Use of simulations in determination of wheel impact forces P1 and P2 due to rail dip defects

A rail vehicle-track interaction dynamics model has been applied to determine the track vertical dynamic forces due to rail dip defects such as dip joints and welds, which are required in railway vehicle acceptance procedure. The model was validated using the field measurement data of rail dip defects and accelerations of a vehicle axlebox. The simulated dynamic forces – the P2 forces have been compared with those calculated using a well-known formula. Their difference and the formula’s limitation have been discussed. The effects of the rail dip defect and the vehicle speed on the track vertical dynamic force have also been investigated.