Study On Dynamic Analysis And Control Methods Of The Geometric Irregularity In High-Speed Turnout

Geometric status control for high-speed turnout is the key to ensure the high regularity of the turnout during its maintenance phase. This paper, based on those former works worldwide, systematically studies the control techniques for geometric irregularity of the turnout and its influence on the security and the comfort of travelling, mainly focusing on these subjects:1. Influence of geometric irregularity on the contact relationship in the turnout zoneThe cubic spline interpolation is used to fit the profile of crucial sections in the turnout zone, and this is also applied on the other non-crucial sections. Furthermore, according to the basic theories of the wheel-rail geometric relationships, a subprogram for the turnout wheel-rail contact is designed. This program calculates the influences of geometric irregular factors on wheel-rail contact relations, such as yaw angle of the wheel-set, lateral profile irregularities, track gauges, and track horizontality. The calculating results reveal that:even if the geometric irregularities does not exist, the wheel-rail relationship still varies, and the lateral profile irregularities and track horizontality will enlarge the structural irregularity of the turnout, which can be ameliorated by suitable gauge widening.2. Establish a vehicle-turnout coupled vibration modelIn this model, the subsystem of the vehicle consists of one vehicle, two bogies, and four wheel-sets, totally seven rigid bodies, a primary suspension and a secondary suspension, therefore31degrees of freedom are considered:a vehicle or a bogie has5degrees of freedom:side-roll, pitch, yaw, horizontal and vertical movement, and a wheel-set has4degrees:side-roll, yaw. horizontal and vertical movement. During the formation of the equation of vehicle subsystem, the’"set-in-right-position" rules in the Hamilton principle is improved, to accord with the numeration rules in the finite element method. The sub-model of the turnout contains various parts of real turnout, considering the non-uniform section features of point rails and frog rails, the spacer block, the jacking block, the connecting rod and external locking devices, and also considers non-linear bearings of the sliding bed to the point rails and frog rails. Dynamic calculations of the geometric wheel-rail contact are realized, giving out the structural irregularity of the switch, which is added to the geometric irregularity to form the excitation of the system.3. Characteristics of the vehicle-turnout coupled vibrations and the influences of the geometric irregularityAdopting the program developed during this research, this article analyzes the dynamic characteristics of the vehicle and turnout while the train travels through the turnout straightly or by the sideline, and discusses the influences of the geometric irregularity on traffic security and comfort. The results show that while passing straightly. the vertical vibrations are more vigorous than the transverse vibrations and the lateral vibrations in the point rails and the vertical vibrations in the frog rails are more intense than the other positions, therefore the control of the lateral profile irregularities in the point rails and the vertical profile irregularities in the frog rails should be more noticed. While passing by the sideline, the lateral vibrations are more intense than the vertical vibrations, and are mainly caused by the lack of super elevation of outer rail on the sideline guide curve and the lack of transition curve on the circular curve. The influences of the structural irregularities on the vibrations of the switch are relatively small. And therefore, the standards of control on the geometric irregularity of the turnout in the sideline should be based not on those common standards for straight line and normal rail lines, but on the security and comfort of travelling.4. Control method for the track geometric irregularityA method for calculating the track irregularity spectrum are proposed and validated on different railways, using different methods of irregularity control. From the aspect of the track irregularity spectrum, this article studies the track irregularity control methods, and discusses the pros and cons of these methods. Finally some standard values are proposed by combining the characteristics of vehicle-turnout vibrations, these values are recommended specially for the static control of geometric status on the high-speed railway ballastless track, either in the turnout zone or in the interval sections on rail lines.5. Design of a software for precise adjustments of ballasteless turnout geometry statusA new method for calculating control index of lateral and vertical profile irregularities is firsty proposed by adopting the absolute deviations of the altitudes and horizontal coordinates, and a comparison with the accurate calculating results in the three-dimensional coordinate has proved the correctness of this new method. This method can simply present the relationships among the actual measured values, simulated values and the adjust values. And based on systematic analysis on geometric status, the software’"Adjustment of Ballasteless Turnout Geometry Status" is developed. This software, fixed in the geometric status measure apparatus which is produced by Jiangxi Riyueming Railway Equipment Development Co., Ltd., has been applied in actually adjusting of ballastless railway turnout. Field application results show that this software is user-friendly, well operable, fast response and the proposed adjustment values are rational, proving it to be valuable for more applications and popularizes.