• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1622-1627
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• 2008

A suspension is a core part, determining running stability and riding quality of vehicles and its stiffness is essential parameters in the process of vehicle designing. Suspension stiffness shall be adjusted to meet requirements of running stability and curve running performance, as adding stiffness to primary suspension for running stability in high-speed running results running performance degradation in curved track. The purpose of the report lies in utilization of usable data for optimization of suspension via analyzing running performance through changing stiffness of railway vehicle suspension.

• 한국군사과학기술학회지
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• 제19권3호
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• pp.395-403
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• 2016

A cylinder-type underwater vehicle for military use that is running near the free surface at the final homing stage to hit a surface ship target is affected by wave force and moment. Since wave can affect an underwater vehicle running at the depth less than half of the modal wave length, it is important to confirm that the underwater vehicle can work well in such a situation. In this paper, wave force and moment per unit wave amplitude depending on wave frequency, wave direction, and vehicle's running depth were calculated by 3-Dimensional panel method, and the numerical results were modeled in external force terms of six degrees of freedom equations of motion. Motion simulation of the underwater vehicle running in various speed, depth, and sea state were performed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.174.1-174
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• 2001

The role of suspension system in tracked vehicles cannot be overestimated because the driving and running conditions of such vehicles are very severe. It reduces the vibration and shock which are generated by road profile in running condition. As the tracked vehicle's running speed increases, more undesired vibrations can be generated by road profile particularly in the situation of field running. Because, the excessive vibration can harm the operation ability of crewmen and stability of complex equipments, the maximum running speed is limited. In this study, to improve the performance of the tracked vehicle system, we examined the feasibility of using the active preview control for the tracked vehicle´s suspension system. First, we developed ...

• 한국안전학회지
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• 제27권1호
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• pp.86-95
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• 2012

The BWIM(Bridge Weigh-In-Motion) is a technology to identify vehicle properties, such as weight, speed, axle spacing and running lane, passing over a bridge by using dynamic response of bridge member. Such information will be used for assessing durability and establishing a maintenance strategy of roadway structures. In this paper, as a first step for developing BWIM system, analytical and experimental studies were conducted in order to verify whether the response of vertical stiffener in steel girder bridge can be used to identify vehicle properties running on the bridge. It was known from this study that such vehicle information could be estimated reasonably by using strain time history curve of a vertical stiffener due to running vehicles. It is because the effect of each axle-load of vehicle appears definitely in the curve. However, as the magnitude of strain of vertical stiffener is effected by running pattern of vehicles, further study is necessary to reduce error when estimating vehicle weight.

• 한국구조물진단유지관리공학회 논문집
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• 제18권1호
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• pp.59-67
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• 2014

경부고속철 PSC 박스 교량의 주행안정성 평가방법을 개발하기 위하여 동적 수치해석을 수행하였다. 교량과 차량의 상호작용력을 고려한 수치 모형을 적용하였다. 3차원 유한요소 뼈대요소를 적용한 교량과 38자유도로 상세하게 모형화된 차량은 공용 중인 KTX의 물성 사양을 적용하였다. 주행속도 500 km/h까지 10 km/h 일정 증가분으로 수치해석하여 차량의 각 방향의 회전각을 교량/일반 도상에서 해석하고 비교하였다. 비교된 회전각비는 기존의 주행안정성 설계기준에 보완될 수 있는 평가방법으로 판단된다.

• 전기학회논문지
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• 제56권11호
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• pp.1955-1961
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• 2007

In this paper, we propose the mathematical model for the vehicle system including running characteristics. The well defined model for a system is necessary to study and to enhance system performance. To model the dynamic properties of vehicle system, we have considered two fundamental parts. The first part is the motion equations for vehicle based on Newton's second law. The second part is the torque dynamics of the traction motor. These parts are affected by outer conditions such as adhesive coefficient, running resistance and gradient resistance. The each parts are presented by the numerical formula. To test the driving characteristics of the developed model, we performed the simulations by dynamic system simulation software, "SIMULINK" and the results are given for several conditions.

• 한국안전학회지
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• 제31권3호
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• pp.130-135
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• 2016

It is very hard to analyze the train derailment safety quantitatively at the curved section because of the diversified affect parameters including the complex interaction between wheel and rail, the train conditions such as the shape of wheel, suspension system, the track conditions such as the radius of curve, cant, transition curve, and the operation conditions, etc. Two major factors related to the running safety of railway vehicle are classified as the railway vehicle and the track condition. In this study, when the railway vehicle passing through curves of actual track condition of subway line NO.3 in seoul ($Yeonsinnae{\leftrightarrow}Gupabal$), the effect that has influence on running safety depending on rail inclination. The analysis result of 1/40 rail inclination condition is more favorable on running safety than other rail inclination conditions because derailment coefficient and wheel unloading ratio are the lowest.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.854-863
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• 2008

A high attention has been paid on the running safety of Korean high-speed train, KTX. In running of KTX on bridge, the running unsafety problem issued from a resonance phenomenon of bridge, which was usually caused by the periodic wheel-loads of train. Therefore, many researches on this running safety of train on bridge have been conducted by domestic or foreign researchers. In this paper, for PSC box-girder bridge which is the representative high-speed railway bridge type, some numerical analyses on the dynamic characteristics of bridge with the non-periodic wheel-loads through vehicle size adjustment were performed. These numerical analyses shows the fact that the resonance phenomenon on bridge was mitigated through vehicle size adjustment. Additional numerical analyses on the vibration reduction of bridge in accordance with the location of size-adjusted vehicle were performed. From these results, it was represented that the adjustment of vehicle size has an effect on the running safety of train as well as the ride comfort.

• 한국정밀공학회지
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• 제28권5호
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• pp.559-564
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• 2011

For the safety of railway, it should be evaluated for the running safety by measuring the derailment coefficient. Although railway has run the fixed and maintained rail, some of railway is derailed. This report shows the results that performed the static load test, main line running test on the basis of the derailment theory and experience. It is executed main line test into more than 90km/h for estimating the curving performance and running safety of depressed center flat car of 3-axle bogie. As the test results, could confirm the curving performance and running safety of depressed center fiat car of 3-axle bogie from the results of the wheel unloading, lateral force, derailment coefficient etc. Derailment coefficient was less than 0.6, and lateral force allowance limit and wheel load reduction ratio were enough safe.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.494-501
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• 1998

This Paper describes the evaluation methods and criteria used to verify running Performance of railway vehicle, and shows results of vehicle dynamics simulation and running performance tests for New Mugunghwa Coaches that were designed and manufactured by DHI in 1997. Through running performance test of New Mugunghwa Coaches, Vibration, Ride Comfort were measured on the condition of service operation. As a results, each simulation and test results meet the criteria proposed by Korean National Railroad(KNR) and Korea Railroad Research Institute(KRRI).