Analysis of dynamic response of vehicle rail under the combined action of flat scar and uneven subgrade settlement

Uneven settlement of roadbed and flat scar of wheel are the main diseases of railway vehicles in operation, which have obvious influence on the dynamic response of wheel-rail system and traffic safety. In order to study the influence of two kinds of diseases on traffic safety, a vehicle-track coupling dynamic model was established, and the dynamic response of the vehicle-track system was discussed under the conditions of different settling wavelength, amplitude, speed and length of flat scar. The results show that the impact response of flat scar has great influence on the vertical force of wheel and rail and the load reduction rate of wheel weight, and the amplitude and wavelength of subgrade settlement have great influence on the vertical acceleration of vehicle body. When the train runs at 100km/h, it is recommended that the wavelength of uneven subgrade settlement is greater than 10m, the amplitude is less than 10mm, and the length of flat scar is less than 40mm.