ABSTRACT
Understanding fatigue crack growth propagation has become increasingly important in the rubber industry. It has been observed that cracks grow more rapidly from sharp cuts in elastomer materials under stress than is expected from a consideration of the strain energy release rate alone. After the crack has grown, the behaviour returns to the 'steady state' crack growth rate per cycle anticipated for the applied strain energy release rate. The chapter examines these transitions from an artificial sharp crack tip, introduced for example by a razor in a pure shear tear test piece for a range of elastomer materials. It also examines the ability of a finite element analysis package to predict the crack growth path for simple test piece geometries. The chapter presents preliminary results that indicate that the direction of crack growth can be predicted using the direction of maximum strain energy release.
