• Proceedings of the KSR Conference
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• 2002.10b
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• pp.1094-1099
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• 2002

In this paper, a numerical method for vehicle-track interaction analysis is developed to evaluate vertical dynamic force subjected to rail surface. A vehicle is modelled by lumped masses system and track by multi layered continuous beam system. The equation of motion of vehicle and track interaction system is derived by considering compatibility condition at the contact points between wheel and rail. The input vibration source is given by the empirical formula of power spectral density of track irregularity, which is suggested by FRA. Using this method, dynamic impact factors with the train speed are evaluated.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.580-585
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• 2003

Korean high speed train (KHST) has adopted a combined electric/ mechanic (friction) braking system. Electric brakes are consist of rheostatic brake, regenerative brake and eddy current brake and mechanical brakes are composed of disc brake, wheel disc brake and tread brake. In this paper, we introduce the braking performance test and the measuring method of mechanical brake. And disc brake performance has been reviewed by the experimental method. The on-line test of KHST has been carried out up to 260 km/h and proved that the disc braking capacity of KHST is sufficient.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.652-659
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• 2000

The machine structure or parts has been arrive at a fracture, depend on crack by repeated load. Machine designer is estimate of fatigue strength in early stages the design for prevent fatigue fracture, then necessary its load history. This research study is using diesel locomotive in measurement of load history for fatigue design of rolling stock. The relation between velocity and amplitude of load history was found. We confirmed that the increase of velocity make to increase the magnitude of amplitude.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.765-770
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• 2005

This paper presents a development and evaluation of a spring type tensioning device for Korea railroad. The wheel type tensioning device used in the Korea railroad requires much time and labor for maintenance including wire replacement and oil application. So, we found it necessary to develop a new type of maintenance-free tensioning device. In this paper, we introduced a spring type tensioning device for Korea railroad.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.101-106
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• 2005

During braking at a train, thermal energy is generated due to the frictions between disk and lining and wheel and shoe. In general, the braking transfers the kinetic energy into thermal energy. Therefore. the frictional characteristics are varied according to the braking force, the thermal resistance, and the thermostable, etc. Using a Dynamo testing we have studied the frictional characteristics and the thermal distribution to investigate a stable speed and to improve the testing method through comparing and analysing in the measurement or the thermocouple temperature and infrared camera.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.771-776
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• 2005

This paper presents field test results of a spring type tensioning device for Korea railroad. The wheel type tensioning device used in the Korea railroad requires much time and labor for maintenance including wire replacement and oil application. So, we found it necessary to develop a new type of maintenance-free tensioning device. In this paper, we introduced field test results of spring type tensioning devices for Korea railroad.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1264-1269
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• 2006

Measurement and estimation of rail irregularity is an important factor to concern travelling safety of train. Now a day, rail irregularity have been measured by EM120 and ROGER 1000K imported from MERMAC Co. Italy and making researches actively in Korea. This paper mainly consider to find correlation between acceleration value of wheel axle in HSR350x and rail irregularity value measured by EM120.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.321-328
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• 1998

In this study we have studied running stability, safety and passenger comfort of the Chinese first class passenger car made by our company and CCRW. A fine analysis model of 72 d.o.f. was constructed for simulating dynamic behavior of the car on straight and curved tracks having irregularity configurations. We have calculated the various characteristic values such as critical speed, lateral force, derailment ratio, wheel unloading ratio and passenger comfort index, then evaluated them by comparing with reference values.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.129-136
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• 1998

The LIM can be used as a transport system with wheel structure. The structural tolerance cause the airgap unbalance and that effects on the LIM performance. The effect of airgap unbalance on the motor performance such as thrust force, velocity and armature current are investigated by using Finite Element Analysis (FEA). From this numerical works, it is known that the airgap unbalance almost does not effect on the motor performance and LIM for transport system is robust to the structural tolerance.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.6
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• pp.635-642
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• 2004

In electric motor coaches. the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control based on disturbance observer and sensor-less vector control. The numerical simulation and experimental results point out that the proposed readhesion control system has the desired driving wheel torque response for the tested bogie system of electric coach. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.