Study On Probability Method Of Multiaxial Fatigue Life Model

Many mechanical parts and components in service are subjected to the multiaxial load. Unaxial fatigue theory is not satisfied with the requirement of the design, especially the mechanical parts toward the large-scale, complex structure and the use of complex conditions. The study of multiaxial fatigue has very important theoretical significance. Multiaxial fatigue life prediction is an important aspect in the study of multiaxial fatigue. The result of multiaxial fatigue life prediction is usually the life limit, or the determine amount of injury with traditional methods. But due to various reasons, the fatigue life is not a definite value, and there are certain probability distribution characteristics.This paper studies the relations of the damage between different material planes under multiaxial load, and the damage parameter is defined according to the relations of the multiaxial fatigue damage. Secondly, research the probability characteristics of material fatigue performance parameters through probability analysis and testing method, and the relationship between the accuracy of material parameters and the size of test sample. The accuracy of material parameters can be controlled depending on the design of the test, which can improve the accuracy of life prediction model. The probability characteristics of the material parameters can be obtained through material parameters randomized. Finally, a multiaxial fatigue life prediction model is established, and the distribution of the fatigue life is predicted through Monte Carlo random sampling methods combined with the multiaxial fatigue life model.Probabilistic method is applied to the study of multiaxial fatigue life prediction. The distribution of the multiaxial fatigue life can be predicted through the probability analysis of the multiaxial fatigue. Which is very important significance for the objective reflects of the fatigue behavior and reliability Analysis.