Characteristic Analysis Of Impact Problem Between High Speed Wheel And Hadfield Steel Crossing

Railway transportation is one of the most efficient land transportation that known inthe world, Hadfield steel crossing is important equipment on railway lines. With thedevelopment of high speed, heavy load, continuous welded rail of across section ofrailway, higher demand has been asked for the structures and service life of Hadfield steelcrossing. Hadfield steel crossing suffers from huge cyclic loading when it is working, andfatigue spalling appears at the work surface, in the end, the crossing is failed and get out ofrailway lines. Fatigue failure was the main reason for the failure of Hadfield steel crossing,consequently, it has practical significance to perform analytical investigation of crossingimpact that happened in the couse of working so as to improve the work conditions ofrailway crossing, and prolong service life of crossing. Former research of crossing forcebasicly limited to the static analysis, and dynamic force analysis of crossing is very less.In this paper, Monobloc casting Hadfield steel crossing with the number of12andrail of60kg/m was the research object, the reason for failure and failure mode wereanalysed for the first part. Because the Hadfield steel is an alloy steel that has preferablework hardening capacity, work hardening was noticed in surface layer of crossing when isis working. Hardness measurement experiment was performed to study thework-hardening capacity of typical positions on the crossing, and the history of serviceconditions of typical positions on the crossing can be obtained to verify the validity of thedynamic simulation.Finite element code ABAQUS was employed to model the high speed wheel andHadfield steel crossing, and the process of wheel roll over the crossing are dynamicalsimulated. Stress-strain distribution of each position on the Hadfield steel crossing wasobtained. Moreover stress-strain fields under different parameters of axle load and speedwere analysed, and summarizes the influence law of Stress-strain distribution on thecrossing affected by wheel speed, axle load, etc.Combined with metal accumulative fatigue damage theories and knowledge offracture mechanics, reasons of fatigue crack formation and propagation law were analysed, fatigue life formula was derived according to some original formula. Life formulas wereapplied to estimate the fatigue life of Hadfield steel crossing, which provide new ideas forresearch of the development rule of subsurface defects of crossing and predict the fatiguelife of Hadfield steel crossing with small crack in surface layer.