. It is shown that slip occurring on the interface is an important mechanism affecting the fracturing process.