Characteristic Tearing Energy and Fatigue Crack Propagation of Filled Natural Rubber

Below the incipient characteristic tearing energy (T(0)), cracks will not grow in rubber under fatigue loading. Hence, determination of the characteristic tearing energy T(0) is very important in the rubber industry. A rubber cutting experiment was conducted to determine the T(0), using the cutting method proposed originally by Lake and Yeoh. Then, a fatigue crack propagation experiment on a edge-notched pure shear specimen under variable amplitude loading was studied. A method to obtain the crack propagation rate da/dN from the relationship of the crack propagation length (Δa) with the number of cycles (N) is proposed. Finally, the T(0) obtained from the cutting method is compared with the value decided by the fatigue crack propagation experiment. The values of T(0) obtained from the two different methods are a little different.