Effect of Track Stiffness Uneven on Wheel/Rail Impact Load

Based on the formulas of P 1 and P 2 provided by Derby of Britain,the paper performs a calculation of the influence of track stiffness changes upon impact load between wheel and rail when the vehicle passing over 60 kg·m -1 rail joint with the speed of 160 km·h -1 ,with the United Model of Vertical Vehicle-track Systems compared and validated,which indicates that results obtained from formulas and from simulation model are identical.Simultaneously the change of track stiffness affects P 1 very little,but it is great that the track stiffness affects the P 2 impact force.With the increase of total track stiffness,the increasing range of P 2 is much larger than P 1 and close to P 1.Due to the fact the damage caused by low frequency impact load to sub-rail components is more serious,track structure should be designed according to the idea of elastic designing.