Dynamic Performance of Vehicle-Turnout-Bridge Coupling System in High-Speed Railway

2011 ◽  
Vol 50-51 ◽  
pp. 654-658
Author(s):  
Rong Chen ◽  
Wang Ping ◽  
Shun Xi Quan

In order to study dynamic behavior of vehicle-turnout-bridge coupling system, a vehicle-turnout-bridge dynamic analysis model is established by employing the dynamic finite element method (FEM). When No.18 crossover turnouts(with a speed of 350km/h) are laid symmetrically on the 6×32m continuous beam, influences of turnout/bridge relative position and wheel/rail contact relation in turnout zone on the system dynamic responses are analyzed. The result shows that: wheel/rail contact of turnout zone (especially the frog) has great effect on dynamic responses of turnout on bridge, thus the nose rail height of frog should be optimized to mitigate the wheel load transition and its longitudinal gradient. In terms of the 32m-span continuous beam, the best relative position is frog part of turnout arranged in the range of 1/8 and 1/4 of span.

Author(s):  
R. Chen ◽  
P. Wang ◽  
X. P. Chen

Taking the case of 18# turnout (350km/h) laid on 6×32m continuous girder, a dynamic model for coupling system of vehicle and jointless turnout on bridge was established to analyze the factors that affected dynamic performance of jointless turnout on bridge, and several aspects were taken into consideration, i.e. train’s running quality, rail stress of turnout, vibration of turnout and bridge, and deformation, etc. It is shown that influenced by vibration and deformation of bridge, the train, turnout and bridge form a coupling vibration system, whose dynamic responses are stronger than those caused by train/turnout interaction on subgrade. Wheel/rail contact of turnout zone (especially the frog) has great effect on dynamic responses of jointless turnout on bridge, thus the nose rail height of frog should be optimized to mitigate the wheel load transition and its longitudinal gradient. When a train is passing a jointless turnout on bridge, a reasonable vertical stiffness for bridge is the key to keep its safety and comfort; as for the 32m continuous girder, the ratio of deflection to span should be ≤1/9000 under the ZK load (Chinese standard).


2012 ◽  
Vol 430-432 ◽  
pp. 799-802
Author(s):  
Yang Yang ◽  
Jian Min Ren ◽  
De Zhi Liu

Taking into consideration of the boundary conditions in fluid-solid interactions, the author built the FSI large rectangle aqueduct model of dynamic analysis according to the equation dynamic performance of the fluid-solid coupling system. Large aqueduct of the dynamic properties were analyzed with asymmetric eigenvalue method, dynamic properties rules were calculated by changing the depth of the water in the aqueduct. Aqueduct, also called elevated canal, is usually built over valley, lower land or river for conducting water from a distance or even for shipping.The aqueduct is one of the most important hydraulic structures in Yindaruqin Irrigation Project. After aqueduct is built, all kinds of reasons get its degree of safety descent so as to affect its ordinary running with the time going. Based on fluid-solid coupling system, a FSI analysis model of the aqueduct structure is established.


2011 ◽  
Vol 250-253 ◽  
pp. 3822-3826 ◽  
Author(s):  
Xian Mai Chen ◽  
Xia Xin Tao ◽  
Gao Hang Cui ◽  
Fu Tong Wang

The general track spectrum of Chinese main railway lines (ChinaRLS) and the track spectrum of American railway lines (AmericaRLS) are compared in terms of character of frequency domain, statistical property of time domain samples and dynamic performance. That the wavelength range of the ChinaRLS, which is characterized by the three levels according to the class of railway line, is less than AmericaRLS at common wave band of 1~50m is calculated. Simultaneously, the mean square values of two kinds of track spectra are provided at the detrimental wave bands of 5~10m, 10~20m, and so on. The time-histories of ChinaRLS and AmericaRLS are simulated according to the trigonometric method, and the digital statistical nature of simulated time samples is analyzed. With inputting the two kinds of time-histories into the vehicle-railway system, the comparative analysis of the two kinds of dynamic performances for ChinaRLS and AmericaRLS is done in terms of car body acceleration, rate of wheel load reduction, wheel/rail force, and the dynamic responses of track structure. The result shows that ChinaRLS can characterize the feature of the Chinese track irregularity better than AmericaRLS, the track irregularity with the ChinaRLS of 200km/h is superior to the AmericaRLS, and the track irregularity with the ChinaRLS of 160km/h corresponds to with the sixth of AmericaRLS.


2011 ◽  
Vol 280 ◽  
pp. 186-190
Author(s):  
Shou Tan Song ◽  
Ji Wen Zhang ◽  
Xin Yuan

The dynamic performance of continuous girder under the train in a series of speed is studied through examples, and the main conclusions are given in the following. The resonance mechanism of continuous girder is similar to simply supported beam. The vehicle wheel load forms regular moving load series, which induces periodical action and resonance of the bridge. The damping ratio of bridge itself has less effect on the amplitude at the loading stage, but significant effects appear when the load departs from the bridge. The count of continuous spans also has less impact on the dynamic coefficients, so three continuous spans can be adopted for calculation and analysis. Span and fundamental frequency have significant influence on dynamic coefficients of bridge structures. To extend the span of the bridge structure can reduce the dynamic coefficient while keeping its frequency invariant. The fundamental frequencies of different bridges are corresponding to certain resonant speeds, which calls for the attention in the design.


Author(s):  
Zhonghui Yin ◽  
Jiye Zhang ◽  
Haiying Lu ◽  
Weihua Zhang

Due to urbanisation and the economic challenges of traffic, it is urgently necessary to develop an environmentally friendly virtual-track train with suitable speed, high load capacity and low construction cost in China. To guide the design and evaluate this train’s dynamic behaviour, a spatial-dynamics model has been developed based on the dynamics theory and tyre-road interaction. The proposed dynamics model comprises mechanical vehicle systems, traction and braking characteristics and tyre-road dynamic interactions. The coupling effects amongst those systems of virtual track train are derived theoretically for the first time. The nonlinear characteristics of the tyre are modelled by the transit tyre-magic formula with consideration of road irregularities. Based on a designed PID controller and the comprehensive dynamics model, the dynamic performance of the system can be revealed considering motion coupling effects and complicated excitations, especially under traction and braking conditions. The dynamic responses of whole virtual track train can be obtained by numerical integration under different conditions. The vibration characteristics of such train are assessed under running at a constant speed and during the traction/braking process. The results show that the vibrations of the vehicle system are significantly influenced by road irregularities, especially at high speed ranges. The motions and vibrations of different components are intensive coupled, which should not to be neglected in the dynamics assessment of the virtual track train. Besides, the dynamics model can also be applied to dynamics-related assessment (fatigue, strength and some damage conditions, et al.) and parameter optimisation of the virtual-track train.


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.


2012 ◽  
Vol 500 ◽  
pp. 186-191
Author(s):  
Fu Chun Tao ◽  
Guang Chao Chen ◽  
Bin Jiang ◽  
Bo Chen ◽  
Yan Ding

Based on the field research, we found that in the course of high-speed face milling aluminum, Cutters components prone to deformation as the role of load such as Centrifugal force, Cutting force and Preload. The deformation will directly affect the the dynamic performance of the cutter. So its necessary to reveal the dynamic response of the deformation cutter. We base on the Dynamic model and the modal analysis model, Obtained the deformation cutters dynamic simulation which the cutters deformation is come from the ANSYS. At last we got the method of identifying cutters deflection deformation by vibration signal. With the method we can effectively identifying milling distortion In the cutting process.


2013 ◽  
Vol 13 (03) ◽  
pp. 1250064 ◽  
Author(s):  
CHAOYI XIA ◽  
HE XIA ◽  
NAN ZHANG ◽  
WEIWEI GUO

A dynamic analysis model is established for a coupled high-speed train and bridge system subjected to collision loads. A 5 × 32 m continuous high-speed railway bridge with PC box girders is considered in the illustrative case study. Entire histories of a CRH2 high-speed EMU train running on the bridge are simulated when the truck collision load acts on the bridge pier, from which the dynamic responses such as displacements and accelerations of the bridge, and the running safety indices such as derailment factors, offload factors and lateral wheel/rail forces of the train are computed. For the case study, the running safety indices of the train at different speeds on the bridge when its pier is subjected to a truck collision with different intensities are compared with the corresponding allowances of the Chinese Codes. The results show that the dynamic response of the bridge subjected to truck collision loads is much greater than the one without collision, which can drastically influence the running safety of high-speed trains.


Author(s):  
P. Wang ◽  
R. Chen ◽  
X. P. Chen

Although ballastless track has such advantages as less maintenance and high stability, its big rigidity results in a strong wheel/rail dynamic interaction. In order to study a reasonable stiffness and uneven settlement limit for ballastless track and to optimize the dynamic performance of ballastless track under condition of high-speed running, vehicle together with ballastless track was viewed as an entire coupling system in this study. By adopting numerical simulation, we studied how the stiffness of foundation under rail and uneven settlement of subgrade influence the wheel/rail dynamic interaction. The results show that the reasonable stiffness of foundation under rail is within a range of 20∼30kN/mm, accordingly with a rail deformation within 1.3 ∼ 1.7mm. Through its dynamic analysis under different wavelengths and amplitudes, the uneven settlement of subgrade should be ≤L/1000.


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