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The possibility of fatigue crack propagation in the region of compression stresses is considered. After each semi-cycle of cyclic loading the stress-strain distribution near the tip of the crack is determined by the finite element method. It is shown that maximum of the tension stresses increases in the region of compression. The obtained results allow to present the possible ways of the above-mentioned fatigue crack propagation.

Research the fatigue crack initiation and the fatigue crack growth in rail with thermomechanical damage. On basis of cyclic test and numerical simulation of rail deflected mode was determine a fatigue failure characteristics and fatigue crack growth characteristic in rail steel.

Data on corrosion fatigue damages of a sole of rails (defect 69) on the railroads of Russia are submitted. It is established that 69 the corrosion fatigue resulting from moistening of a sole in a zone of contact with subrail laying in combination with the high level of the stretching tension in a rail sole is the reason of breaks of rails on defect. The analysis of statistical data on refusals of rails on defect 69 in the West Siberian management of infrastructure showed that failure rate grows to an operating time of the tonnage of 800 million t gross and has fatigue character. On sites of a way with a complicated plan and a profile failure rate is 3 - 4 times higher, than on quiet Trans-Siberian to the course. Results of the analysis of data are shown and measures for increase of reliability of the rail lashes having tendency to formation of defects on a code 69 are offered.

In research consider a methodology the remaining life assessment of rail with fatigue crack in lower flange. Obtain the stress intensity factor equations for crack size and kind of stress: bending stress, thermal and residual stress. Make up an fatigue strength analysis of rail P65 and under different conditions of loading and remaining life calculation of damaged rail when given conditions of loading. Submit a assessment evaluation rail reinforcement in cyclic crack growth rate.