Stresses near a crack in a rubber sheet

The principal stresses in the vicinity of the crack tip in a rubber sheet have been determined experimentally by measuring the strain field with the aid of an imprinted grid work and calculating the stresses by assuming neo-Hookean material behavior. The principal stresses in the crack-tip vicinity are presented graphically. A correlation between the measured maximum tensile stress on the crack axis and that obtained from infinitesimal-elasticity theory is established. Information is given which provides bounds on the loading and deformation within which a large-deformation elastic analysis is valid before geometric deformations due to tearing must be considered.