• Design & Manufacturing
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• 제11권2호
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• pp.25-28
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• 2017

Semiconductor equipment manufacturers desire to enhance efficiency of Sub Fab to increase semiconductor productivity. For this reason, Sub Fab equipment manufacturers are developing Integrated System that combined modules with multiple facilities. Integrated System is required to apply Mount Leveler of Wedge Type in compliance with weight increase compared with existing single equipment and product shape change. This thesis analyzes main design variables of components of Wedge Mount Leveler and carries out structure analysis using ANSYS, finite element analysis program Analysis shows that main design variables of components of Wedge Mount Leveler has self-locking condition by friction force of Wedge and adjusting bolt. Each friction force hinges upon Wedge angle and Friction Coefficient of contact surface and upon the thread angle and Friction Coefficient of contact surface. Also, as a result of carrying out structure analysis of Wedge Mount Leveler, deflection and stress appears in different depending on the height of the level.

• Tribology and Lubricants
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• 제34권2호
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• pp.55-59
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• 2018

This paper proposes a new type of electro-mechanical wedge brake for commercial vehicles. The brake operates on a novel mechanism for self-boosting braking friction forces using eccentric shafts, and involves wedges that are inserted between the rampbridge and traverse; this self-boosting mechanism is explained herein. A dynamic analysis using ADAMS was conducted, and the findings are reported. The constraint and contact conditions are explained to verify the precision of the dynamic analysis. The dynamic analysis shows that in the proposed mechanism, the self-boosting effect occurs as desired. However, it is also noted that the system has a limitation in terms of the production of unlimited braking forces that can jam the roller inside the wedges. After demonstrating the self-boosting effect, dynamic analyses are performed for several values of the wedge angles and friction coefficients between the brake pads and disks. Conventionally, a lower wedge angle has been suggested owing to its provision of a larger clamping force for given friction coefficients. However, it is noted that lower wedge angles can lead to a higher probability of occurrence of undesirable high braking forces, which can jam the roller into the wedge; thus, a larger wedge angle is preferable for avoiding the undesirable jamming phenomena. These analysis results are presented and discussed herein.

• 한국철도학회논문집
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• 제20권3호
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• pp.299-310
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• 2017

본 연구에서는 3-piece 마찰 웨지 화차의 주행성능을 예측하기 위해 ADAMS/View에서 독립하중 마찰 웨지 모델을 개발하였다. 마찰 웨지 모델은 볼스터의 좌우, 수직방향에 따른 마찰을 각각 구현해줄 수 있다. 개발된 마찰 웨지 모델은 ADAMS/Rail 차량 모델에 적용하여 동역학 해석 결과를 얻었다. 대상차량은 임계속도 210km/h를 가진다. 직선 안정성 해석에서 UIC518에 근거해 차체의 횡, 수직방향 한계 가속도에 만족하는 것을 확인하였다. 300R 곡선에서 해석 적용 속도는 70km/h로 UIC518에 근거해 차체, 대차의 한계 가속도에 만족하였다. 또한 "철도차량 안전기준에 관한 규칙"의 윤중감소율, 횡압, 탈선계수에 만족하는 것을 확인하였다.

• 한국산업융합학회 논문집
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• 제2권2호
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• pp.35-39
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• 1999

Results of two-part wedge analysis and centrifuge test executed by Zornberg et al. were compared for geotextile-reinforced slope stability. For two-part wedge analysis results of two cases, a frictional case considering internal friction of soil as interwedge friction and a nonfrictional case not considering, were also compared and evaluated. The analysis was based on limit equilibrium and two-part wedge was divided into slices as many as the number of geotextiles to obtain a maximum tension distribution mobilized in reinforcements. A significant observation was that the distribution was a triangular shape with maximum tension of geotextile at a transit point of interwedge. The number of geotextiles and failure surface of frictional case were reasonable and more comparable to results of the centrifuge tests than those of nonfrictional case. Therefore it can be said that two-part wedge analysis is recommendable for design analysis of reinforced slopes if an interwedge angle is regarded to be an angle of internal friction in soil.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.80-83
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• 2004

The FRP plate or sheet bonding technology was widely used for strengthening deficient RC structures. The strengthened structure using FRP bonding scheme, however, experience the complex interfacial behaviour which is difficult to predict. Therefore, the unbonded scheme using some anchorage device can be is an alternative for more reliable design. In this study, wedge-type anchor for FRP plate is developed for the unbonded flexural strengthening scheme. Some parameter study using 2D finite element method is performed. The analysis parameters are taken as wedge-guide friction coefficients, wedge- FRP ,.friction coefficient and wedge inclination angle. Based on the parameter study, more efficient anchors are designed and tested. The test result show that the developed anchor assure about $80\%$ FRP strength, which is higher performance than typical bonding scheme. Last, 3D finite element analysis is performed.

• Structural Engineering and Mechanics
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• 제15권6호
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• pp.609-628
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• 2003

Mechanical anchorage devices are generally tested in the laboratory and may be analyzed using the finite element method. These devices are composed of many components interacting through diverse contact interfaces. Generally, a Coulomb friction law is sufficient to take into account friction between smooth surfaces. However, in the case of mechanical anchorages, a gripping system, named herein the wedge-tendon system, is used to anchor the prestressing tendon. The wedge inner surface is made of a series of triangular notches designed to grip the tendon. In this particular case, the Coulomb law is not adapted to simulate the contact interface. The present paper deals with a new constitutive contact/gripping law to simulate the gripping effect. A parameter identification procedure, based on experimental results as well as on a finite element/neural network approach, is presented. It is demonstrated that all parameters have been selected in a satisfactory way and that the proposed constitutive law is well adapted to simulate the wedge gripping effect taking place in a mechanical anchorage device.

• 대한토목학회논문집
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• 제9권1호
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• pp.53-62
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• 1989

점변일차원이층류(漸變一次元二層流)모델로서의 염수(塩水)쐐기형상(形狀)의 계산(計算)을 행함에 있어서 필요(必要)한 계면저항계수(界面低抗係數)의 평가수단(評價手段)에 대(對)하여 논(論)한다. 예(例)를 들면, 폭(幅)이 좁은 실험수로(實驗水路)에서 얻어진 염수(塩水)쐐기의 형상(形狀)에 의해 계면저항계수(界面低抗係數)를 역산(逆算)하는 경우는 실제(實際)의 하천(河川)에서는 무시(無視)할 수 있는 수로(水路)의 측벽(側壁)의 영향(影響)을 보정(補正)하지 않으면 안된다. 본연구(本硏究)에서는 이러한 점(點)을 고려(考慮), 정상(定常) 염수(塩水)쐐기의 형상(形狀) 및 계면저항계수(界面低抗係數)에 미치는 수로(水路)의 측벽(側壁)의 영향(影響)을 밝힌다.

• 한국유체기계학회 논문집
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• 제10권5호
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• pp.46-53
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• 2007

Stem friction coefficient and valve factor are very important parameters for the evaluation of valve performance. In this study, the characteristics of stem friction coefficient and valve factor are analyzed, and thor bounding value is determined. The hydraulic testing is performed for many flexible wedge gate valves in the plant and statistical method is applied to the determination of bounding value. According to the results of this study, stem friction coefficient does not change much with differential pressure, and the bounding value of closing stroke is higher than that of opening stroke. The valve factor of valves with high differential pressure is higher than that of valves with medium differential pressure. It means valve factor is more sensitive to the differential pressure than the stem friction coefficient. Valve factor of the closing stroke is higher than that of opening stroke due to piston effect.

• International Journal of Aerospace System Engineering
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• 제7권2호
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• pp.1-5
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• 2020

When a rigid wedge is indented in to a semi-infinite block, the material is bulged up around the wedge that is generally called lip. The previous works in this filed considered the outer profile of the lip to be linear. But, present authors observed both experimentally and with the aid of finite element analysis that the profile of the lip is not always linear, and it depends on the angle of the wedge and friction parameters. So, in this work, attempts have been made to calculate hardness of indentation for different wedge angles and friction parameters. As hardness is intrinsic property of material, consideration of either linear or parabolic lip will not be affected much. A comparative study of hardness for linear and parabolic free surface profiles of the piled up material around the cone is analyzed in this work.

• 한국자동차공학회논문집
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• 제20권1호
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• pp.112-118
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• 2012

The electronic wedge brake is one of the brake-by-wire systems with a self-energizing effect. The electronic wedge brake has faster response than the conventional hydraulic brake and requires only about one-tenth the power to operate. However, the electronic wedge brake cannot be implemented unless the self-energizing effect is reliably controlled. The self-energizing mechanisms may result in unintentional lock up and are very sensitive to environment and parametric variations of the friction coefficient. In this study, the electronic wedge brake is modeled into dynamic equations, and a sliding mode controller is designed based on the model. The performance of the proposed controller is verified in simulations.