Numerical computation of wheel-rail impact noises with considering wheel flats based on the boundary element method

When a wheel rolls to a flat, it can generate the impact force several multiples larger than that generated at the common time. The paper established a wheel-rail coupling vibration model with wheel flat, and vibration acceleration responses of the rail was computed. The computational result was then compared with the experimental result. Good consistency between simulation and experiment indicated that the finite element model is reliable. Then, based on the finite element model and boundary element model, the paper established a structural-acoustic coupling boundary element model and computed the radiation noise of wheel-rail under effects of wheel flats. Results show that: the wheel flats were an important reason for wheel rail impact noises, impact noises of wheel flats were mainly concentrated in frequency bands of over 250 Hz, and impact noises of wheel flats were closely related with wheel flat length, quantity of wheel flats as well as running speeds. With the increase of these parameters, the radiation noise of wheel flats would be increased correspondingly.