The application of dither to mitigate curve squeal

Curve squeal is a highly disturbing tonal sound generated by rail vehicles like trains, metros or trams, when negotiating sharp curve. The probability that occurs increases with reduced curve radius of the track. noise attributed to self-excited vibrations caused stick/slip behaviour due lateral creepage wheel tyre on top rail. With respect large number rolling stock units and long lifetime vehicles, there an urgent need for cheap simple retrofitting measure reduce squeal. Therefore, main objective this paper investigate potential means active control in form dither efficient robust way. Dither has been applied field mechanical engineering systems including non-linear components. There it shown suppress oscillations very efficiently. open-loop control. It consists adding forced vibration vibrational system. A time-domain model mechanisms behind leading at squealing rig Chalmers University Technology. analysis showed, presence constant friction, coupling between vertical direction driving mechanism building up vibrations. Based insight, investigated. For case considered here overall kinetic energy more than 10 dB 20 dB. Further optimisation forces radiated power might increase potential.