A Simple Method for Measuring Tearing Energy of Nicked Rubber Strips

A convenient test configuration for measuring critical tearing energy of rubber is to pull thin nicked strips of the rubber in extension. In the past, methods of measurements employed for this configuration are based on concepts which obtain “tearing energy” through differentiation with respect to the crack length. As a consequence, measurements have to be made on several identical specimens having different crack lengths. This paper describes a simple method based on the J-integral which requires no differentiation and calculates the tearing energy from measurements made on one specimen only. This allows an efficient use of test material and reduces the complexity of critical tearing energy measurement.

Implementation of the J-integral method is illustrated on the uniaxial stretching of a nicked rubber strip. The accuracy of results obtained is found to be comparable to that obtained by existing methods.