• International Journal of Railway
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• v.2 no.4
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• pp.139-146
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• 2009

Vehicle braking in non-electrified rail systems wastes energy. Advanced flywheel technology presents a way to capture and reuse this braking energy to improve vehicle efficiency and so reduce the operating costs and environmental impact of diesel trains. This paper highlights the suitability of flywheels for rail vehicle applications, and proposes a novel mechanical transmission system to apply regenerative braking using a flywheel energy storage device. A computational model is used to illustrate the operation and potential benefits of the energy storage system.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.8
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• pp.7-12
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• 2010

When a vehicle is running, wheel is generating vertical and lateral force on the rail, in addition to load of vehicle, through a complicated set of motions. The derailment coefficient refers to the ratio of lateral force to vertical force(wheel load), and if the value exceeds a certain level, a wheel climbs or jumps over the rail. That's why the value is used as a criterion for running safety. Derailment coefficient of rolling stocks alters according to shape of rail track. I measured three-dimensional angular velocity and acceleration to use 3D Motion Tracker. Test result, derailment coefficient of rolling stocks and shape of rail track examined closely that have fixed relation. Specially, was proved that roll motion has the close coupling relation.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.6
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• pp.119-126
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• 2000

In this paper. a simple high-speed crash test rig for members of vehicle was developed for the improvement of crashworthiness of vehicle's side rail. The cart hanging the specimen is accelerated up to 35 mph by the force of freely dropping weight and 1:3 accelerating pulleys. The cart with shock absorbers travels on the rail roads, so it does not transfer any additional vibration to the specimen. To measure the test results, two types of accelerator are considered. the one is a strain gage type and the other is a piezo type. The test rig is rated good to test the specimen like a side rail of vehicle as developing the vehicle's structures in the early design stage.

• Journal of the Korean Society for Railway
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• v.4 no.4
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• pp.123-130
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• 2001

A chevron rubber spring is used in primary suspension system for rail vehicle. The chevron spring support the load carried and reduces vibration and noise in operation of rail vehicle. The computer simulation using the nonlinear finite element analysis program MARC executed to predict and evaluate the load capacity and stiffness for the chevron spring. The appropriate shape and the material properties are proposed to adjust the required characteristics of chevron spring in the three modes of flexibility. Also, several samples of chevron spring are manufactured and experimented. It is shown that the predicted values agree well the results obtained from experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1533-1536
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• 2003

Dynamic model of the rubber-tired AGT light rail vehicle. various load and boundary conditions between vehicle and infrastructures(running track. guidance rail) were defined to analyze vehicular dynamic behaviors occurred by inclement weather(strong wind and earthquake). The dynamic analysis were performed by using a commercialized software RecurDyn. whose results for the magnitudes of wind and earthquake showed the resultant forces and accelerations between car body and bogie, or bogie guidance frame and infrastructures in the various track conditions(straight or curved tracks) and train velocities. Based on these results, speed limitation of tile vehicle were proposed to ensure system stability and passengers safety.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.119-124
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• 2005

Decision of operation performance mode to minimize the energy consumption of urban rail vehicle. This paper analyses how much acceleration and deceleration of urban rail vehicle should be applied andhow to choose an operation mode to minimize energy consumption when train runs between station within the fixed operation time. The decided operation pattern satisfying the minimum energy consumption becomes a target trajectory and a basis for the controller design criteria. To make this goal it grasps the characteristics of urban rail vehicle, realize operation energy model of urban rail vehicle and verify the accuracy of embodied model the Matlab simulation with the same operation result of real route. It searches for operation pattern to minimize operation energy by changing the acceleration and deceleration on the imaginative route and proposes operation pattern minimizing energy consumption by applying real operation data between Dolgogee-Sukgye section of Seoul Metropolitan Subway Line 6.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.365-368
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• 2005

The dynamic model was developed to analyze vibration acceleration and ride comfort during the operation of rubber-tired light rail vehicles. The ride comfort for standing passengers was analyzed in accordance with ISO 2631-1, UIC 513R, and CEN Draft prENV 12299 using this model. The result was applied to the detail design of Korean-standard, rubber-tired light rail vehicles, and the detail specifications related to ride comfort was determined based on this result. The ride comfort test was performed along the test track by using 2 car-train, and its result was compared with that of the ride comfort analysis, verifying the validity of the developed dynamic model. It was also verified whether or not the developed Korean-standardized, rubber-tired light rail vehicle met specified target specifications on ride comfort.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.18-24
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• 2010

Conventional methods for railway vehicle dynamic analysis have mostly relied on the approximate method based on 2-dimensional contact analysis. Recently, 3-dimensional approaches to achieve an accurate solution for wheel-rail contact analysis have been proposed, but are not practical to apply to actual simulation due to time-consuming processes. The main focus of this study is to present a new method of railway vehicle dynamic analysis by calculating wheel-rail contact forces based on efficient 3-dimensional wheel-rail contact analysis. A 3-dimensional wheel-rail contact analysis and numerical analysis of wheelset dynamic equations will be presented.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.963-969
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• 2010

The railway vehicle consists of wires, bodies, bogies and wheelsets, and each part has very complex mechanism. In this paper, wheel-rail contact algorithm is implemented using C++ and inserted into the ODYN which is a dynamic analysis program. To analyze wheel-rail contact mechanism, information such as contact points, contact angle and rolling radius is calculated according to the wheel and rail profile. Using this information, a table for the calculation of the wheel-rail contact analysis is made according to the lateral displacement. And, the creepage and normal force are calculated and a creep force is estimated by the FASTSIM. To verify the reliability of the wheel-rail contact algorithm, results of the program are compared with the ADAMS/Rail and paper. Finally, a wheelset of the railway vehicle is modeled using ODYN and simulated static and dynamic analysis. And, to verify the reliability of the simulation results, a displacement, velocity, acceleration and force are compared with results of ADAMS/Rail.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.225-230
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• 2009

From the view point of railway vehicle dynamics, the interaction between wheel and rail have an huge effect on the behavior of the vehicle. This phenomenon is an unique motion, only for railway vehicles. Furthermore, close investigation of the backgrounds of the interaction is the key to estimate the dynamic behavior of the vehicle, successfully. To evaluate the model including flexible bodies such as car body and catenary system of the next generation express train, it is necessary to develop proper dynamic solver including a wheel rail contact module. In this study, wheel-rail contact module is developed using the general purpose dynamic solver. First of all, the procedure for calculation of the wheel-rail contact force has been established. Generally, yaw angle of the wheelset is ignored. Sets of information are summarized as tables and splined for further uses. With this information, normal force and creep coefficient can be extracted and used for FASTSIM algorithm, which has been shown good reliability over years. Normal force and longitudinal, lateral force at the contact surface are also calculated. Those data are verified by commercial railway simulation program 'VAMPIRE'. This procedure and program can offer a basic process for estimation of the dynamic behavior and wear of the wheel-rail system, even while running on the curved rail. Finally, multi-dimensional inspection tool will be developed including the prediction of the derailment.