• International Journal of Railway
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• 제6권1호
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• pp.13-25
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• 2013

Railpad prevents damage of the tie and ballast by reducing the impact and high frequency vibration, which occurs when a vehicle load transfers to a tie. But elasticity of the railpad can decrease under vehicle load and over usable period. If that happens, railpad will become stiffer. Increase in stiffness of the railpad also translates into a rise in track maintenance cost because it accelerates the damage of the track. In this study, accelerated heat ageing test was performed to predict an expectable lifetime of the railpad. As a result, it was predicted to be about sixteen years at $25^{\circ}C$ that life time of railpad using NR rubber from Arrhenius relationship. Also, it was predicted to be about thirty-two days at $100^{\circ}C$. At this time, a standard rate of thickness change is approximately within 12%.

• 한국음향학회지
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• 제18권1호
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• pp.32-37
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• 1999

철도소음·진동은 철도변에 거주하는 인근 주민들에게 커다란 불만족 인자로 등장하고 있다. 특히, 철도소음은 철도변에 거주하는 주민들에게 정신적, 심리적, 육체적으로 심각한 영향을 미치고 있으며 이로인해 철도변에 거주하는 주민들은 많은 괴로움을 호소하고 있는 실정이며, 특히 본 설문조사 결과 철도변 주민들은 경제적인 보상보다는 쾌적한 주거환경에 더 많은 관심을 가지고 있는 것으로 나타났다. 그럼에도 불구하고 국내의 경우 철도소음에 대한 심각성은 인식하고 있지만 구체적인 자료의 축적 및 연구가 이루어지지 않아 효율적인 대책수립이 매우 어려운 실정이다. 이러한 관점에서 본 연구에서는 철도변 주민들을 대상으로 설문조사를 실시하여 철도소음의 실태 및 영향을 파악해 보았으며, 이를 토대로 향후 효율적인 철도소음의 대책수립 및 철도소음에 대한 세부적인 기준설정을 위한 기초적인 자료를 제시하고자 한다.

• 대한환경공학회지
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• 제22권6호
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• pp.1103-1111
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• 2000

철도는 급격한 산업발전과정에서 주요 교통수단으로 등장하여 국가발전과 국민편의에 지대한 공헌을 해왔다. 그러나 이러한 발전과 편리함에도 불구하고 심각한 소음 진동공해를 유발시켜 철도변 인근주민들의 불만족 지적률이 날로 증가하는 실정이다. 또한 철도진동은 철도소음에 비해 상대적으로 인식정도가 낮아 직접적인 피해를 유발시키지 않을 것으로 생각하고 있으나, 외국의 조사결과에 의하면 철도진동은 철도주변 거주자들의 육체적 정신적 건강에 심각한 영향을 미치고 있는 것으로 나타났다. 따라서 철도진동은 철도소음과 더불어 정온한 주거환경을 해치는 중요한 변수로 등장하고 있으며, 효율적인 철도진동 대책수립을 위해서는 우리 실정에 적합한 자료의 확보가 선행되어야 하지만, 아직까지 국내에서는 이에 대한 인식의 부족과 자료의 결핍 등으로 인해 많온 어려움을 겪고 있다. 이러한 관점에서 본 연구는 전북지역의 주요도 시인 전주, 익산, 군산을 대상으로 설문조사를 실시하여 철도진동의 영향에 따른 피해정도와 주관적 반응을 평가해 봄으로써 향후 효율적인 철도방진 대책을 수립하는데 기초적인 자료를 제시하고자 한다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.561-566
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• 2008

Recently, because of development of the high speed train technology, the vibration loads by train is significantly increased ever than before. This buried gas pipelines are exposed to both repeated impact loads, and, moreover, they have been influencing by vibration loads than pipeline which is not located under vehicle loads. The vibration characteristic of pipeline is examined by dynamic analysis, and variable is only train speed. Since an effect of magnitude of vibration loads is more critical than cover depth, as increasing the train speed, the vibration speed of buried pipelines is also increased. The slope of vibration velocity is changed by attenuation of wave, at train speed, 300 km/h. From the analysis results, the vibration velocity of pipelines is satisfied with the vibration velocity criteria which are established by Korea Gas Corporation. The results present operation condition of pipelines under rail loads has fully sound integrity based on KOGAS specification.

• 한국소음진동공학회논문집
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• 제21권1호
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• pp.74-80
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• 2011

Front-back vibrations of high-speed elevator need to be suppressed as in the case of lateral vibrations. The dynamic model for the front-back vibrations is different from the lateral vibration model since the supporting structure varies. In this study, a dynamic model was derived using the energy method. Based on the free vibration analysis, it was observed that the fundamental frequency for the front-back vibration is slightly lower than the fundamental frequency of the lateral vibration, which means that the active vibration control should be carried out in both directions. The PPF control algorithm was applied to the numerical model under measured rail irregularities. The numerical results show that the active vibration control of elevator front-back vibration is also possible.

• 소음진동
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• 제11권2호
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• pp.354-364
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• 2001

The vibration induced by high speed train running on rail is dealt with as an environmental problem. The train induced vibration is characterized by moving loads at specific frequencies and soil conditions. In fact, it is predicted that the vibration sources are involved the wheel distance, number of cars, speed of operation, drift of rails, structural born vibration, etc. In this paper the characteristics of transferring vibration induced by the high-speed train in operation is discussed. Field measurements was conducted at region from Chungnam Yungj So-jung-myan to Chungbuk Chungwon hyun-do-myun. In the near future. these data will be used as the fundamental data for establishment of the countermeasure for vibrational reduction of high speed train using the results of the field measurements and quantitative prediction of the vibration level

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.110-115
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• 2002

In this paper, the results of an analysis of the dynamic behavior of the eddy current brake(ECB) system are presented. The measured irregularity of the track in Korean high speed line and the track irregularity given by ERRI(high level) were used for simulation. The wheel-rail profile combination were analyzed with different rail gauges. A model of the bogie with an substitute body for the carbody was implemented in the Multi-body-Simulation Program SIMPACK. The ECB frame was modelled both as flexible body and as rigid body. Four different driving conditions were analyzed. In this study dynamic behavior in general were performed to evaluate the design of eddy current brake system and specially the effect of damper was also studied. A comparison of simulations with and without damper shows that the damper have most effect for lower speed. The simulation results will be verified by comparison with measured data from on line test and also used for improving design.

• Wind and Structures
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• 제31권1호
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• pp.43-57
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• 2020

Considering the wind barriers induced aerodynamic characteristic variations of both bridge deck and trains, this paper studies the effects of wind barriers on the safety and stability of trains as they run through an urban rail transit cable-stayed bridge which tends to be more vulnerable to wind due to its relatively low stiffness and lightweight. For the bridge equipped with wind barriers of different characteristics, the aerodynamic coefficients of trains and bridge decks are obtained from wind tunnel test firstly. And then, the space vibration equations of the wind-train-bridge system are established using the experimentally obtained aerodynamic coefficients. Through solving the dynamic equations, one can calculate the dynamic responses both the trains and bridge. The results indicate that setting wind barriers can effectively reduce the dynamic responses of both the trains and bridge, even though more wind forces acting on the bridge are caused by wind barriers. In addition, for urban rail transit cable-stayed bridges located in strong wind environment, the wind barriers are recommended to be set with 20% porosity and 2.5 m height according to the calculation results of cases with wind barriers porosity and height varying in two wide ranges, i.e., 10% - 40% and 2.0 m to 4.0 m, respectively.

• 한국소음진동공학회논문집
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• 제19권1호
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• pp.85-93
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• 2009

There are many curves in Seoul subway system. Therefore, the noise from subway system in curved line gives displeasure to passenger. The subway noise in curved line is affected not only by rail condition but also wheel condition and dynamic characteristics. The railway curving noise can be divided into 2 categories. The first is the noise due to stick-slip between wheel tread and rail head, and the second is one by wheel flange contact on rail side. Because of these phenomena - stick-slip and wheel flange contact - wheels are worn seriously. In this study the curving noise was reviewed by using eigen-mode of wheel and waterfall plot which shows noise level in time-frequency domain. And also those were reviewed in viewpoint of stick-slip noise and wheel flange contact noise. Finally, the relationship between curving noise and wheel wear was studied.

• 한국소음진동공학회논문집
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• 제13권6호
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• pp.474-483
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• 2003

In this study, the dynamic characteristics of a catenary system and pantograph supplying electrical power to high-speed trains are investigated. One of the most important issues accompanied by increasing the speed of high-speed rail is stabilization of current collection. To stabilize current collection, it is necessary the contact force between the catenary and the pantograph to be kept continuous without loss of contact. The analytical model of a catenary and a pantograph is constructed to simulate the behavior of an actual system. The analysis of the catenary based on the Finite Element Method (FEM) is performed to develop a catenary model suitable for high speed operation. The reliability of the models is verified by the comparison of the excitation test with Fast Fourier Transform (FFT) data of the actual system. The static deflection of the catenary, stiffness variation in contact lines, dynamic response of the catenary undergoing constant moving load, contact force, and each state of the pantograph model were calculated. It is confirmed that a catenary and pantograph model are necessary for studying the dynamic behavior of the pantograph system.