Metallic materials fatigue behavior: Scale levels and ranges of transition between them

Abstract

The metal fatigue behavior is analyzed on the basis of the multi-scale description of damage accumulation processes in direction of increasing scales (from micro- to meso- and macroscopic scale levels). The governing mechanisms in the damage accumulation process peculiar to each scale level are considered. The transitions between scales are realized gradually within the ranges with the bimodal distribution of fatigue life. Statistical analysis of data on mechanical characteristics defined in monotonic tensile and fatigue tests for aviation structural materials based on Fe, Al, Mg, Ti, Cu, and Ni have shown that for most alloys the three scale levels are exhibited in the direction of the stress level increasing.