• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.547-557
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• 2020

In this study, damping control devices were applied to the suspension system of a capsule train, and the effects were investigated to improve the ride comfort. The superconductor electrodynamic suspension (SC-EDS) method is used for the capsule train levitation. This method has advantages such as no gap control and a large gap. However, the SC-EDS method has disadvantages such as large gap variation and small damping characteristics against outer vibration, which causes degradation of the ride comfort. In this study, the damping control devices in the primary and secondary suspension were considered to improve the ride comfort in the capsule train. Damping control devices in the primary and secondary suspension can reduce the vibration transmission from outer disturbances to the bogie and from the bogie to the car body, respectively. Simulations for dynamic characteristics analyses were conducted based on the capsule train dynamic model to investigate the effects of the damping control devices on the ride comfort. As a result, it was confirmed that the ride comfort requirements according to the ISO standard can be satisfied by applying the damping control in the capsule train suspension.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1110-1115
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• 2002

The purpose of this study is to analyze the effects of the parameters of the suspension system in railway rolling-stock for KT-23 type passenger vehicle. According to the results of simulation and the small scale vehicle test. Optimal condition was obtained for the stiffness ratio of the primary spring and secondary spring of the suspension system. When the stiffness ratio was Increased, the vortical vibration was increased on the car body for empty and weight car. The result of this study are stable to use of the optimum parameter of the ride duality of KT-23 type vehicle. Also, it is usefull to development of full scale vehicle dynamomer

• Journal of the Korean Society for Precision Engineering
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• v.31 no.9
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• pp.765-771
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• 2014

During the acceptance test of KTX, unexpectedly great lateral vibration in 14th~16th train at 150km/h~200km/h was appeared on a straight line in the winter season. Generally, stiffness of secondary suspension in KTX vehicle is one of the most sensitive components on air temperature. So, we examined that the secondary suspension to be mounted heating system was able to reduce the lateral vibration in the tail car of KTX. Also, we verified that lateral vibration from test results on KTX train with wheel conicity 1/20 disappeared. In this paper, we analysis effective reduction methods and the cause of the lateral vibration using model of KTX train and compare with the test results. The analysis results agree well with test ones. From mode analysis result, lateral vibration is occurred at natural frequency range 0.5~0.6Hz with a negative damping value and its natural frequency disappear gradually according to increasing of wheel concinicy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.617-623
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• 2020

Urban railroad vehicles carry many passengers and are the core of an urban railroad transportation system. Therefore, the dynamic performance of the vehicle must be ensured. Dynamic behaviors such as the vibration and ride comfort of railway vehicles are affected by the structure of the suspension system. We analyzed the dynamic behavior of a railway vehicle according to the suspension system of an urban railway vehicle, which is mainly operated in Korea. For two types of vehicles with different suspension structures, the vibration of the vehicles on railway tracks was measured, and dynamic behavior characteristics such as vibration, ride, and vibration reduction rate were analyzed. The result of the test shows that the vibration performance of the body is superior to that of B-bogie in the lateral direction and that of A-bogie in the vertical direction. Overall, the ride quality of the A-bogie car is superior to that of B-bogie. When analyzing the vibration attenuation rate of primary suspension system, the vibration attenuation performance of B-bogie with coil spring was superior to that of A-bogie with a conical rubber spring. The secondary suspension system has better vibration attenuation performance for A-bogie with air springs compared to coil springs.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.543-550
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• 2011

The development of railway vehicles such as new mechanism of railway vehicle or design parameters of suspension have been used the application of scaled roller rig to the study of railway vehicle dynamics. In this paper, the critical speed was compared between full scale and 1:5 scale of numerical model. And to verify the simulation results, the critical speed was confirmed using the 1:5 scaled roller rig. According to the results, we expect that the developed roller rig will be used in the study for the dynamic characteristics of railway vehicle.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.835-840
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• 2008

Next Generation High Speed Train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project is in stage of concept design and so, it needs to take some review and analysis the characteristics of suspensions on the view of concept design. A vehicle modeling is made of modified Korean High Speed Train bogie model with Vampire program and analyzed the effect on the dynamic performances according to the variation of primary and secondary suspension characteristics. The results would be useful to manage the potential risks in the next stage of basic and precision design that will be done by the manufacturing company.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.572-579
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• 1998

In this paper, an analytical model for analyzing the interaction between train and floating slab track is presented. Train is modelled by 4-lumped masses system which are composed of a carbody supported by secondary suspension, a bogie frame supported by primary suspension, and two wheelsets supported by nonlinear Hertzian springs. In the track model, rail is considered to have a distributed mass and to be supported discretely at sleepers above ballast on slab. The slab supported by discrete isolators put on fixed floor is modelled by finite beam elements. Numerical analyses are carried out to examine anti-vibration effect of the GERB slab track which is same type laid in Puchon station on the subway No. 7 Line.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.387-392
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• 2008

Next Generation High Speed Train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project is in stage of concept design and so, it needs to take some review and analysis the characteristics of suspensions on the view of concept design. A train dynamic modeling is modified with the one car model presented in the previous conference and it was extended to 6cars models having the same suspensions and added some connection's characteristics between the cars with Vampire program. It is used to analyze the effect on the dynamic performances according to the variation of primary and secondary suspension characteristics in the condition of 6 cars configuration. The results would be useful to manage the potential risks in the next stage of basic and critical design that will be done by the manufacturing company.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.49-51
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• 1998

The 4-pole LHSM was composed of the figure-of-eight shaped 3-phase armature windings. DC field windings, and the segmented secondary with the transverse bar track. These parameters were computed from the analytical expressions and examined from FEM analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.84-90
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• 2018

In constructing the multi-body dynamics model to analyze the behavior of the railway vehicle, it is very important to understand the properties of the suspension elements that constitute the suspension system. Among them, coil springs, which are mainly used in primary and secondary suspension systems, clearly show the axial stiffness in the drawings, but the lateral properties of the coil springs are not specified clearly, making it difficult to construct a dynamic analysis model. Therefore, in this paper, the model for analyzing the lateral stiffness of the coil spring is examined. A finite element method was applied to analyze the lateral stiffness of the coil spring and numerical analysis was performed by applying the coil spring lateral stiffness analysis model proposed by Krettek and Sobczak. And the test to analyze the lateral stiffness of coil spring was conducted. As a result of comparing with the test results, it was found that the results obtained by applying the lateral stiffness analysis model of Krettek and Sobczak and correcting the correction coefficient are similar to those of the test results.