Research On Simulation And Analysis Of Typical Track Spectrum

With the improvement of the train speed and the fast development of High-speed and heavy rail, the dynamic Interaction between trains and track structure is increasing, at the same time, the problems of road safety and traveling comforts become serious. Track irregularity is the major reason of vertical vibration for the operating rail vehicles and the disturbance function of vehicle-track system. By the shock disturbance of the track irregularity, Vehicles-orbit coupling system will produce random vibration. The random vibration impactes the passenger comfort and a smooth delivery of goods, On the other hand, it affectes the fatigue failures and reliability of the structural components. Power spectrum density can reveal statistical characteristics and laws of irregularity for a certain track from the amplitude and wave length.To the new rail vehicles, when they are in dynamic simulation and parameters optimization design, as well as in dynamic performance prediction on Physical test-bed, both need power spectrum density as a function of shock disturbance. In our country, as a result of the measured track spectrum can not be directly applied to the vehicle dynamics calculation and test-bed trials, tests and calculations can only use the American and Germany track spectrums. However, the Europe and the United States track spectrums can't characterized our track state well, so it is meaningful to in-depth study the similarities and differences between chinese track spectrums and other countries'typical track spectrums.The thesis studies Chinese existing track spectrum from two angles. The first angle uses Matlab softwareis'M programming and makes use of Matlab graphics rendering capabilities drawing the typical track spectrum curve , with which directly analysising and comparing the similarities and differences between Chinese existing high-speed track spectrum and abroad typical track spectrum. The second angle is establishing the vehicle- track system dynamics model with ADAMS/Rail dynamics simulation software and Comparing vehicle- track system'dynamic responses, which indirectly reflects the difference between the existing high-speed track spectrums in China and other typical track spectrums abroad. The thesis'main contents and conclusions are summarized as follows: 1,Through summarizing information of a variety of literatures, analysised research status of national and international track sectrum.classified the track irregularities. According to the meaning of the power spectrum density, researched on track irregularity power spectrum map deeply. Summarized national and international typical track spectrums models, prepared corresponding simulation program with Matlab language and then drew the varities of power spectrum density curves, by which introduced the track spectrums'characteristics.2,The track spectrums are devided into the general lines spectrum and high-speed line spectrum by suitable speed in order to make a comparative analysis.track spectrums are converted to a unified orbital parameters modeles. Then use Matlab softwareis'M programming and makes use of Matlab graphics rendering capabilities drawing the typical track spectrum curve. From the two perspectes of Track direction irregularities and vertical track irregularities, analysising and comparing the similarities and differences between Chinese existing high-speed track spectrum and abroad typical track spectrum.3,Introduced time-frequency conversion principle,methods and procedures of four typical numerical simulation methods. Take American sixth irregularity power spectrum as an example. Under the premise of the same time parameters, spectrum density parameters, as well as the samples, this thesis simulated track irregularity function of time-domain samples with four typical method respectively, drawed the time-domain sample curve, and used Fourier transform (FFT) method to calculate the power spectrum simulated value. Through a comparative analysises to the simulation results, we find that based on the frequency domain power spectrum equivalent method has the advantages of easy, high-precision simulation and the results can be expressed by functions.4,The thesis prepared simulation program with Matlab language and simulated track irregularity time-domain samples with based on the frequency domain power spectrum equivalent method. The time-domain samples are input Activate function of dynamic simulation. Built up a vehicle-track system model with the multi-body dynamic simulation software ADAMS / Rail. Under the excitation of Chinese main line track spectrum, American track spectrum and zhengwu track spectrum separatly,Compared the difference between the dynamic responses of vehicle-track system. The thesis can make the numerical simulations of track irregularity time-domain samples based on Matlab simulation program. The built vehicles-track system model can be used to analysis the system dynamic responses. From the above two aspects, completed the compared analysis to Chinese three main lines'track spectrum, zhengwu track spectrum and other typical track spectrums. Essentially achieved the desired target. The thesis can provide a reference to the related field.