Vehicle-Track-Bridge System Dynamic Analysis Model And Track Irregularities Control On Quasi $ High-speed Railway

The influence on runnin safety and stability of quasi- & high-speed vehicle under trackirregularity excitation is the topic in the thesis. Taking vehicle-track or vehicle-track-bridge verticaland lateral coupling system dynamic model as analytical method, the thesis systematically discussesdynamic behavior of quasi- & high-speed vehicles excited by track irregularities in ballast track, theinfluence on dynamic response of rail/wheel system excited by rail surface vertical short-wavelengthroughness, serviceability of running vehicles on bridge under excitation of special track irregularitiescaused by bridge arch, pier uneven settlement and subsidence error between abutment and subgrade.Track irregularities are actually complicated random processes, consisting of approximatelystationary ergodic processes of general track irregularities in entire length and non-stationaryprocesses reflecting geometric state of the local deflects in track. The thesis describes thecharacteristics of track irregularities in two ways, the characteristics of track local irregularity isexpressed with peak, peak-peak, amplitude variety rate and wavelength, half-wavelength, cycle, etc,stationary and ergodic irregularities described by PSD and amplitude statistic parameters.Considering needs of vehicle-track dynamic model input, track local irregularities are described asmathematical functions, such as cosine sinusoidal, exponent function, random track irregularitysimulate from PSD by use of second filter method.Based on rail/wheel reaction and track/bride reaction theory and systems engineering theory,new vehicle-track and vehicle-track-bridge system dynamic models are established and discussed inare: (1) vehicle-track and vehicle-track-bridge system dynamic models are coupled in vertical andlateral; (2) track vibration on bridge is taken in account, track on bridge is considered as one or twolayer continuous-point supported rail model, according to actual track structure, interaction betweenvehicle and bridge transfer from track structure; (3) three type of ballastless track models (tie-embanked, elastic-tie-block, slab track) are presented; (4) models reflect the main feature of actualvehicle, track and bridge structure, the response computation frequency of models is relatively broad,which can be applied to analyze both low frequency and high frequency vibration.Considering the characteristics of vehicle-track and vehicle-track-bridge differentialequations (time-variation coefficient matrix and moving train load, the thesis divides the wholesystem into three subsystems (vehicle, track and bridge) which are coupled by rail/wheel forces andtrack/bridge forces, proposes a new numerical computation method of system differential equations,which combine Newmark direct integration method with Newton iteration method, and twoparameters(ratio of modified displacement increment norms and displacement increment norms,I'atio of asidenCe forC bo norms and fome inCreIUen norms) are used tO cothel boonW and wt Nce in COmPUtathe PrOCes8.By mean of vehicled and Vebooddge Sywt dynamic moduls, the the8isSySteInacaly discusses pe bo or ~ & high~ veas exot by edWarities in ballast tw and btha a ~ pe conlusfo, edeS the bo ondynW pe otndme SySthe excbo by An ch ed bowi -- inndl weld jointS and slab joints, and the -- Of ~ VeM on bridg Unfor exCforor ~ tracx --es cawt by uridge arCb, Pfor uneven bo anu sutrat- enobo ha ana wi pe the -- bo -- ha ed boWaN rOUN an0 od pe in britw.