• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3092-3098
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• 2011

This paper deals with analysis of measuring power dissipation when Maglev is running. With the various running scenarios for Maglev, power dissipation was measured and a comparative analysis of it and wheel-on rails were carried out. The purpose of this paper is to confirm the efficiency and economics on operation of Maglev and reflect detail design later. When the running scenarios of Maglev are the status of landing on and levitation, running at rated acceleration and deceleration and according to changes of velocity, the power dissipation was measured. The measured results are analyzed considering with apparent electric power and active power, reactive power and power factor etc. Due to the limited test track condition, it is very limited to compare and analyze Maglev and general trains. Nevertheless, It is a task of great significance to identify the efficiency and economics on operating Maglev through the results of measuring power dissipation. In the future, measuring power dissipation through more various scenarios will be carried out, and the results will be reflected the design.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1282-1288
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• 2006

Upon demands for the requests of rapid, safe and comfort transit, the proven high speed bogie having not only high-quality but also good running performance is required by customer all over the railway vehicle for narrow gauge. Hereupon, the running test on roller testing rig for developed semi-high speed bogie for narrow gauge was carried out in order to verify the running performance and safety. The aim of the test is to assess the dynamic behaviour of the bogie on straight track including the running stability, ride quality, modal frequency and dynamic response.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.72-78
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• 2020

The accident fatality rate has decreased by more than 90% compared to 2006, due to the safety management and safety investment based on the Rail Safety Act. Most railway safety indicators, including fatality rates, have improved significantly from 60% to 80%, reaching the level of developed countries in terms of most railway safety indicators. However, the only staff fatality rate at work is not improved, and it is 3 to 5 times higher than that of developed countries. Most of the fatality occurred during employee's work recently occurred due to accidents hit by train while track work. In principle, when operating track need to check or maintenance, the operation of the train should be stopped and the work carried out. However, in Korea, due to the highest passenger density and train operating density in the world, it is caused by a structural problem that requires workers to enter the track while the train is running and perform various tasks such as maintenance and inspection. In this study, we analyzed the risk of accidents caused by hit by trains on the track, which is the biggest cause of staff fatality, using the main statistics of the last 10 years. In detail, the scenarios of the main causes of hit by trains and workers were formed to suggest the effectiveness of the current preventive measures and supplementary.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1149-1155
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• 2007

The transition area between a bridge and an earthwork is one of the weakest area of track because of the track geometry deterioration caused unequal settlement of backfill of abutment. In case of a ballastless track, the approach slab is installed to prevent the phenomenon. But, if there is occurred the inclined displacement on the approach slab by a settlement of the foundation or formation, the track is also under the inclined displacement. And this defect causes reducing the running stability of a vehicle, the riding comfort of passengers, and the deteriorations of track by excessive impact subjected to the track. In this study, parametric studies were performed to know what is the allowable displacement limit on the approach slab to avoid such a bad effect. The length and amount of unequal settlement of the approach slab was adopted as parameter for numerical analysis. And car body accelerations, variations of wheel force and rail stress and uplift force induced on a fastener clip are investigated. From the result, resonable settlement limits of an approach slab according to slab length was suggested.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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• pp.1711-1718
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• 2004

When the tracked vehicle is running on various types of terrain, the physical properties of the interacting ground can be different. In this paper, the interactions between track link and soft soil ground are investigated using static sinkage theory of soil ground. Grouser surfaces of a track link and triangular patches of ground are implemented for contact detection algorithm. Contact force at each segment area of a track link is computed respectively by using virtual work concept. Bekker's static soil sinkage model is applied for pressure-sinkage relationship and shear stress-shear displacement relationship proposed by Janosi and Hanamoto is used for tangential shear forces. The repetitive normal loads of a terrain are considered because a terrain element is subject to the repetitive loading of the roadwheels of a tracked vehicle. The methods how to apply Bekker's soil theory for multibody track system are proposed in this investigation and demonstrated numerically by high mobility tracked vehicle.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.535-538
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• 1997

Studied in this paper was the lateral displacement of railway vehicle using the multi-body dynamic simulation program (VAMPIRE) and the BASS 501. The lateral displacement of railway vehicle is occurred by thc clearance between wheel flange and rail, the track irregularity, the property of each suspension of vehicle and the cant etc. The results of analysis shown that Vehicle is not interfere with subway platform in any conditions namely the tare and full load condition, the wheel. wear condition and the stationary and running of vehicle.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.863-869
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• 2002

Studied in this paper was the kinematic envelope of the railway vehicle to calculate the lateral displacement using the multi-body dynamic simulation program (VAMPIRE) and the BASS 501. The lateral displacement of railway vehicle is occurred by the clearance between wheel flange and rail, the track irregularity, the property of each suspension of vehicle and the cant of track etc. The results of analysis shown that Vehicle is not interfere with subway platform in any conditions namely the tare and full load condition, the wheel wear condition and the stationary and running of vehicle.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.234-241
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• 2002

In this study, a numerical method which assesses running stability of freight car loading 300m CWR and structural safety of conventional railway track when passing over curves and steel girder bridges is presented. Optimal speed of the freight car is suggest on the basis of numerical reviews for stability of derailment of the freight car and structural safety of track at weak points of the conventional line.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2830-2837
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• 2011

In this paper, a flexible track modeling of turnout was developed and dynamic characteristics of turnout rails were analyzed when a vehicle passed through the turnout. The flexible track modeling is effective to the stiffness and durability design of turnout, because it can capture the deformation and dynamic stress due to the collision of between wheels and rails when the vehicle move to the tongue rail. Also, a more accurate running safety can be obtained by considering the interaction between wheel and rail deformation. Solid finite elements were used for variable cross-sections of rails and the variation of rubber stiffness was modeled. The proposed flexible track modeling in this paper was verified to be valid by comparison with the experiment of the turnout system.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.166-175
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• 2002

Tank track rubbers, which undergo dynamic stresses and strains under various road conditions, leads to a result of considerable internal temperature rise due to the heat generation. Since rubber materials are not fully elastic, a part of the mechanical energy is converted into heat because of the hysteresis loss. Heat generation without adequate heat dissipation leads to heat build-up, i.e. internal temperature rise which, if excessive, exerts a bad influence upon the performance and the life of the tank track rubbers. The purpose of this paper is to predict temperature distributions of the rubber components off tank track subjected to complex dynamic loads under various read conditions. In steady state analysis temperature fields are displayed in contour shapes, and in unsteady analysis the temperature variations of some important nodes are represented graphically with respect to the running time of the tank.