Wheel/Rail Contact Geometry of Different Wheel Tread Profile in High-Speed Railway Turnout

2011 ◽  
Vol 255-260 ◽  
pp. 3988-3992 ◽  
Author(s):  
Rong Chen ◽  
Wang Ping ◽  
Yang Song

Train/turnout dynamic interaction is exacerbated by high speed of passenger train and heavy load of freight train, and wheel/rail relation is one of the key factors that determine the running characteristics of the train. Focusing on three types of wheel treads with different profiles (TB tapered tread, LM worn tread, LMA worn tread), longitudinal distribution of the contact geometric parameters along the switch rail and nose rail of 350km/h No.18 turnout are calculated, such as tread equivalent conicity, coefficient of contact angle difference, roll angle factor, gravitational stiffness of wheelset, gravitational angle stiffness of wheelset, etc. Results show that: (1) LMA worn tread produces the smallest irregularity; (2) wheel/rail vertical impact at the frog will become bigger; (3) Top profile of switch rail and nose rail should be designed according to the wheel tread type so as to mitigate the wheel/rail dynamic interaction and increase the safety and stability of a train.

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Chen Wang ◽  
Shihui Luo ◽  
Ziqiang Xu ◽  
Chang Gao ◽  
Weihua Ma

In order to find out the reason for the bogie frame instability alarm in the high-speed railway vehicle, the influence of wheel tread profile of the unstable vehicle was investigated. By means of wheel-rail contact analysis and dynamics simulation, the effect of tread wear on the bogie frame lateral stability was studied. The result indicates that the concave wear of tread is gradually aggravated with the increase of operation mileage; meanwhile the wheel-rail equivalent conicity also increases. For the rail which has not been grinded for a long time, the wear of gauge corner and wide-worn zone is relatively severe; the matching equivalent conicity is 0.31-0.4 between the worn rail and the concave-worn-tread wheel set. The equivalent conicity between the grinded rail and the concave-worn tread is below 0.25; the equivalent conicities are always below 0.1 between the reprofiled wheel set and various rails. The result of the line test indicates that the lateral acceleration of bogie frame corresponding to the worn wheel-rail can reach 8.5m/s2, and the acceleration after the grinding is reduced below 4.5m/s2. By dynamics simulation, it turns out that the unreasonable wheel-rail matching relationship is the major cause of the bogie frame lateral alarm. With the tread-concave wear being aggravated, the equivalent conicity of wheel-rail matching constantly increases, which leads to the bogie frame lateral instability and then the frame instability alarm.


2013 ◽  
Vol 409-410 ◽  
pp. 1496-1501 ◽  
Author(s):  
Jing Mang Xu ◽  
Ping Wang ◽  
Hao Xu

Electric switch machine locks the crossing rail in the working direction and checks the working status of the crossing. With the increase of train speed, the ZD(J)9 electric switch machine cant satisfy the equipment of high speed railway, This paper studied the optimization; in order to study the lock calculation of nose rail after conversion, a dynamic model is established to research the influence of working status of the crossing. It indicates that for the first traction point, the stress and deformation are mainly affected by scant displacement between nose rail and wing rail; for the second traction point, they are affected by the gap between nose rail and spacer; fastener lateral stiffness doesnt influence the stress status, but the lateral fastener stiffness should not be too small.


2011 ◽  
Vol 101-102 ◽  
pp. 702-707 ◽  
Author(s):  
Zhao Dong Huang ◽  
Bo Qian Fan ◽  
Xiao Ping Ouyang ◽  
Ling Ling Xu ◽  
Zhi Gang Wang

The rolling bearing test rig for heavy vehicles often works under heavy load and high speed, thus it requires high performance for the main shaft and mechanical structure. In this paper a design of test rig for high-speed railway rolling bearings is presented, in which a new structure is adopted to reduce the load on the support bearings. The basic idea is to position the load in a way that they can be balanced by each other.


2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Chao Chang ◽  
Liang Ling ◽  
Zhaoling Han ◽  
Kaiyun Wang ◽  
Wanming Zhai

Wheel hollow wear is a common form of wheel-surface damage in high-speed trains, which is of great concern and a potential threat to the service performance and safety of the high-speed railway system. At the same time, rail corridors in high-speed railways are extensively straightened through the addition of bridges. However, only few studies paid attention to the influence of wheel-profile wear on the train-track-bridge dynamic interaction. This paper reports a study of the high-speed train-track-bridge dynamic interactions under new and hollow worn wheel profiles. A nonlinear rigid-flexible coupled model of a Chinese high-speed train travelling on nonballasted tracks supported by a long-span continuous girder bridge is formulated. This modelling is based on the train-track-bridge interaction theory, the wheel-rail nonelliptical multipoint contact theory, and the modified Craig–Bampton modal synthesis method. The effects of wheel-rail nonlinearity caused by the wheel hollow wear are fully considered. The proposed model is applied to predict the vertical and lateral dynamic responses of the high-speed train-track-bridge system under new and worn wheel profiles, in which a high-speed train passing through a long-span continuous girder bridge at a speed of 350 km/h is considered. The numerical results show that the wheel hollow wear changes the geometric parameters of the wheel-rail contact and then deteriorates the train-track-bridge interactions. The worn wheels can increase the vibration response of the high-speed railway bridges.


2011 ◽  
Vol 474-476 ◽  
pp. 1599-1604 ◽  
Author(s):  
Rong Chen ◽  
Wang Ping ◽  
Xian Kui Wei

Railway turnout, an integrated mechatronics equipment of track technology, is one of key equipments that control the running speed of high-speed railway. During the conversion of turnout, the friction, inclusion of foreign matter and deficient displacement of conversion caused by its own structural characteristics may lead to severe wheel/rail impact. In order to study the influence of conversion deviation on safety and comfort of a train during passing the turnout, train/turnout dynamic model was applied. Taking No.18 turnout on a Passenger Dedicated Line (PDL) with 350km/h as a case study, when the train passed it, the influences of its deficient displacement and inclusion of foreign matter on the following dynamic responses were studied, i.e. wheel load distribution, wheel flange force, dynamic stress of rail, wheel unloading rate, derailment coefficient, as well as the lateral displacements of switch rail and nose rail, etc. Result shows that: (1) the deficient displacement and the inclusion of foreign matter will severely influence the normal operation of the turnout, so the safety and comfort during the train passing through turnout may be affected; (2) During the conversion of turnout, its deficient displacement should be controlled properly, and the foreign matter should be removed during routine maintenance, moreover, a reliable detection system should be set.


Author(s):  
Jingmang Xu ◽  
Ping Wang ◽  
Jian Wang ◽  
Boyang An ◽  
Rong Chen

In this study, a numerical procedure is developed to predict the wear of turnout rails, and the effect of track parameters is investigated. The procedure includes simulation of the dynamic interaction between the train and the turnout, the rolling contact analysis, and the wear model. The dynamic interaction is simulated with the validated commercial software Simpack that uses a space-dependent model of a railway turnout. To reproduce the actual operating conditions of a railway turnout, stochastic variations in the input parameters are considered in the simulation of the dynamic interaction. The rolling contact is analyzed with the semi-Hertzian method and improved FASTSIM algorithm, which enable the contact model to deal with situations of multipoint contact and nonelliptic contact. Based on the Archard’s wear law, the wear model requires the calculation of normal/tangential stresses and a relative slide on the contact patches. The numerical procedure is performed for the selected sections of the vehicle, which runs through the railway turnout in the diverging route. By using the numerical procedure, the effect of track parameters (track gage, rail inclination, and friction coefficient) on the wear of turnout rails is analyzed. The results show that the wear of the front wheelset is more serious than the wear of the rear wheelset for a single vehicle. The degree of wear of switch rails is more severe than that of the stock rails and the difference is more obvious for the front wheelset of the switch rails. The wear of switch rails is mainly concentrated on the rail gage corner, while the wear of stock rails is mainly concentrated on the rail crown. For the analysed CN60-1100-1:18 turnout and the high-speed vehicle CRH2 in China, the rail wear rate could be slowed down by increasing the track gage and decreasing the rail inclination. Alternatively, the rail wear rate could be slowed by decreasing the friction coefficient; however, the variation of wear depth is quite small for friction coefficients that are larger than 0.3.


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