Analysis Of Temperature Force And Stability Of High Speed Turnout

High-speed, heavy-load railway track structure is the main direction of the currentrailway development. With the technical advantage of its less maintenance and better smoothline conditions, Continuous Welded Rail has become a major form of track structure of highspeed railway. For the regional seamless line, seamless turnout is a key technology. As a weaklink of the track structure, analysis of the stress state of seamless turnout in the seamless lineand its stability under temperature force, have a great significance to the design, constructionand maintenance of seamless turnout and Continuous Welded Rail.In this thesis, a three-dimensional finite element of a high speed seamless turnout hasbeen established. Using it to analysis the stress and stability of the seamless turnout and themain contents are:1. Using the finite software ANSYS established a NO.18high speed turnout calculationmodel. This model has considered the lateral resistance of the fasteners ballast. And the valueof longitudinal resistance of the fasteners is different between normal rail and seamlessturnout. Using this model which is more similar with the real turnout situation, the value offorce and displacement of each rail line in NO.18high speed turnout with three differentswitch heel are calculated. Then get the distribution of the force and displacement and thefunction relationship between the maximum value of force and temperature.2. Based to the unequal wavelength theory of Continuous Welded Rail stability,established the unequal wavelength theory of seamless turnout stability. Calculated thetemperature force under the given track lateral displacement, which happened in the differentcombination of initial wavelengths and bending wavelengths. Then get the ruler of thetemperature force which make the track move lateral. And calculate the permitted temperaturerise amplitude by the function relationship got in forepart. According to the calculation andanalysis, these conclusions are got:(1) The minimum valve of temperature force which make the seamless turnout rail movelateral, always appear in the combination of which bending wavelengths less or equal to theinitial wavelengths. So, when analyzing the seamless turnout stability, the situation thatbending wavelengths longer than initial wavelengths should not be considered. Such aconclusion can be got.(2) To the NO.18high speed seamless turnout, the range of wavelengths which couldmake the turnout rail move lateral most probably is between8meters to10meters. And thesewaves should be paid more attention in the turnout maintenance.(3) The lateral displacement on turnout rail is accumulated by small displacement.According to the calculation and analysis, with a good ballast condition, a temperature circulation could not make the lateral displacement on seamless turnout rail more than thelimited value.3. Established a state equation by the unequal wavelength theory formula and the fittedfunction between temperature and maximum force in turnout rail. Then use Monte-Carlomethod of structure reliability analysis theory calculate the failure probability and reliabilityindex of NO.18high speed turnout with three switch heel structure.