• Proceedings of the KSR Conference
• /
• 1999.05a
• /
• pp.135-142
• /
• 1999

This paper deals with dynamic characteristics of automated guideway transit vehicle with rubber tires. Several models for guideway system of LRT(Light Rail Transit) have been Proposed because of the necessity of guideway system for LRT with rubber tires on exclusive rail unlike steel tires. Here, steering system and bogie system are investigated to compare with dynamic characteristics. On selecting guideway system, the way of vehicle operation should be considered and simultaneously the dynamic characteristics of the vehicle must be evaluated with respect to each guideway. The results show that stability is essential for vehicle with steering system, and that single-axle bogie system gives the good stability, though it is necessary to reduce the guide-wheel force

• Proceedings of the KSR Conference
• /
• 1999.05a
• /
• pp.414-421
• /
• 1999

In this paper, the simplified method for 2-dimensional train/track/bridge interaction analysis is utilized in the analysis of dynamic behavior of bridges in which the eccentricity of axle loads and the effect of the toriosnal forces acting on the bridge are included for the more accurate train/track/bridge interaction analysis. Inverstigations mainly into the influence of vehicle speed on train/track/bridge interactions are carried out for the two cases. The first case is that only train and bridge are considered in the modelling and the other case is that train, track and bridge are considered.

• Proceedings of the KSR Conference
• /
• 1999.05a
• /
• pp.143-150
• /
• 1999

The vibration signals of driving parts of electric train are distorted its signal patterns due to the impact components, which occurs when wheel passes rail joints. An elimination method of the impact components is investigated using adaptive signal processing technique in this study. The result shows that adaptive interference canceling method seems to be more effective than line enhancement technique. The application of adaptive interference canceling method to the signal measured at bogie shows that the extractions of the signals of driving parts of traction motor, reduction gear, and axle bearing are successful. Therefore, only the signals of bogie, which is the place to attach an accelerometer easily, is sufficient for the fault diagnosis and the safety evaluation of electric train. Also, adaptive interference canceling method can be applicable to evaluate the performance of vibration isolation between bogie and car body and to investigate the characteristics of indoor sound.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.1191-1197
• /
• 2009

KTX decelerator is a device to fulfil a role of transmission of turning force to reduction device of an axle by serrate device. Currently, KTX decelerator's TBO(Time Between Overhaul) has 3 years cycle. As for the dissembly maintenance of a device, its maintenance is conducted every 1.4M kms. In this study, since opening of KTX, we analyzed reliability, maintainability, availability of KTX decelerator by researching historical records of maintenance of the decelerator, and based on above data, investigated whether its TBO cycle and maintenance works properly or not And we considered maintenance policies of KTX decelerator to improve efficiency in maintenance in the future.

• Proceedings of the KSR Conference
• /
• 2001.05a
• /
• pp.295-302
• /
• 2001

The lateral stability of curved continuous welded rail (CWR) is studied fur buckling prevention. This study includes the influences of vehicle induced loads on the thermal buckling behavior of straight and curved CWR tracks. quasi-static loads model is assumed to determine the uplift region, which occurs due to the vertical track deformation induced by wheel loads of vehicle. Parametric numerical analyses are performed to calculate the upper and lower critical buckling temperatures of CWR tracks. The parameters include track lateral resistance, track curvature, longitudinal stiffness, tie-ballast friction coefficient, axle load, truck center spacing, and the ratio of lateral to vertical vehicle load. This study provides a guideline for the improvement or stability for dynamic buckling in on tracks.

• Proceedings of the KSR Conference
• /
• 1998.05a
• /
• pp.466-473
• /
• 1998

LRV(Light Rail Vehicle) is one of the most useful way for urban transit. HDPIC has designed and manufactured the LRV train set for Manila Line 1 expansion. The LRV is composed of two carbody sections which are coupled by a articulated bogie. The articulated bogie and two motorized bogies have slewing rings in order to improve the curving performance and ride quality. Carbody structures are mainly made of low-carbon stainless steel (STS301L), and the carbody bolsters and draft sills are made of rolled steel for welded structures. The authority's specifications specified the design load conditions and weight limits. Design load conditions are vertical load, compressive load and diagonal jacking, and the maximum axle load is 10.7 ton. In order to meet those requirements, the stiffness and strength of carbody structure were predicted using finite element analysis during design stage. The half or full structure is modeled and analyzed with design load conditions, and critical areas are analysed in detail using sub-modeling method. The strength and strength of carbody structure was also verified by the load test. The analysis and test results show a good agreement.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.2
• /
• pp.1-7
• /
• 2016

Although the second driving device of KTX, which consists of the wheel and the axle reduction gears unit, is a mechanically integrated structure, its preventive maintenance (PM) requires two separate intervals due to the different technical requirements. In particular, these subsystems perform attaching and detaching work simultaneously according to the maintenance directive. Therefore, to reduce the unnecessary amount of PM and high logistic availability of the train, it is important to optimize PM with regard to reliability-centered maintenance toward a cost-effective solution. In this study, fault tree analysis and reliability of the subsystems, considering the criticality of the components, were performed using the data derived from field data in maintenance. The cost optimization of the PM was derived from a genetic algorithm considering the target reliability and improvement factor. The cost optimization was derived from a maximum of the fitness function of the individual in generation. The optimal TBO of them using the genetic algorithm was 2.85x106 km, which is reduced to approximately 21% compared to the conventional method.

• Journal of the Korean Society for Railway
• /
• v.11 no.2
• /
• pp.145-150
• /
• 2008

The objective of this research is to design the roller rig for the maintenances of high-speed train bogies operated on the tracks. Roller rigs have been studied and researched to develop the faster, safer and more efficient railway system. It is to reduce the time of testing vehicles and to make as wide a range of tests available as possible. Therefore, it is very important issue to check and evaluate the dynamic responses of high-speed train after several years of operation. This paper presents a study on the conceptual design and dynamic model to develop the roller rig for the routine maintenances of high-speed trains bogies with maximum speed of 350km/h. ANSYS was used to analyze the wheel/roller's contact behavior of driving axle and ADAMS was used to verify and analyze the dynamic behaviors of roller rig.

• Journal of the Korean Society for Railway
• /
• v.17 no.1
• /
• pp.28-34
• /
• 2014

In this paper, a concept design of a rail type ultra-high-speed train is proposed and its dynamic characteristics are analyzed. Instead of the existing solid axle, a new type bogie system and independently rotating wheels are applied in the proposed train. In order to analyze the dynamic characteristics, a multibody dynamic model of a vehicle is developed and the basic validity is verified by eigenvalue analysis. Also, it is shown that the critical speed is improved in comparison to that of existing high-speed train model HEMU-430X. Finally, through 7000R curved track driving analysis at a speed of 550 km/h, the lateral force of the wheels and the derailment quotient are estimated and the applicability of the new concept railway vehicle is confirmed.

• Journal of Korean Society of Steel Construction
• /
• v.28 no.3
• /
• pp.163-171
• /
• 2016

For railway bridges, serviceabilities such as passenger comfort and train riding safety are important design requirements as well as the structural safety of the bridge. In this paper, dynamic responses of a steel box girder bridge by actual passing trains were measured and analyzed by probabilistic method. Deflections and accelerations data at center of side span were collected for about a month by various types of actual passenger and freight trains. Effects by axle weights, types of trains were analyzed. 100 and 200 years maximum values were estimated by Gumbel probability paper and compared with corresponding requirements in the current design code. Except for some cases of accelerations, estimated values were well below the criteria and exceedance probabilities were very low. More data for longer term and other types of bridges are needed to perform comprehensive analysis on the serviceability of railway bridges.