• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.328-333
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• 2002

When vehicle travelling along the track which has irregularity such as vertical profile, dynamic forces arise at the Wheel/Rail contact patch by wheel/rail interaction. In particular short wavelength irregularities on dipped joint and small stiffness of connecting rail bring about intense wheel/rail dynamic effects at higher speed. In the paper, a new model for dipped joint rail is developed to study dynamic behavior of track. A cusp behavior on dipped joint was defined by its amplitude and decay factor, which was presented by FRA track classes. The result of case study are presented, which show wheel rail contact force in each track classes, train operation speed and bending flexible rigidity ratio of fishplates which are connecting the rail.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.337.2-337
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• 2002

When vehicle travelling along the track which has irregularity such as vortical profile, dynamic forces arise at the Wheel/Rail contact patch by wheel/rail interaction. In particular short wavelength irregularities on dipped joint and small stiffness of connecting rail bring about intense wheel/rail dynamic effects at higher speed. In the paper, a new model for dipped joint rail is developed to study dynamic behavior of track. (omitted)

• Journal of Welding and Joining
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• 제33권2호
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• pp.23-31
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• 2015

Stainless steel is used in automobile muffler and exhaust systems. However, in comparison with other steels it has a high thermal expansion rate and low thermal conductivity, and undergoes excessive thermal deformation after welding. To address this problem, we evaluated the use of arc brazing in place of welding for the processing of an exhaust system, and investigated the parameters that affect the joint characteristics. Muffler parts STS439 and hot-dipped Al coated steel were used as test specimens, and CuAl brazing wire was used as the filler metal for the cold metal transfer (CMT) welding machine, which is a low heat input arc welder. In addition, a Box-Behnken design of experiment was used, which is a response surface methodology. The main process parameters (current, speed, and torch angle) were used to determine the appropriate welding quality and the mechanical properties of the brazing part was evaluated at the optimal welding condition. The optimal processing condition for arc brazing was 135A current, 51cm/min speed and $74^{\circ}$ torch angle. The process was applied to an actual exhaust system muffler and the prototype was validated by thermal fatigue, thermal shock, and endurance limit tests.

• 터널과지하공간
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• 제10권4호
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• pp.497-505
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• 2000

고속도로 건설을 위한 본 조사지역과 그 주위에는 중생대 백악기의 퇴적암류와 화산암류인 응회암, 치밀 안산암 및 조립 안산암들이 분포하며, 이 암석들을 산성 및 염기성 암맥들이 관입하며 분포하고 있다. 조사지역에서의 주요 불연속 면들은 퇴적암의 충리, 절리 및 단층들로 구성되고 있다. 퇴적암의 층리의 주향은 시점구간에서는 거의 동서방향으로 발달하고 있으나 점차 북동방향으로 휘어졌다가 공구의 중간부이후에서는 거의 남북방향으로 방향이 변하고 있다. 공구내의 절리는 다양한 방향에 걸쳐 발달하며 경사각은 대체로 70도 이상으로 급경사를 이루고 있다. 퇴적암 내에서는 3 내지 4조의 절리군이 발달하나 암맥류가 분포하는 구간에서는 절리의 방향이 훨씬 분산되어 있다. 삼포단층이 공구내의 이리재를 중심으로 북동방향으로 골짜기를 따라 발달하며 구간 STA50k+600에서 STA51k+000구간에는 북서방향의 정단층이 자주 발달하고 있다. 터널굴착시 단층대를 제외한 구간에서는 불연속면들의 방향성에 따른 영향은 없을 것이지만, 층리의 간격이 좁고 많은 절리의 발달로 터널굴착시 터널벽면에서 여굴이 일어날 수 있다.