Non-Relaxing Crack Growth and Fatigue in a Non-Crystallizing Rubber

Abstract

Abstract The crack growth behavior of a non-crystallizing rubber, SBR, is investigated in terms of the tearing energy T, the energy available for crack growth. For cyclic deformations in which the minimum tearing energy is zero (relaxing conditions), a unique relationship is obtained between the growth per cycle and T at the maximum deformation. This rubber also exhibits crack growth at constant tearing energies. The relationship of the crack growth rate as a function of tearing energy, when the minimum tearing energy of the cycle is not zero, can be superimposed on the relaxing relationship by scaling the rates, and a tentative explanation is proposed for the scaling factor. Fatigue data are consistent with this.