The Study Of The Vibration Of Train Based On Random Track Irregularities

Track irregularity is the main excitation of the vibration of vehicle-track coupling system,therefore, it is necessary to study track irregularity and its influence. This thesis studies trackirregularity and the viberation response of the vehicle from three aspects, they aresummarized as follows:1. Track irregularity can be regarded as a stationary random process, its mean is0. thepower spectral density function is the main tool for the frequency domain analysis of randomprocess. By writing MATLAB programs, rendering all typical track spectrum curves. withwhich directly analysising and comparing the similarities and differences between Chineseexisting high-speed track spectrum and abroad typical track spectrums. The results show that,China railway track’s shortwave irregularity is poor, overall between USA grade five andgrade six line spectrum, there is a certain gap with the German track spectrum.2.From the power spectrum estimation theory, presents triangular series method and thediscrete Fourier transform method, programs are written in MATLAB, these two methodswere used for the same power spectral density function, then the time-domain samples areaccquired. The results show that, samples in time domain simulation of two methods areconsistent with the actual situation, the simulation accuracy of discrete Fourier transformmethod is higher than that of the trigonometric series method.3. Discussed the basic assumptions and simplification principles of the train multi-bodydynamics simulation model, the Rail module of dynamics simulation software ADAMS isused to simulate different conditions, such as smooth track and the track with irregularity,straights and corners, vertical and horizontal irregularities etc. Draws the followingconclusions:1) Track irregularity is the main incentive vehicle track dynamic interaction of wheel/rail dynamic role, had a significant effect.2) The train traveling in the corner, the lateral contact force between wheel and rail,lateral acceleration of the vehicle will increase significantly, and the shock will increase.3) The lateral acceleration and the vertical acceleration are mainly contributed by verticaltrack irregularity excitation, the latertal track irregularity excitation has little effect onvibration characteristics of vehicle body.4) The vertical acceleration of vehicle body, lateral acceleration, vertical wheel railcontact force and reduction rate of wheel load index increased gradually with the increase ofthe train speed; the derailment coefficient and lateral contact body force had significant fluctuations with the speed growth.Finally, wavelet analysis method is used to analysis the vertical acceleration of the train,the application of wavelet analysis in some fields is discussed, such as the track maintenance,evaluation of the track, the train running status analysis,and related research or design.