For samples of different sizes and with different stress concentrations tested under stationary and programed loading, there is a single unique fatigue curve, expressed in relative coordinates.
The variation coefficient of the limited fatigue limit of light alloys is independent of the base of the tests.
The dependence of the fatigue-life scatter on the stress level and average fatigue life follows from the equation of the fatigue curve and the normal fatigue-limit distribution law.
The fatigue limits, the mean square deviation of the fatigue limit, and also the sum of the relative fatigue lives depend linearly on the logarithm of the fatigue-failure similarity criterion.
By making use of the properties of the unique fatigue curve and the similarity conditions, we may determine the fatigue characteristics of construction elements by reference to the results of tests on a limited number of samples.