A Study on the Evaluation Methods of Running Safety for Railway Vehicle

2006 ◽  
Vol 321-323 ◽  
pp. 1499-1502 ◽  
Author(s):  
Young Sam Ham ◽  
Jai Sung Hong ◽  
Taek Yul Oh
Keyword(s):  
Lateral Force ◽  
Interaction Force ◽  
Load Test ◽  
Railway Vehicle ◽  
Static Load Test ◽  
Track Maintenance ◽  
Running Safety ◽  
Derailment Coefficient ◽  
Main Track ◽  
Measurement And Evaluation

The important factor to evaluate the running safety of a railway vehicle would be the interaction force between wheel and rail(derailment coefficient), for which is one of important factors to check the running safety of a railway vehicle that may cause a tragic accident. Especially, a newly developed vehicle that first runs commercially requires necessarily the measurement and evaluation of derailment coefficient for securing the safety of a vehicle while measuring the derailment coefficient in view of securing running safety could be the more important factor than any other factors. In the meanwhile, it should be also measured the interaction force between wheel and rail in view of track maintenance as well as running safety because increased weight of a vehicle while it is running over a railway may cause damages or destruction on track components such as rails, sleepers and etc consisted of track and any rapid distortion of track. For the reason, the study was intended to evaluate the curving performance and the running safety from the analyses of dynamic running properties, manufacturing wheel axes to measure the working operation of wheels/rail, static load test, derailment coefficient calculated by running test on main track, ratio of wheel unloading, lateral force tolerance of the vehicle that is newly manufactured and commercially running on Gwangju Urban Railway and describe the results.

scholarly journals Optimization on the Crosswind Stability of Trains Using Neural Network Surrogate Model

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Le Zhang ◽  
Tian Li ◽  
Jiye Zhang ◽  
Ronghuan Piao
Keyword(s):  
Contact Force ◽  
Surrogate Model ◽  
Lateral Force ◽  
Dynamics Simulation ◽  
Load Reduction ◽  
Dynamic Parameters ◽  
Wheel Load ◽  
Running Safety ◽  
Derailment Coefficient ◽  
Safety Metrics

AbstractUnder the influence of crosswinds, the running safety of trains will decrease sharply, so it is necessary to optimize the suspension parameters of trains. This paper studies the dynamic performance of high-speed trains under crosswind conditions, and optimizes the running safety of train. A computational fluid dynamics simulation was used to determine the aerodynamic loads and moments experienced by a train. A series of dynamic models of a train, with different dynamic parameters were constructed, and analyzed, with safety metrics for these being determined. Finally, a surrogate model was built and an optimization algorithm was used upon this surrogate model, to find the minimum possible values for: derailment coefficient, vertical wheel-rail contact force, wheel load reduction ratio, wheel lateral force and overturning coefficient. There were 9 design variables, all associated with the dynamic parameters of the bogie. When the train was running with the speed of 350 km/h, under a crosswind speed of 15 m/s, the benchmark dynamic model performed poorly. The derailment coefficient was 1.31. The vertical wheel-rail contact force was 133.30 kN. The wheel load reduction rate was 0.643. The wheel lateral force was 85.67 kN, and the overturning coefficient was 0.425. After optimization, under the same running conditions, the metrics of the train were 0.268, 100.44 kN, 0.474, 34.36 kN, and 0.421, respectively. This paper show that by combining train aerodynamics, vehicle system dynamics and many-objective optimization theory, a train’s stability can be more comprehensively analyzed, with more safety metrics being considered.

Prediction of the Probability of Rail Vehicle Derailment During Grade Crossing Collisions

1982 ◽  
Vol 104 (2) ◽  
pp. 119-132 ◽  
Author(s):  
D. B. Cherchas ◽  
G. W. English ◽  
N. Ritchie ◽  
E. R. McIlveen ◽  
C. Schwier
Keyword(s):  
Computer Simulation ◽  
Preliminary Investigation ◽  
Lateral Force ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Wheel Load ◽  
Road Vehicle ◽  
Rail Vehicle ◽  
Derailment Coefficient ◽  
Grade Crossing

A mathematical model and digital computer simulation are developed to analyze the dynamics of railway and road vehicles during grade crossing collisions. The main objective of the simulation is to relate the probability of derailment to railway vehicle speed; however, a variety of other response characteristics such as railway and road vehicle structure deformation and road vehicle dynamic response can be examined. The criterion for derailment is based on the derailment coefficient, i.e., ratio of wheel flange/railhead lateral force to vertical wheel load. More specifically, the computer simulation utilizes a relationship between the probability of wheel climb commencing and the derailment coefficient, established by Japan National Railways based on their experimental test program. A preliminary investigation is made of the sensitivity of the derailment probability to various collision situations, with the emphasis on increasing rail vehicle speed. Conclusions and recommendations based on this analysis are presented.

scholarly journals Running safety of a railway vehicle in the presence of random track irregularities

Rail Vehicles ◽  
2012 ◽  
pp. 1-10
Author(s):  
Ewa Kardas-Cinal
Keyword(s):  
Vehicle Suspension ◽  
Railway Vehicle ◽  
Technical Standards ◽  
Running Safety ◽  
Derailment Coefficient ◽  
Power Spectral ◽  
Track System ◽  
Track Condition ◽  
Random Character ◽  
Random Track Irregularities

The paper presents the author�s investigations on dynamics of a railway vehicle, especially the effect of various factors on the running safety. The applied simulation methods used for analysis of running safety are in agreement the technical standards UIC 518 and EN 14363. The numerical simulations are performed for non-linear model of railway vehicle (a passenger car) moving along a tangent track with lateral and vertical geometrical irregularities of random character. The obtained results are used to study how the derailment coefficient is affected by the ride velocity, the parameters of the primary and secondary vehicle suspension, the wear of wheel and rail profiles as well as the track condition. The investigation of running safety is further enhanced by performing the spectral analysis of the dynamical responses of the railway vehicle-track system. It is found that there is a direct relation between the obtained power spectral density (PSD) of the derailment coefficient and the PSD of the lateral and angular wheelset displacements showing the characteristic oscillations due to the wheelset hunting. Finally, the paper presents the results of the statistical analysis of local track geometrical irregularities occurring in the vicinity of the track points where the derailment coefficient attains large values.

scholarly journals Analysis on Steering Performance of Active Steering Bogie According to Steering Angle Control in Curve Section

2020 ◽  
Author(s):  
Hyunmoo Hur ◽  
Yujeong Shin ◽  
Dahoon Ahn
Keyword(s):  
Position Control ◽  
Control Method ◽  
Lateral Force ◽  
Future Research ◽  
Railway Vehicle ◽  
Radius Of Curvature ◽  
Steering Angle ◽  
Active Steering ◽  
Derailment Coefficient ◽  
Curved Section

The steering performance according to the steering angle control was tested by using the active steering bogie developed to reduce excessive wheels and rail wear and noise generated when the railway vehicle run in a curved section. As a result of the test of increasing the steering angle in accordance with the target steering angle in the 300m radius of curvature, the bogie is gradually aligned in the radial steering position, and when the control is carried out to 100% of the target steering angle, the bogie angles of the front and rear bogies appeared almost the same. As the steering angle increased, wheel lateral force and derailment coefficient also decreased. Therefore, the validity of the radial steering position control method applied in this paper was confirmed experimentally. This test results will be used for future research on active steering bogie commercialization.

Assessment of derailment risk in railway turnouts through quasi-static analysis and dynamic simulation

2021 ◽  
pp. 095440972110240
Author(s):  
Ping Wang ◽  
Jun Lai ◽  
Tao Liao ◽  
Jingmang Xu ◽  
Jian Wang ◽  
...  
Keyword(s):  
Static Analysis ◽  
Dynamic Simulation ◽  
Economic Losses ◽  
Derailment Coefficient ◽  
Straight Line ◽  
Main Track ◽  
Pass Through ◽  
Multi Body ◽  
Yaw Angle ◽  
Curve Radius

Train derailments in railway switches are becoming more and more common, which have caused serious casualties and economic losses. Most previous studies ignored the derailment mechanism when vehicles pass through the turnout. With this consideration, this work aims to research the 3D derailment coefficient limit and passing performance in turnouts through the quasi-static analysis and multi-body dynamic simulation. The proposed derailment criteria have considered the influence of creep force and wheelset yaw angle. Results show that there are two derailing stages in switch panel, which are climbing the switch rail and stock rail, respectively. The 3D derailment coefficient limit at the region of top width 5 mm to 20 mm is much lower than the main track rail, which shows that wheels are more likely to derail in this area. The curve radius before the switch rail is suggested to be set as 350 m. When the curve radius before turnout is 65 m, the length of the straight line between the curve and turnout needs to be larger than 3 m. This work can provide a good understanding of the derailment limit and give guidance to set safety criteria when vehicles pass through the turnout.

Influence of the railway vehicle properties in the running safety against crosswinds

2021 ◽  
Vol 217 ◽  
pp. 104732
Author(s):  
R. Heleno ◽  
P.A. Montenegro ◽  
H. Carvalho ◽  
D. Ribeiro ◽  
R. Calcada ◽  
...  
Keyword(s):  
Railway Vehicle ◽  
Running Safety
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