• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2236-2241
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• 2008

To predict the dynamic behaviour of railway vehicle, the complex vehicle structure has been described by mathmatical model such as mass, spring and damper. Air-spring has played a major role to improve dynamic characteristics, vibration isolation and ride comfort. The mechanical behaviour of air spring is very complicated. The behaviour is based on fluid and thermodynamic mechanisms. The main parameters of air spring are stiffness due to compression of the air in the spring and surge reservoir, change of area stiffness and orifice damping. In this paper, we have studied an air-spring modeling method and compared the difference between calculation and test.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1779-1792
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• 2009

Now, the goal of the third generation KTX project is to create a new species of high speed train in order to open a new era of high speed railway system in history by authentic Korean technology and innovative design. Now the third generation KTX, must go beyond the original stagnant paradigm and be positioned as an emotional resource which is creating a shift in the public's perspective of transportation and expanding the idea that transportation intersects the two distinct realms of culture and environment as well. In addition, the overall design should reflect the Korean culture and characteristics, simple yet resonant, both the interior space and the exterior fuselage should portray the dynamic heritage of Korea such as the powerful yet subdued energy of Jung Joong Dong. In short, through the symbolic key words in Korean, Dong(Dynamics), Mek(Pulse), Ryu(Flow), Gam(Sensibility), the third generation KTX design project aims to create an new identity of Korean high speed railway which can stand globally.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.645-650
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• 2003

Wheel/Rail geometric constraint relationships, such as effective conicity and gravitational stiffness, strongly influence the lateral dynamics of railway vehicles. In general, these geometric contact characteristics are nonlinear functions of the wheelset lateral displacement. There is a need to develop a wheel/rail contact simulation program for wheels and rails with arbitrary profiles for the prediction of the dynamic behavior of railway vehicles. An algorithm to simulate any combination of wheels and rails is employed and a GUI for easy analysis is constructed. The simulation program is applied to KTX which will run on both KTX and conventional rails, two rail standards having different rail profiles. The results show that the two rail systems have different geometric contact characteristic

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.369-376
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• 2003

The purpose of this work is to general approach to numerically simulating wear in rolling and sliding contact area between wheel and rail interface based on the analysis of dynamics characteristics with general MBS package. A simulation scheme is developed that calculates the wear at a detailed and various level. The estimation of material removal follows Archard's wear equation which states that the reduction of volume is linearly proportional to the sliding distance, the normal applied load and the wear coefficient and inverse proportional to hardness. The main research application is the wheel-rail contact of Korea High Speed Railway.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.3-7
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• 2003

The dynamics of the pantograph motion and contact forces of the high-speed railway are investigated through signals. acquired during a test run. The signals are obtained from accelerometers, load cells, and strain gauges attached to various positions of the pantograph, and they are processed in time-and frequency-domains to evaluate the dynamic characteristics and load forces. The natural frequencies of the pantograph is found to be 8.5Hz. There also are frequency components varying linearly with the train speed. The signal frequency components above 40Hz are attenuated as they pass through the primary and secondary suspensions.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.522-529
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• 2006

Running train is one of the most main factor for railway bridge vibration. The repeated forces with equidistant axles cause the magnification of dynamic responses which relates with maintenance of the track structure and structure-borne noises. The noise problem is one of the most important issues in services of light rail transit system which usually passes through towns. The noise of railway bridges can be divided into the noise from track-vehicle system and structure-borne noises. In the present study, The vibration and noise of the LRT bridge will be investigated with utilizing dynamics responses from moving train as input data for noise analysis.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.295-308
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• 2009

Now, the goal of the third generation KTX project is to create a new species of high speed train in order to open a new era of high speed railway system in history by authentic Korean technology and innovative design. Now the third generation KTX, must go beyond the original stagnant paradigm and be positioned as an emotional resource which is creating a shift in the public's perspective of transportation and expanding the idea that transportation intersects the two distinct realms of culture and environment as well. In addition, the overall design should reflect the Korean culture and characteristics, simple yet resonant, both the interior space and the exterior fuselage should portray the dynamic heritage of Korea such as the powerful yet subdued energy of Jung Joong Dong. In short, through the symbolic in Korean, Dong(Dynamics), Mek(Pulse), Ryu(Flow), Gam(Sensibility), the third generation KTX design project aims to create an new identity of Korean high speed railway which can stand globally.

• Proceedings of the KSR Conference
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• 2006.11a
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• pp.229-238
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• 2006

In general, the Maglev vehicle is run over an elevated guideway consisting of steel or concrete structure. Since the running behavior of the vehicle is affected by the flexibility of the guideway, the consideration of the flexibility of guideway is needed for evaluating the dynamics of both the vehicle and guideway. A new method based on flexible multibody dynamics is proposed to model the Maglew vehicle. This method combines the levitation controller, vehicle, and guideway into a coupled model To verify the method, an urban transit is analyzed using the method and discussions are carried out.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.29-30
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• 2006

The interior noise of KTX in tunnel has become an issue since the commercial operating in April 2004. The analysis of the interior noise of KTX in tunnel with concrete track shows sharply increased noise level in the range of 80Hz that is the natural frequency of the KTX carbody. We know that the booming noise inside KTX in tunnel with concrete track is generated by noise outside gangway and rolling noise at the carbody natural frequency. In this Study noise reduction methods are discussed on the basis of the comparison of the KTX and KHST noise characteristics. Alternatively, the effect of the modified mud-flap on the interior noise is introduced.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1093-1098
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• 2002

Dynamic behaviors of the Korean High-speed Train(KHST) have been analyzed to investigate the performance on the stability, the safety and the ride comfort. Multi-body dynamics analysis program using Recursive method, called RecurDyn, have been employed in the numerical simulation. To model the wheel-rail contact, the RecurDyn uses its built-in module which uses the square root creep law. The accuracy of the rail module in RecurDyn. however, decreases in the analysis of flange contact because it linearizes the shape of the wheel and rail. To solve this problem, a nonlinear contact theory have been developed that considers the profiles of the wheel and rail. The results show that the KHST still needs more stability. The problem should be solved by the examinations of module and modeling.