• International Journal of Railway
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• v.3 no.3
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• pp.95-105
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• 2010

In this paper, a procedure is proposed to optimize bogie suspension parameters in view of minimizing wheel wear produced by curve negotiation, though meeting stability requirements. The problem is dealt with in the form of a constrained minimization problem, in which wheel wear evaluated over a given service scenario is introduced as the cost function to be minimized, and the requirements on vehicle stability are formulated in terms of constraints. The procedure is applied to the case of a non-powered passenger car for high-speed service, and the results obtained are discussed. It is shown that long wheelbase bogie may provide better overall performances than bogies having comparatively short wheelbase. Furthermore, a sensitivity analysis is performed, to define the effect on the optimization results of improving the performances of the yaw dampers in the bogie and of using a different wheel profile.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.862-863
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• 2011

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.241-242
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• 2012

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.183-188
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• 2009

The High speed electrical multiple 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 comes in stage of basic design and so, it needs to take some review and analysis the characteristics of suspensions on the view of basic design. The vehicle model for dynamic analysis is made from the concept design model that used for the preliminary design review with Vampire program and it is modeled with three linear secondary dampers and two shear springs separated from the bush elements in previous model. The optimization technique is applied to search the proper range of linear characteristics for the suspension elements to satisfy the stability performance at speed 130m/s (about 460km/h). The results shows there are some optimum points according to the variation of primary and secondary suspension characteristics and it would be useful to make a decision to select the proper suspension elements in the precision design that will be done by the manufacturing company.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.8
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• pp.773-778
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• 2009

Chevron rubber springs are used in primary suspensions for rail vehicle. Chevron rubber spring have function which reduce vibration and noise, support load carried in operation of rail vehicle. Prediction and evaluation of characteristics are very important in design procedure to assure the safety and reliability of the rubber spring. The computer simulation using the nonlinear finite element analysis program executed to predict and evaluate the load capacity and stiffness for the chevron spring. The non-linear properties of rubber which are described as strain energy functions are important parameters. These are determined by material tests which are uniaxial tension, equi-biaxial tension and shear test. The appropriate shape and material properties are proposed to adjust the required characteristics of rubber springs in the three modes of flexibility.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.186-192
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• 2001

A chevron rubber spring is used in primary suspension system for rail vehicle. The chevron spring has function which support the load carried and reduce vibration and noise in operation of rail vehicle. The computer simulation using the non-linear finite element analysis program MARC executed to predict and evaluate the load capacity and stiffness for tile chevron spring. The appropriate shape and 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 tile results obtained from experiments.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1435-1440
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• 2008

High-speed train under development is a type of EMU(electric multiple units). Since power sources like motors and gears are distributed in the high-speed EMU, the high-speed EMU generates vibration and sound more than the articulated high-speed train. Vibration of vehicle, vibration between rails and wheels, hunting of bogie and snake motion reduce ride comfort. In this paper, to decrease the vibration of the articulated high-speed train, improvements were presented using an analytical model and a simulation model. The simulation model of the high-speed EMU was designed on the basis of the korean high-speed train and the design parameters for ride comfort were showed and the dynamic characteristics of the vehicle was understood. To consider the characteristics of the vehicle suspension, the analytical model was designed and the simulation model was verified with it.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.111-119
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• 2017

In this study, deflection limits based on the vibration serviceability of guideway structures are proposed considering maglev train-guideway interaction. Equations of motion are derived for a simplified maglev railway. Feedback constants for the control of the electromagnetic force for levitation are optimized in order to minimize the airgap fluctuations. Deflection limits for a guideway are calculated for various operating speeds of a maglev train, span lengths of a guideway, and natural frequencies and damping ratios of the second suspension in order to satisfy the serviceability criteria for airgaps and for the vertical acceleration of a cabin. From the analysis results, proposed are requirements for the second suspension of maglev trains and deflection limits for guideway structures.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.484-490
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• 2000

The freight wagon with weld fabricated 1-piece bogies, which was developed to increase operating speed, reveals its difficulties in maintenance. The weld-fabricated bogies were composed of two-stage coil spring and dry friction damping mechanism. The inborn wear parts and rather complicated structure mattes bogie maintenance difficult. In order to relieve this difficulties, the application of maintenance free rubber suspension is proposed by bogie maunfacturer, Taeyang Precision Limited. This study was conducted to determine design parameters of proposed rubber suspension by means of vehicle dynamic simulation and parametric study. The target critical speed of bogie was set over 150km/h for the preparation of further speed-up of freight wagon.

• 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.