Prediction of Stress-life Curve of a Material under Random or Cyclic Loading with Asymmetry

Estimation of structures fatigue life under dynamic loading remains an unexplored area in the field of mechanical engineering. Accounting the asymmetry under operational loading is one of features of durability computation for a part of a structure. Common methods of asymmetry considerations result in significant errors in the lifetime of computed structures. This paper describes the methodology approach that allows to predict a fatigue curve for any asymmetry coefficients using the results of a limited number of tests with symmetry and asymmetry under random or cyclic loading. This approach is based on the experimental results of the herein presented research. The scattering signature of the material is necessary for fatigue probability calculations. The methodology also presents the recipes for prediction of fatigue curve and scattering signature with the given asymmetry coefficient and given probability of failure.