• 반도체디스플레이기술학회지
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• 제16권4호
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• pp.25-29
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• 2017

In this paper, we have studied the deformation problem of the scaffold caused by the FDM type 3D printer. The Practical TRIZ technique was used to solve the deformation problem of the scaffold generated from the adhesion surface between the scaffold and the bed. The Practical TRIZ methodology was used to derive the solution and the experiment was conducted on the derived solution. As a result of evaluating the experimental results obtained for the solution, it was found that the deformation of the scaffold was much improved to the satisfactory level.

• 물과 미래
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• 제17권3호
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• pp.197-209
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• 1984

본 연구는 해안제방의 설치에 따른 제방전면의 변형과 제각부의 국소적 지형변동량을 알고자 해운대의 해양조사와 2차원 수리모형실험을 행한 것이며 제방의 설치위치, 해빈경사와 파랑의 특성에 따른 제방제각부의 최대선굴심, 1차경향범위, 최대변동량, 최대변량량까지의 거리 및 2차영향범위의 값들을 구명하여 이들 지형변동량을 줄일 수 있는 해운대해수욕장의 침식대책공법에 이바지 하고자 한다.

• 한국수자원학회논문집
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• 제32권6호
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• pp.697-709
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• 1999

금강에 위치한 부여취수장 부근에서의 유사이송을 모의하기 위해서 2차원 유한요소모형(RMA)이 적용되었다. 다양한 유량조건하에서 하상변동에 관한 모의수행결과는 과거 이 지역에서의 실측된 값과 잘 일치하였다. 본 연구에서 하도부의 개선과 취수구 부근의 하상저하를 위한 대안으로서 수제공 설치와 밤섬제거가 고려되었다. 수제공의 설치에 다라 좌안쪽으로 주흐름이 변환되었으며, 전 영역에 걸쳐서 비슷한 폭을 가진 하도가 형성되었다. 12,030{{{{ { m}^{3 } }}}}/sec 유량조건을 적용하였을 때, 주수로부의 하상고는 약 5∼20{{{{ { cm}_{ } }}}} 저하하였으며, 밤섬제거에 대한 효과는 유사이송에 그다지 큰 영향을 미치지 못하였다. 취수구 상류부에서의 지속적인 하상저하를 위해서 수제공의 설치는 유사유입을 저감시키는데 효과적인 것으로 판단되었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.3214-3219
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• 2011

HONAM High Speed Railway project is under construction with the target to have 350km/h design speed from Songjeong Gwangju City to Osong. The track for the whole section of the line is scheduled to be a concrete track in order to decrease total life cycle cost (LCC) according to the decrease of track destruction. However, the study on the related parts to increase the train speed up to 400km/h is on going in order to strength the competitiveness of high speed railway. On this study, the stress of track has been analyzed according to the concrete track design method of Eisenmann using equivalent depth theory proposed by Odemark for behavior analysis of concrete track on track bed, which is having embankment deformation characteristics by train load. The behavior analysis of track is performed to analyze the stress of track bed layer and track according to the variation of design load and train speed. And also, the characteristics of concrete track have been figured out by analyzing the parameter according to the thickness of track bed layer.

• Elastomers and Composites
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• 제52권3호
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• pp.216-223
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• 2017

The additive manufacturing technology, also called 3D printing, is growing fast. There are several methods for 3D printing. Fused deposition modeling (FDM) type 3D printing is the most popular method because it is simple and inexpensive. Moreover, it can be used for printing various thermoplastic materials. However, it contains the cooling of layered road and causes thermal shrinkage. Thermal shrinkage should be controlled to obtain high-quality products. In this study, temperature distribution and cooling behavior of a layered road with cooling are studied through computer simulation. The thermal shrinkage of the layered road was simulated using the calculated temperature distribution with time. Shape variation of the layered road was predicted as cooling proceeded. Stress between the bed and the layered road was also predicted.This stress was considered as the detaching stress of the layered road from the bed. The simulations were performed for various thermal conductivities and temperatures of the layered road, bed temperature, and chamber temperature of a 3D printer. The simulation results provide detailed information about the layered road for FDM type 3D printing under operational conditions.

• Structural Engineering and Mechanics
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• 제11권5호
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• pp.565-574
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• 2001

Experimental investigation into the behaviour of half-scale brick masonry panels were conducted under cyclic loading normal to the bed joint and parallel to the bed joint. For each cycle, full reloading was performed with the cycle peaks coinciding approximately with the envelope curve. Unloading, however, was carried out fully to zero stress level and partially to two different stress levels of 25 percent and 50 percent of peak stress. Stability point limit exhibits a unique stress-strain curve for full unloading but it could not be established for partial unloading. Common point limit was established for all unloading-reloading patterns considered, but its location depends on the stress level at which unloading is carried to. Common point curves were found to follow an exponential formula, while residual strains versus envelope strains can be expressed by a polynomial function of a single term. The relation between residual strain and envelope strain can be used to determine the stress level at which deterioration due to cyclic loading began.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.96-99
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• 2005

Fiber optic connector, ferrule, is a device to connect and align fiber optics cable on fiber-optic communication system. In this paper, Structural analysis was performed to analyze bed and frame structure of co-axial grinding machine. Deformation and modal analysis for natural frequency was performed using ANSYS Designspace program to analyze structural characteristics. New improved model of bed and frame structure was proposed based on initial basic model.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.559-560
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• 2006

Fiber optic connector, ferrule, is a device to connect and align fiber optics cable on fiber-optic communication system. In general $ZrO_2$ ceramic ferrule is manufactured by grinding process because the demands precision is very high. For the precision grinding machining, it is very important that structure of co-axial ferrule grinding system is optimized. In this paper, Structural analysis was performed to analyze bed and frame structure of co-axial grinding machine. Deformation and modal analysis for natural frequency was performed using ANSYS design space program to analyze structural characteristics. New improved model of bed and frame structure was proposed based on initial basic model. Therefore, we estimated the structural characteristics precision co-axial grinding machining system.

• Advances in concrete construction
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• 제6권6호
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• pp.585-610
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• 2018

In this study, vibration analysis of a concrete foundation-reinforced by $SiO_2$ nanoparticles resting on soil bed is investigated. The soil medium is simulated with spring constants. Furthermore, the Mori-Tanaka low is used for obtaining the material properties of nano-composite structure and considering agglomeration effects. Using third order shear deformation theory or Reddy theory, the total potential energy of system is calculated and by means of the Hamilton's principle, the coupled motion equations are obtained. Also, based an analytical method, the frequency of system is calculated. The effects of volume percent and agglomeration of $SiO_2$ nanoparticles, soil medium and geometrical parameters of structure are shown on the frequency of system. Results show that with increasing the volume percent of $SiO_2$ nanoparticles, the frequency of structure is increased.

• 기술사
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• 제44권1호
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• pp.44-47
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• 2011

Huge amount of energy produced by an underground nuclear test is released into the surrounding rock. Depending on the properties of the bed rock surrounding the detonation and overlaying it a variety of effects can occur. At some particular depth the increasing amount of material thrown upward is exactly balanced by the decreasing fraction escaping the crater, the crater volume reaches to a maximum. This depth is called the optimum depth of burial and varies somewhat with the geology of the site, being greater for less dense and structurally weaker material.