Probability Of Fatigue Life Prediction Method And Reliability Analysis

Many outstanding researchers have studied fatigue failure deeply one after anothersince people realized this phenomemon in mechanical operation, and fruitful results areachieved. Along with the development of modern science and technology, mechanicalstructure are also under severe test, first one is the complication and the improvement ofaccurate and sensitive of mechanical structure, the improvement of the performance ofthe second is bad working environment and harsh operating conditions, secondly theoperating environment is brutal and the operating condition harsh. These factors madeus have new awareness of fatigue failure study. Researchs have proposed variousfatigue failure mechanism and study method based on different failure factors, and thefatigue life of component was predicted. Some anti-fatigue design and fatigue lifeprediction methods were proposed in the process of fatigue failure study. The lifeprediction of material(or structure) was divided into two different kinds: deterministicand uncertainty fatigue life prediction, because of some uncertainty factors, and thesetwo kinds methods are popular study of modern fatigue failure theory and life prediction.But these methods are based on Miner principle and have their own range of application,the results will be wrong if the application is out of the range. This paper clearlyanalysed the fatigue failure and life prediction methods of material (or component),pointed out the limitation of different methods; studied the effect of uncertainty factorsin fatigue damage on fatigue failure and life prediction by using mathematicalprobability distribution and statistical theory, and dealed with these uncertainties by acertain quantitative method, thereby further understanded the mechanism of fatiguedamage and fatigue life analysis of the material (or component) and the error of testvalue. And thus made a contribution to seeking a fatigue failure criterion and lifeprediction method which can be widely used in engineering practice.By studying thefatigue damage of component material under different load order, this paper found thatthe fatigue limit of material will change in different load condition. And the change wasapplied in material fatigue damage, that is fatigue life prediction, by choosing differentmembership function,the change was quantified, and a better solution was achieved. This illustrated the objective existence of the change.Finally, the paper mainlyintroduces the stress-strength interference model. Several methods of reliability designis given. Finally, the paper mainly introduces the stress-strength interference model.Several methods of reliability design is given.