Fatigue Behavior and Life Prediction of PI/SiO2 Nanocomposite Films

摘要

In this report, the fatigue behavior and lifetime of Polyimide/silica (PI/SiO2) hybrid films are investigated. To evaluate the fatigue property of this class of hybrid films, the stress-life cyclic experiments under tension– tension fatigue loading with 10 Hz of the frequency are performed, and the stress ratio is 0.1. Dynamic creep and cyclic softening/hardening are analyzed based on the change of hysteresis loops during the fatigue process. The structure-property relations are discussed to further understand their phenomenon and deformation mechanisms. To predict the fatigue life of this class of hybrid films, a semiempirical model is proposed based on fatigue modulus concept. The simulated results are well agreeable with the testing values.