Abstract
In order to study the fatigue failure mechanism of vulcanieates, scission of rubber molecules, initiation of surface crack, and role of critical crack under uniaxial repeated constant stress have been investigated for pure and carbon black filled rubber vulcanizates. It is found that the fatigue failure of vulcanizates is caused by the instability of the system when the crack which is formed or grown by the propergation of fracture energy generated by the fracture of localized rubber clusters under repeated stress exceeds a certain critical size. If the above condition is not fulfilled, the system is estimated to repeat the redistribution or balancing of stress, the changing of its higher order structure, and the internal fracture without macroscopic failure.
