Influence Of Track Irregularity On Running Safety Of High-speed Train Under Seismic Action

Track irregularity is one of major factors that make trains vibrate, which impacts the safety and stability of high-speed trains more significantly under seismic excitations. Track irregularity is a complex random process, in the simulation of train-track coupled dynamics, it is generally expressed by power spectral density function. So it is very significant of avoiding trains derail that we research the differences of the foreign typical high-speed railway track spectrum and Chinese high-speed railway track spectrum and its influence of the running safety of high-speed trains under seismic excitations.This dissertation mainly accomplishes these works:1. The German low-disturbing spectrum and Chinese high-speed track spectrum density is compared from four aspects. The samples of the two spectra are simulated by trigonometric series method.2. The dimensional model with 31 degree of freedom is built which contains a vehicle body, two bogies and four wheel sets. The equations of motion are derived by Lagrange equation and train-track coupled dynamics model is built.3. The derailment coefficients, rates of wheel load reduction and lateral wheel interaction forces are calculated with the track excitations by German low-disturbing spectrum and Chinese high-speed railway track spectrum, which vary with the train’s speed and seismic intensity. The influence of the two spectra to running safety of high-speed trains under seismic excitations is analyzed.4. The equation of acceleration threshold for train control in earthquake is verified and the influence of German low-disturbing spectrum and Chinese high-speed railway track spectrum to threshold is analyzed. The threshold should be enhanced moderately according to the research.