Study On Evaluation About Ride Comfort Of High Speed Railway Line Based On The Virtual Track Geometry Technology

With the increasing of operation speed and mileage for high-speed railway, the riding comfort of high-speed railway has already become the main problem for railway administrative department. The statistical analysis on the long-wave track longitudinal irregularity for high-speed railway (whose wavelength is below 120 m) which exceeds the limit has been done by the railway department. It has been found that the over-limit location occurs near the vertical curve of vertical section. According to the related experiences about high-speed railway operation, the long-wave track longitudinal irregularity has a very prominent effect on the comfort and stability of high-speed motor train units. Consequently, from the perspective of track irregularity, to explore the riding comfort of the alignment of the cross and vertical section has the extremely important theoretical and practical value for high-speed railway lines.In this thesis, referring to the parameters of CRH2A EMU, the vehicle-track dynamic simulation model was established. Based on this model, the vehicle acceleration, the vehicle-axle box relative displacement and the flange-rail relative displacement were extracted. Based on the principle of inertial method for track geometry car, by means of the quadratic integral of acceleration and the high-pass filter, the equivalent track longitudinal and alignment irregularities of the high-speed railway were obtained. Through the analysis above, the virtual track geometry car technology based on the principle of inertial method was proposed.The virtual track geometry car technology was tested on trial at the straight line section, vertically curved section and plane curve section respectively. The equivalent track longitudinal and alignment irregularities at the straight line section correspond well to the excited irregularities on wave shape and standard deviation curves as well as in power spectrum density charts. The equivalent irregularities at the vertically curved section have a large fluctuation near the straight-curve dot and the curve-straight dot, which also results in the long-wave irregularities. Due to the transition of the easement curve for the plane curve section, the fluctuations of the equivalent irregularities near the straight-ease dot, the ease-curve dot, the curve-ease dot and the ease-straight dot are less than those for the vertically curved section.The influences of alignment parameters including vehicle speed, the gradient, radius and length of vertical curve, the length of straight line between two vertical curves, the radius of plane circular curve, the length of easement curve, the length of intermediate straight line indexed by wave shape, standard deviation and power spectrum density on the equivalent irregularities were analyzed.