Bifurcation diagram for in-service fatigued metals

The synergetics concept used for unified description of metals behavior for in-service fatigued aircraft structures. The metals evolution has considered as cascade of bifurcations in self-organized manner of energy adsorption having strongly expressed order in sequence of changing under wide range of multi-parametric cyclic loads interactions. Introduced bifurcation diagram for fatigued metals is plotted and described as a cascade of transitions in damages accumulation from nano to macro scale levels because of cyclic stress level increasing. It is shown that minimal energy consumption for metal fracture corresponds to the nanoscale level, metals behaves as a partly closed system forming subsurface area of crack nucleation. The twisting manner of metals deformation and cracking under local volume compression subsurface in hydrostatic case directed to create first smooth facet, which is area of origin. Then cracking develops out of this facet. Next stages of material cracking for stress level increasing take place in the sequence on meso- and macro-scale levels, metals behave as an open system and their durability is depended on the surface state and their processes of energy exchanging with environment. The phenomenon of the fatigue crack subsurface origination in blades of aircraft components for Very-High-Cycle-Fatigue area also discussed and this phenomenon explains on the bases of the introduced bifurcation diagram.