Construction of rail rolling contact fatigue response diagram based on rollingsliding experimental data

In this paper, the construction process of the classical shakedown map in line contact is combed in detail, the inaccuracy of which is pointed out, and the optimization methods of shakedown limit by numerical simulation is summarized. The construction method of the rail rolling-sliding contact fatigue response diagram is proposed in this paper. The objective of this work is to construct a rail rolling contact fatigue response diagram and optimize the classical shakedown map. Rollingsliding experiments were performed to investigate the rail steel rolling contact fatigue (RCF) response behaviours. Firstly, the yield strength values of the selected wheel and rail materials were determined by tensile test. Secondly, according to the region division in the classical shakedown map, taking the friction coefficient (μ) and load factor (P0/k) as the horizontal and vertical coordinate plots, to select different position coordinate plots at intervals to cover the four regions in the classical shakedown map: elastic, elastic shakedown, plastic shakedown and ratchetting. The yield strength value of the rail steel is utilized, the normal load value of rollingsliding experiments corresponding to different coordinate plots were calculated by Hertz line contact, and the rolling-sliding experiments with different friction coefficient were further carried out. At last, after the rolling-sliding experiments, the fatigue damage and wear behaviours of the rail rollers were systematically analysed via scanning electron microscopy (SEM) and electronic balance. On the basis of the fatigue damage results of different forms, the actual experiment coordinate plots were classified into new regions. Further, the rail rolling contact fatigue response diagram is constructed by means of comprehensive consideration of both subsurface damage behaviours and wear rates of rail rollers.