FATIGUE OF METALS UNDER NONUNIFORM STRESSED STATE. PART 2. METHODS OF THE ANALYSIS OF RESEARCH RESULTS

摘要

In Part 1 [1] we discussed the stressed state assessment methods and the results of investigation of fatigue strength of nonuniformly stressed structural components.The methods that allow for the influence of stress nonuniformity on the fatigue characteristics of metals and alloys can be divided into the following groups: (i) empirical methods, where the effect of the stress gradient is considered through a simple analytical description of the observed fatigue behavior or by introducing a stress gradient into the available formulas of the material limiting state, and (ii) the methods that derive the influence of stress gradient from the general approaches to the description of the fatigue failure pattern. The above-mentioned methods are based on the consideration of the difference between nominal and effective stresses, heterogeneity of material properties by using the statistical theories of strength and averaged stresses in the surface layer.