The objective of this research is to develop a simple and reliable accelerated life testing technique to predict the service life of structural polymer components under fatigue loading conditions. The temperature, aging time, and solvent concentration induced shift behavior of viscoelastic material functions of polymers will be utilized to accelerate the fatigue tests. Experiments under cyclic loading will be performed under loading frequencies that are higher than in-service frequencies at elevated temperatures to accelerate the time scale. Two different sets of tests, linked by a free volume based theory, will be performed: (1) short term accelerated tests at modified environmental conditions and at higher frequencies in loading; and (2) long term experiments that are conducted over long periods of time to simulate realistic loading conditions in practical applications. The results from these two sets of experiments will be analyzed and compared to facilitate the development of and validation of a reliable experimental life-testing technique. The practical significance of this research will be the provision of a simple accelerated life testing technique for industries that manufacture or use polymer components under variable amplitude fatigue loading conditions.
