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Study On A Theory And Method For Probabilistic Analysis Of High-speed Railway Continuous Welded Rail Track Dynamic Stability

Posted on:2004-11-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:Q Y LiFull Text:PDF
GTID:1102360122470046Subject:Road and Railway Engineering
Abstract/Summary:PDF Full Text Request
High-speed railway is a common trend for world railway, and become an important sign of railway modernization. In order to guarantee high-speed train running safe and stably, the safety reserve must be enough for the stability of high-speed railway over-section continuously welded rail (CWR) track. The analysis and safety evaluation on the dynamic stability are the key technique of high-speed railway over-section CWR. Studying on a theory for dynamic stability of high-speed railway CWR and a method for safety evaluation is of great theory value and realistic meaning. In this paper, probability concepts are applied to establish the probabilistic analysis method on dynamic stability of high-speed railway CWR. Dynamic stability and its reliability of high-speed railway CWR are analyzed on the base of first-passage failure criterion. This paper aims to give out design reliability index and the safe allowable temperature limits under design reliability index for high-speed railway CWR dynamic stability in china.According to Based on Lyapunov's mathematical definition of probabilistic stability, the CWR probabilistic stability criterion is proposed on the basis of the first-passage probabilities of stochastic processes. Using probability theory and mathematical statistics, probabilistic model on randomicity of the dynamic stability analysis system are built. By means of trigonometrical progression method and the mainline track spectrum, the sample function of the Chinese mainline railway track random geometric irregularity is simulated. With the data obtained from track geometry inspection car on Qinhuangdao-Shenyang special line for passenger transport and ARMA time series model, the sample function of high-speed railway track random geometric irregularity are simulated. Based on existing literature, the artificial bogie crawl waves at various different speeds are randomly simulated. A stochastic variable model is presented to simulate ballast lateral stiffness.Combining the vibration theory with the stability theory, vehicle-rail dynamic analysis model and equations of motion vehicle-rail system are put forward. By Monte-Carlo simulation method, a program is developed to analyze random vibration of vehicle-rail coupling system. With the help of the above theoretical models and simulation program, the dynamic responses of CWR due to the possible excitation are obtained. The validities of the calculation results is verified by experiments.Applied the maximum entropy calculation method to fit the distribution of extremes for dynamic response processes, a quasi-static analysis method on dynamic reliability of CWR stability is established. By the calibration method, reliability index of current maintenance standard for mainline railway CWR in china is analyzed. An important conclusion that reliability index for different curved radius is different and reliability index of small radius curve is lower than big radius curve is reached. According to the maximum entropy method, a program applied to compute reliability of CWR dynamic stability is worked out and put into practice to analyze reliability of CWR dynamic stability, getting the safety allowable temperature under design reliability index. Suggestion the design reliability index of high-speed railway CWR dynamic stability to be settled 4.2By quoting a renewal process model and first-passage failure criterion, the analysis method of CWR dynamic stability in design reference period is proposed. The reliability of high-speed railway CWR dynamic stability is analyzed. Its result is compared with quasi-static analysis method and random simulation analysis method. It recommend 60 as the safe allowable temperature limits for high-speed railway CWR track. In the end, fuzziness of CWR stability safety limit is discussed.The study of probabilistic analysis methods for CWR dynamic stability analysis provides scientific basis for the designing, the constructing and managing of CWR, and lays a foundation for probabilistic design of CWR. The research achievements...
Keywords/Search Tags:high-speed railway, continuously welded rail (CWR), dynamic stability, probabilistic analysis, dynamic reliability, safety evaluation, design reliability index, first-passage failure criterion, maximum entropy method, Monte-Carlo simulation method
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