Testing methods for fatigue properties of rubber materials and vibration isolators

The main purpose of this investigation was to find out if laboratory fatigue tests in tension give results which can be useful in predicting the service life of a vibration isolator. Four natural rubber vulcanizates with different curing systems were used in the tests. The fatigue life in cyclic loading was determined in tension on standard tensile specimens (dumb-bells) and in shear on two types of vibration isolators. The results indicate that the information achieved in tension is relevant for estimating the service life of an isolator. Both relaxing and non-relaxing tests in tension were made and the relaxing tests seem to give the best correlation between dumb-bells and isolators. As the relaxing tests are also the least time-consuming they are to be preferred for material testing.