A Research On The Fatigue Life Prediction Of Structure Under Vibration Loading

The fatigue failure caused by the vibration of engineering structures is often come forth. According to the frequency of repeat loading, fatigue can be divided into three kinds: static fatigue, vibration fatigue and sound fatigue. Vibration fatigue is that when the frequency of repeat loading is near the freefrequency. According to the loading, the vibration fatigue can further be put into three categories: the vibration fatigue under simple loading, complex loading and random loading. The approaches of life estimation for vibration fatigue are reviewed in this thesis. Aware of the limitation of the approaches commonly used nowadays that they are incapable of estimating fatigue life under the vibration loading of both narrowband or broadband PSD, a new approach for the fatigue life prediction under random vibration is presented based on the mechanism of random fatigue. The process of fatigue life prediction is outlined and a example is given. The results demonstrated that the presented approach can predict the vibration fatigue life under the simple loading, complex loading and random loading, as well as the fatigue life under the loading of both narrowband or broadband PSD.