Suppression of abnormal chattering of a high-speed EMU carbody

A carbody chattering phenomenon accompanied by bogie hunting movement was investigated. The online test results showed that the vehicle at a large tread conicity state exhibited insufficient stability when running at higher speeds, causing the hunting frequency of the bogie to continuously increase and approach the diamond-shaped deformation modal frequency of the carbody, consequently causing the carbody to chatter. To improve the running stability of the vehicle and to suppress the carbody chattering, a two-step progressive optimisation method that combined analytical optimisation and simulation optimisation to optimise the parameters of the anti-yaw damper was proposed. Furthermore, the effect of optimisation was experimentally verified. Results showed that after optimisation, the critical speed of the vehicle under the condition of worn wheel was significantly enlarged, the bogie exhibited no obvious hunting motion, carbody chatter was significantly alleviated, and both the ride quality and the curve passing performance were improved.