Fatigue Behavior Analysis and Durability Evaluation of Plastic Fuel Tank

Plastic materials are often used for automotive fuel tanks today because of their light weight, freedom for forming complicated shapes and corrosion resistance. Fatigue behavior of the high-density polyethylene applied to fuel tanks was analyzed under low-level cyclic loading that simulated fuel tank pressure changes. The correlation between fatigue life and stress, temperature and frequency (the major influencing factors) was expressed quantitatively using fatigue test data for test pieces. This expression was then verified in fatigue tests conducted on plastic fuel tanks. The validity of this equation for predicting the fatigue life of plastic fuel tanks was thus confirmed.