• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.245-254
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• 1993

In this study, the influence of eccentricity on bearing capacity of strip footing has been investigated by the model tests using the carbon rods, the upper bound method of limit analysis, and Meyerhof method of the limit equilibrium method. In applying the upper bound, the failure mechanism based on model tests was used. There was good agreement between the result of model tests and the upper bound method of limit analysis, but Meyerhof method yielded low bearing capacity and underestimated the effect of eccentricity on bearing capacity. Besides, the influences of footing width, embedment depth and base friction on the bearing capacity have been examined.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1993.04a
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• pp.97-107
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• 1993

프시톤 형상에 관한 연구는 엔진의 열효율을 상승시키는데 중점을 두었으나 캘리포니아주의 환경 관련 법안을 계기로 공해 물질의 배출을 중이는 방향으로 연구가 이루어지고 있다. 즉, 실린더내의 최고 온도와 압력을 적정한 수준에서 조절하여 공해물질의 방출을 극소화시키면서 열효율을 높힐 수 있는 방안에 대한 연구를 많이 진행하고 있다. 본 논문은 유한요소법을 이용하여 저마찰 패드식 피스톤에 대한 트라이볼로지적 해석으로 피스톤의 편심에 따른 압력 분포도 해석, 마찰력과 피스톤의 동특성에 대하여 알아보고자 한다. 이들을 해석하기 위한 가장 중요한 역학적 상태량은 피스톤 표면의 압력 분포와 피스톤의 편심량이며 특히, 압력 분포 해석은 피스톤의 유막 설계시 기본이 된다.

• The monthly packaging world
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• s.252
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• pp.67-71
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• 2014

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.380.2-380
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• 2002

SRM(Switched Reluctance Motor) 내부의 Radial Force는 소음ㆍ진동의 주원인이 되는 가진력으로 작용하는 것으로 알려져 있다. 따라서 본 논문에서는 Radial Force의 주 요인인 Motor 내부의 Air Gap 편심에 따른 반경방향의 전자기 가진력을 전자장 수치해석을 통하여 해석하고 소음ㆍ진동에 미치는 영향을 분석하였다. Air Gap 편심량을 변화시켜 가면서 Stator, Rotor의 Local Force와 Gloval Force인 Torque Fluctuation을 해석하고 이를 실험 결과와 비교함으로서 해석결과의 타당성을 입증하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.3
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• pp.241-250
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• 2011

The new gerotor developed in this paper has an inner rotor in which a circular arc is inserted between the hypocycloid and epicycloid curves, whereas the outer rotor is designed using the simulation results for the rotor and a modification method. The new gerotor has no cusps and loops and no limit on the eccentricity. We increase the average flow rate by adding a new design parameter, $\gamma$, which is the inclined angle of the inner rotor at the intersection of the hypocycloid and the circular arc. A calculation method to calculate the chamber area is also developed. This method can also be used to calculate the flow rate and flow rate irregularity when the contact points are unknown. The control of eccentricity and $\gamma$ is expected to lead to an efficient rotor.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.2
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• pp.195-201
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• 2012

According to many customers' requests, optical measurement module (OMM) applications using automatic measuring devices to measure the machined part rapidly on a machine tool have increased steeply. Touch trigger probes are being used for job setup and feature inspection as automatic measuring devices, and this makes quality checking and machining compensation possible. Therefore, in this study, the use of touch trigger probes for accurate measurement of the machined part has been studied and a macro program for a hole measuring cycle has been developed. This hole is the most common feature to be measured, but conventional methods are still not free from measuring error. In addition, the eccentricity change of the least square circle was simulated according to the roundness error in a hole measurement. To evaluate the reliability of this study, the developed hole-measuring program was executed to measure the hole plate on the machine and verify the roundness error in the eccentricity simulation result.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.320-324
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• 2016

A new eccentric forging process for camber bolts has been suggested in this study. The camber bolt is manufactured by a two-step process: the typical forging process for normal bolts and the trimming process for the eccentric flange. The processes are performed under high forging load and generate a large amount of chip during trimming. A new forging process has been required in order to overcome these problems. The eccentric forging is the new process in which the load axis is offset from the central axis, as against central load applied in a typical forging process. The eccentric forging process could reduce forging load and save the amount of chip. In order to manufacture camber bolts by an optimum process, it is required to adjust the geometry of eccentric die and the offset from the central axis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.187-196
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• 1992

This paper estimates the bearing capacity of the eccentrically loaded footing by the upper bound of limit analysis method. Meyerhof method and Saran method used the limit equilibrium method in the estimation of bearing capacity. But, in this study the bearing capacity is estimated by the upper bound method. In applying the upper bound, the result depends on the failure mechanism. So this analysis uses the conventional failure mechanisms or the modified failure mechanisms. The comparisions are made between the results from this analysis and those obtained from the limit equilibrium method. Also, the influences of the parameters-eccentricity, internal friction angle, surcharge, G-value, and base friction of the footing on the bearing capacity factors have been examined.

• Korean Journal of Optics and Photonics
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• v.22 no.4
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• pp.161-169
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• 2011

In this paper, a tolerance allocation method using Monte-Carlo simulation with measured reflective eccentricity for high-sensitive IR optics is proposed. During optics fabrication and alignment, reflective eccentricity was measured using an optical centration measurement instrument. A Monte-Carlo simulation was performed using measured eccentricity data, and it gives statistical estimated performance of the optics after fabrication. The validity of the proposed tolerance allocation method was verified comparing the estimated MTF result with the measured MTF result of the fabricated optics.

• Magazine of the Korea Concrete Institute
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• v.5 no.2
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• pp.129-139
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• 1993

본 연구에서는 철근콘크리트 기둥의 거동을 예측하기 위하여 층상화 방법을 이용한 유한요소 해석방법이 제안되었다. 콘크리트의 강도와 철근비가 기둥의 극한강도와 거동에 미치는 영향을 규명하기 위하여 세장비가 10, 60, 100인 정방형 단면(80$\times$80mm)을 갖는 30개의 기둥에 대하여 실험을 수행하였다. 이때, 콘크리트의 강도는 25.5, 63.5, 86.2MPa로, 철근비는 1.98, 3.95%로 변화시켰다. 또한, 단부조건은 양단힌지로 하고, 편심량은 기둥은 양단에서 같은 방향으로 24mm로 동일하게 하였다. 본 연구에서 제안된 해석방법은 철근콘크리트 기둥의 거동을 잘 예측하며, ACI의 모멘트 확대계수법은 고강도 콘크리트 장주에 대해서는 안전측이 아닌 것으로 나타났다. 콘크리트의 강도가 기둥의 극한강도에 미치는 영향은 기둥의 세장비가 증가할수록 감소하였으며, 콘크리트의 강도가 커질수록 세장기둥의 좌굴파괴 가능성은 증가하였다. 또한, 철근비를 증가시킬 경우, 기둥의 축력이 최대가 될 때의 모멘트가 증가되었으며, 기둥의 극한강도 증가량은 단주보다는 장주에서 더 크게 나타났다. 철근비 증가에 의해 나타나는 이러한 기둥의 극한강도 증가량과 모멘트 증가량은 콘크리트의 강도가 커질수록 증대되었다.