Irregularity model of welded rail joint and wheel-rail dynamic responses in heavy-haul railway

Due to the irregularity of excitation of welded rail joints (WRJs), the dynamic impacting force between the wheel and the rail would be obviously enhanced. According to measured irregularities of WRJs in heavy-haul railway, a modified excitation model is put forward to simulate the irregularity in this paper. Dynamic interactions excited by the irregularities are analysed, including the measured irregularity, the theoretical irregularities obtained from a traditional model and a modified model. Effects of parameters of the modified excitation model on dynamic interaction are discussed. Results show that, compared to the traditional model, the dynamic performances excited by the modified model present better consistency with those due to the excitation of the measured irregularity. Furthermore, with the growth of the depth, the wheel-rail dynamic indices will increase linearly, and they will decrease nonlinearly with the increase of the wavelength.