• Proceedings of the KSR Conference
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• 2001.10a
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• pp.187-191
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• 2001

Diesel locomotive engine is the main source of train noise in these days but hard to reduce the level by barrier for it emitted from high location. For the passing high level noise properties of diesel locomotive engine, there are needs of changing the environmental railway limit to maximum level from equivalent. In this study we investigate the noise characteristics of the diesel electric locomotive according to the change of notch. From the result we found out the frequency of engine cycle noise and the shape of noise spectrum.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1047-1053
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• 2009

This paper examined an applicability of optimum algorithm to develope an electric railway pole foundation automated design system. Based on the optimization theory that considered subgrade and bearing capacity characteristics, decided an optimum section of electric railway pole foundation. In this research, Optimum algorithm used the feasible direction method in structural analysis and design efficiently. Design variables are considered geometric properties and anchor bolt area of the electric railway pole foundation as optimum construction cost. Constraints are considered settlement., overturning and activity of foundation. And, also composed flexural and shearing strength. According to optimum analysis result., optimization theory is available more economical design comparing with railway pole foundation that is constructed by current standard drawing, and applicability verified in automated design system development.

• International Journal of Railway
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• v.7 no.2
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• pp.57-63
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• 2014

This paper presents the optimization of suspension characteristics under the condition of curved track railway vehicles. Reducing lateral acceleration on curved track is an issue for high-speed railway vehicles. In terms of curved track running environments, reducing the lateral vibration of railway vehicles is critical to safety and curving performance. The properties of lateral damping and stiffness of both primary and secondary suspension show effect on wheel-set, bogie and car-body. Analysis for reducing the lateral vibration of rail vehicles with respect to the characteristics of both primary and secondary suspension has been developed using ADAMS/Rail. Response Surface Method has been chosen for the purpose of verifying correlation effects among design parameters. Also, this paper suggests the method for designing optimal suspension of railway vehicles on curved track. The optimization result indicates decrement of lateral acceleration on wheel-set by 3% and bogie by 1% on curved track. Finally, this paper comes to the conclusion that suspension system of railway vehicle (KTX I) is properly designed when regarding lateral vibration of railway vehicle on diverse curved track condition.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.715-720
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• 2002

The dynamic load effects, generated by moving trains, are transferred to the railway bridges through tracks. The dynamic load effects may vary due to the dynamic characteristics of the applied vehicle loads and the railway bridges including the track system. However, the track models have been neglected or simplified by spring elements in the most studies since it is quite complicated to consider the track systems in the dynamic analysis models of railway bridges. In this study track system on railway bridges are modeled using a three-dimensional discrete-support model that can simulate the load carrying behavior of tracks. A 40m simply supported prestressed concrete box-girder system adopted for high-speed railway bridges are modeled for simulation works. The train models are composed of 20 cars for KTX. The dynamic response of railway bridges are found to be affected depending on whether the track model is considered for not. The influencing rate depends on the traveling speed and different wheel-axle distance. The dynamic bridge response decreases remarkably by the track systems around the resonant frequency. Therefore, the resonance effect can be reduced by modifying the track properties in the railway bridge, especially for KTX trains.

• Journal of the Korean Society for Railway
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• v.11 no.2
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• pp.158-164
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• 2008

Abstract Infiltration of rainfall that may lead to reduce resistance force due to reduction of matric suction and to increase driving force due to increase of self weight makes the slope fail. There are many specifications to make slope stable based on factor of safety. Although result of slope stability analysis satisfy the specifications, slope failures triggered by rainfall are frequently occurred in reality because slope stability analysis cannot consider uncertainty of each soil properties. This is why conventional analysis has limitation and development of alternative method is needed. So it is suggested to adopt the reliability analysis rather than design based on factor of safety into designing safer structure. Through the evaluation of handicaps for the factor of safety based design, calculation of soil properties by site investigation, and reliability analysis considering distribution of each soil properties, distribution of failure probability in railway slope is obtained. Then, Risk assessment of slopes in Korean railway is executed from the results. Damage loss and incoming loss are considered as the loss. Using these results, it is possible to make proper countermeasure or efficient maintenance.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.124-131
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• 1999

The axle spring is used in primary suspension component of railway vehicles. The most important factor of axle spring is to have adequate spring constant for comfortable feeling of ride. The non-linear properties of rubber which were important parameter to evaluate of rubber components, were determined by the characteristic test. The finite element analysis of the axle spring are executed to predict the behavior of deformation and stiffness by using commercial FEA code.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.171-176
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• 2002

There are many railway structures which were designed without conidering aseismic capacity. In special, masonry structures constructed long time ago should be reviewed about their resistance to earthquake. In this paper, technique to evaluate the capacity of masonry railway bridge is tried to develop by means of FEM analysis. In general FEM analysis program, 3-D solid element is used for masonry structures and response spectrum analysis procedure is tried. In addition, 3-D solid element has material properties equivalent to mortar-brick composite body. Used FEM program is ABAQUS-CAE.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1578-1583
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• 2007

The suspension system of railway rolling-stock is composed of the primary and secondary suspension elements. Recently, a conical rubber spring is widely used as the primary suspension element due to the merits of the three directional stiffness characteristics. So, understanding the properties and characteristics of the conical rubber spring is very important from the viewpoint of vehicle stability and efficient maintenance. Thus, this study is started to acquire the basic data for maintaining spring elements efficiently. For this, we tested the conical rubber spring samples including a new and old specimen with aging. As a test result, we have obtained the property characteristics of the aged spring comparing with the new product and we describe the results.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.742-747
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• 2005

Electric railroad transformer of a supply of Operation power of DC electric cars is intense fluctuation of load and flows the only big short-circuit current as a accident of the power system. it is a peculiarity more severe than general power transformer. Consequently, researches the properties about the rectifier mold transformer of DC substation and applies with data of safety of the electric railroad transformer. This paper analyzed a failure mode, the accident occurrence scenario and the be latent dangerous unit against the rectifier mold transformer of DC railway system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.3
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• pp.138-142
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• 2015

Most of the existing studies on functional safety testing for the railway signaling system software have focused on verifying the functional safety through the monitoring of internal memory embedded railway signaling system. However, the railway signaling system is one of the typical embedded control system in the railway sector, and the embedded software has a characteristic of generating an appropriate outputs through the combination of internal processing in consideration of the current internal status and external input. Therefore, the test approach of using the interface communication channel can be effective way for the functional testing for railway signaling system software in consideration of these characteristic. Since a communication interface specification of the railway signal system has a the properties of the sequence input and output signals, test-case for software testing is the most effective methodology by MSC (Message Sequence Chart) language, one of the graphic language. The MSC-based test-case generating methodology for signaling system software was proposed in this paper.