Study On Several Active Control Techniques Of Rail Corrugation

China’s urbanization has made great achievements,and the development of the urban public transportation has kept up with the pace,but the rail corrugation has not been completely solved,up to now.When the vehicle runs through the rail corrugation,the vertical force of the wheelset will fluctuate,and the wheel-rail system will produce jarring running noise.In some serious cases,rail corrugation even leads to traffic accidents such as overturning of the vehicle.The current measures for the rail corrugation are to remove the existing corrugation,such as by grinding rail,etc.Although this method can remove the rail corrugation in a short time,the recurrence rate of the rail corrugation is high and the reproduction time is short.So it has consumed a large amount of maintenance resources.Based on the friction self-excited vibration causing rail corrugation proposed by Professor Guangxiong Chen,this paper studied rail corrugation,from the perspective of the vehicle dynamics and finite element analysis.（1）Using the vehicle dynamic analysis software SIMPACK,the author established a subway B-type model to study the contact position and creep force saturation when the vehicle negotiates through different curved track.The simulation result shows that when curve radius of tracks is less than or equal to 400 m,the creep forces of the inner and outer wheels of the leading wheelsets are saturated,and the creep force saturated extent of the inner wheel is higher than that of the outer wheel.The friction-induced self-excited vibration of the inner wheel-rail system is more likely to appear,thus,rail corrugation is prone to occur,which is consistent with the actual rail corrugation phenomenon in railway lines.（2）Based on the working condition of the vehicle passing through the trach with a radius of 350 m,the author established the ABAQUS finite element model and made simulation calculation of the model.The main vibration frequency of 502.32 Hz was obtained,which will produce a short wavelength corrugation.The effect of damping rings on rail corrugation was studied.The study result shows that the damping ring wheel can effectively reduce the occurrence of rail corrugation.Based on this,the influence of damping ring material coefficient,damping ring installation positions and design sizes of damping rings were further studied.The results show that when the value of damping coefficient of damping rings is greater than or equal to 10^-4,the wheel-track system has a strong ability to suppress rail corrugation.The damping ring system installed on both sides of the wheel has the best effect on the suppression of rail corrugation.The design size of damping rings has a little effect on rail corrugation.（3）The influences of the structural parameters of the wheel-rail system on rail corrugation were studied,including the geometry of the wheel spokes,the track vibration absorber,the vertical stiffness of the rail-sleeper,and the force period acting between the bogie and wheel axle.The study results show that the shape of wheel spokes has a great influence on the frequency and the occurrence trend of rail corrugation,and the anti-S spoke wheel can better suppress the occurrence of rail corrugation.The unstable vibration frequency of 270 Hz can be induced by adding a track vibration absorber.Increasing the vertical stiffness of the rail and sleeper can reduce the trend of rail corrugation.（4）Based on ABAQUS and PYTHON,the author proposed a method to add irregularities to the surface of the rails in the finite element model.Firstly,the finite element single wheel model was established,and the dynamic simulation of the model was carried out.The vertical acceleration of the rail was recorded.The model was verified by comparing the result of the power spectral density analysis of the rail vibration with the exciting frequency of 111 Hz and222 Hz.The analysis simulation shows that when the wheelset passes through the rail with irregularity of different frequencies,the rail vibration corresponding to the excitation frequency will be generated.It verifies the feasibility of the irregularity input method proposed by the author.