• Composites Research
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• 제14권1호
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• pp.15-21
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• 2001

고강성 카본 섬유 복합재료의 높은 비강성을 이용하여 가압 롤러를 설계·제작하였다. 롤러 제작을 위한 최적의 적층 순서는 유한요소해석을 통해 얻어졌으며, 고무코팅층의 형상은 롤러의 축 길이를 따라 필름에 가해지는 균일 압력에 대해 계산되어진 변형에 근거하여 결정하였다. 제작된 가압 롤러의 정적 변형을 해석결과와 실험적으로 비교하였으며, 그것의 동적 독성은 진동 시험을 통하여 측정하였다.

• Tribology and Lubricants
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• 제25권6호
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• pp.427-431
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• 2009

When a bearing roller is in contact with race ways. excessive pressure peaks occur at the ends of the contact region. They are called edge loading. In this study, a method to determinate crowning quantity of the tapered roller bearing which considers tilting. This method is based on contact analysis.

• 대한기계학회논문집
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• 제11권6호
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• pp.913-922
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• 1987

본 연구에서는 Sn-15% Pb 재료에 대하여 실험에 의한 쌍 로울식 연속 주조의 주조특성을 구하고 로울러 열팽창과 열응력에 대한 유한요소해석을 통하여 제품 두께 와 로울러 변형과의 관계를 밝히고자 한다.

• Tribology and Lubricants
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• 제29권1호
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• pp.27-32
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• 2013

This study examined the effects of surface roughness in the mixed lubrication regime of smooth and rough surfaces for roller bearings. The average flow model was adopted for interaction between the flow rheology of the lubricant and the surface roughness. The average Reynolds equation and related flow factor that describes the coupled effects of surface roughness and flow rheology, the viscosity-pressure and density-pressure equations, the elastic deformation equation, and the force balance equation were solved simultaneously. The results showed that the effects of surface roughness on the film thickness and pressure distribution should be considered, especially in elastohydrodynamic lubrication contact problems.

• 국제물리치료학회지
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• 제10권4호
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• pp.1879-1888
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• 2019

Background: The treatment of pain in the iliotibial band friction syndrome has been difficult to determine, according to studies to date. However, recent studies have suggested that flexibility in the subacute stage of pain in the iliotibial band friction syndrome may help reduce pain. Objective: To investigate the immediate effect on pressure pain threshold and flexibility of the tensor fascia latae and iliotibial band by applying static and dynamic myofascial release foam rolling and self-stretching to adults with shortening iliotibial band. Design: Randomized controlled trial Methods: In this study, 50 subjects who were selected in advance as a randomized controlled trial were randomly allocated using a R Studio program. The included subjects were randomly allocated to three intervention groups. The static self-myofascial release 18 people, dynamic self-myofascial release group 16 people separated the self-stretching group 16 people and conducted a homogeneity check in advance. Before the start of the experiment, after of the experiment, 5 minutes after the end of the experiment, the pressure pain threshold and flexibility change for each part were measured. Results: The results of this study showed that the static self-myofascial release showed a significant difference in the pressure pain threshold in the tensor fascia latae and middle, lower part of the iliotibial band, compared with the other intervention groups (p<.05). In change of flexibility, the static self-myofascial release was significantly different than the other intervention groups (p<.05). Conclusion: The result of this study suggest that static self-myofascial release using foam roller may help to improve the pain and flexibility of the iliotibial band and to apply it as a more discerning intervention.

• 한국염색가공학회지
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• 제17권5호
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• pp.53-60
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• 2005

Fusing press m/c is used for heating and pressing the specimens that are fed into between the two moving belts. Therefore the belt movement, belt temperature, and the pressure between belts must be kept constant. Especially, the belts should move in a limited operation range. When the belts run far out of the operation point, the machine has to be stopped, which results in a product defect because the fusing conditions, e.g., temperature and pressure, change during the transient process time period. It is important to avoid the belt stopping by maintaining the belt movement in a limited range. This study reports about the movement of the endless fusing belt in a long-span roller fusing m/c. The belt position changes as the 1st-order system does; if the roller axes are slanting each other with a certain angle, the belt running around the two rolls shows a dynamic behavior with the time that deviates fastly at the beginning from the initial condion and slows down. Then it reaches at a final position. The skewer the axes, the greater the position change. The inital change rate of the belt becomes large as the skewness of the axes between the two rollers increases.

• 대한기계학회논문집A
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• 제40권10호
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• pp.887-894
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• 2016

압축천연가스(CNG) 압력용기는 D.D.I공정을 통해 실린더부를 제작한 후, 스피닝 공정을 통해 돔 부 성형이 이루어진다. 그러나 스피닝 공정의 입구 부 성형에 관한 연구는 미미하며, 현장 작업자들의 경험이나 시행착오에 의해 제작되고 있는 실정이다. 이에 본 연구에서는 이론 임계좌굴하중 및 유한요소해석에서 축 방향 하중의 비교를 통하여 좌굴발생을 예측하였고, 상용 소프트웨어를 이용하여 돔부의 좌굴 방지를 위한 방법을 제안하였다. 또한, 입구 부 성형을 위하여 돔 부와 롤러가 맞닿는 점에서의 돔부의 반경에 따른 롤러 하중을 분석하고, 이를 토대로 입구 부 성형을 수행하였다.

• 한국기계가공학회지
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• 제3권2호
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• pp.86-94
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• 2004

The flash temperature distribution on the contact surfaces between cam and roller-follower mechanism was analysed numerically. The elasto-hydrodynamic lubrication pressure and film thickness were used to get the accurate analysis results. The temperature distribution was obtained by numerical integration by making use of Carslaw and Jaeger's formulation to the whole contact surfaces. The maximum flash temperature was increased with both the increasing slip ratio of the contact surface and increasing external load Profile of the temperature distribution was affected by the sliding velocity of the surface.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.71-76
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• 2008

This paper is concerned with the active vibration control of elevator by means of the active roller guide. To this end, a dynamic model for the horizontal vibration of the elevator consisting of a supporting frame, cage and active roller guides was derived using the energy method. Free vibration analysis was then carried out based on the equations of motion. Active vibration controller was designed based on the equations of motion using the LQR theory and applied to the numerical model. Rail irregularity and wind pressure variation were considered as external disturbance in the numerical simulations. The numerical results show that the active vibration control of elevator is possible.

• 한국정밀공학회지
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• 제24권8호통권197호
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• pp.74-80
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• 2007

The distortion of printed pattern is frequently observed in gravure offset printing process, which can be a serious problem in printing process for printed electronics. The mechanism of pattern distortion is studied and the factors which affect the amount and shape of distortion are found using FEM. The amount and shape of distortion is influenced by material properties of the roller, thickness of roller, applied load, and so on. As the printing pressure increases and Possion ratio increases, the degree of the image distortion increases. And the increase of the thickness of rubber roller brings a large distortion of image, too. In some cases, the distortion of printed pattern can reach a few hundred micromillimeters. The comparison of the experiment result and the simulation result shows good agreement in their quantitative tendency.