• 한국군사과학기술학회지
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• 제11권1호
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• pp.57-65
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• 2008

Superplastic forming/diffusion bonding(SPF/DB) processes with inner contact were analyzed using a 3-D rigid visco-plastic finite element method. A constant-triangular element based on membrane approximation and an incremental theory of plasticity are employed for the formulation. The hierarchical search algorithm for the contact searching has been applied. The algorithms for contact force processing were designed to handle equally well contact between deformable bodies, as well as rigid bodies. The plate of three and four sheets for 3-D SPF/DB model are analyzed using the developed program. The validity for the analysis is verified by comparison between analysis, experiment and results in the literature.

• Advanced Composite Materials
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• 제16권1호
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• pp.31-44
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• 2007

The purpose of this study is to improve the examining and understanding of the bonding behavior of Fiber Reinforced Polymer (FRP) sheets bonded to concrete blocks and steel plates under fatigue loading. First, a series of experimental investigations is summarized in the paper. The fatigue behavior of bonding surface between FRP sheets and concrete is finally characterized by the conducted P-S-N diagram representing the relationship among the probability of FRP debonding (P), the bond stress amplitudes (S), and the number of cycles (N) at debonding on a semi-logarithmic scale. The different debonding modes for various fracturing surface are also investigated and evaluated.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.836-840
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• 2006

Design optimization of layered plates bonding process is conducted to achieve high product quality by considering uncertainties in a manufacturing process. During the cooling process of the sequential sub-processes, different thermal expansion coefficients lead to residual stress and displacement. thus resulting in defects on the surface of the adherent. So robust process optimization is performed to minimize the residual stress mean and variation of the assembly while constraining the distortion as well as the instantaneous maximum stress to the allowable limits. In robust process optimization, the dimension reduction (DR) method is employed to quantify both reliability and quality of the layered plate bonding. Using this method. the average and standard deviation is estimated. Response surface is constructed using the statistical data obtained by the DRM for robust objectives and constraints. from which the optimum solution is obtained.

• 박물관보존과학
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• 제26권
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• pp.119-142
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• 2021

금동은제식리는 무령왕릉에서 출토된 무령왕의 식리로 결실된 부분이 많아 재조사의 필요성이 꾸준히 제기되었다. 이에 과학적인 보존처리 및 분석을 진행하여 제작기법을 연구하였다. 보존처리는 형태 복원 및 편 접합에 중점을 두고 실시하였다. 그 결과, 우측 식리 상연과 뒤축 일부 편을 접합하여, 결합방법 및 발등 결합에 사용된 원두정의 개수를 확인하였다. 성분 분석결과, 외판 등은 순동에 수은 아말감 금도금을 한 것으로 추정되며, 내판은 순은을 사용하였다. 금동은제식리의 주문양은 봉황문, 연화문, 6엽 화문이며, 전체적으로 연화문의 비율이 높다. 각 판의 결합은 영락사, 금동사, 원두정, 사면정을 사용하였다. 내·외판 결합은 영락사를 사용하였는데, 내측판의 중앙과 후면에는 금동사로만 결합하여 장식 기능과 결합 기능을 구분하여 사용한 것으로 추정된다. 또한 제작과정에서 금동제판과 은제판의 외면에는 광쇠질한 흔적이 확인되지만, 은제판의 내면에서는 확인되지 않아 내면보다 외면의 마무리에 중점을 둔 것으로 추정된다.

• 한국산학기술학회논문지
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• 제9권1호
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• pp.9-15
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• 2008

모꾸메가네는 나무결 모양을 낼 수 있는 고부가가치가 가능한 장신구 소재이며 서로 다른 금속을 가공하기 위해 융점이 다른 두 가지 이상 금속을 적층하여 붙인 잉곳 제작이 필수적이다. 기존의 모꾸메가네용 잉곳은 숯을 이용한 환원성 분위기에서 경험에 근거한 육안 판별로 만들어져서 접합의 신뢰성과 후속 가공 도중 층간 분리가 일어나는 분제가 있었다. $900^{\circ}C$에서 2.5kg의 압력을 가하면서 진공 열처리로를 이용하여 90% 이상 접합율이 가능한 조건을 확인하였다. 계면에서의 계면 확산계수가 통상의 벌크 확산계수보다 100배 향상되는 것을 확인하였고 이종 접합시에 계면 확산계수를 확인하여 $700^{\circ}C$의 저온에서 10분동안 진공열처리, 90% 이상 접합율을 가진 모꾸메가네용 잉곳을 성공적으로 제조하였다. 제조된 잉곳으로 핸드폰 외장용 모꾸메가네 시작품을 성공적으로 제조할 수 있었다.

• 한국정밀공학회지
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• 제21권2호
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• pp.195-202
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• 2004

This paper presents the fabrication and evaluation of mechanical behavior for a peristaltic micropump by flow simulation. The valve-less micropump using the diffuser/nozzle is consists of the lower plate, the middle plate, the upper plate and the tube that connects inlet and outlet of the pump. The lower plate includes the channel and the chamber, and the plain middle plate are made of glass and actuated by the piezoelectric translator. Channels and a chamber on the lower plate are fabricated on high processability silicon wafer by the DRIE(Deep Reactive Ion Etching) process. The upper plate does the roll of a pump cover and has inlet/outlet/electric holes. Three plates are laminated by the aligner and bonded by the anodic bonding process. Flow simulation is performed using error-reduced finite volume method (FVM). As results of the flow simulation and experiments, the single chamber pump has severe flow problems, such as a backflow and large fluctuation of a flow rate. It is proved that the double-chamber micropump proposed in this paper can reduce the drawback of the single-chamber one.

• Steel and Composite Structures
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• 제17권5호
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• pp.601-621
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• 2014

Repairing and strengthening structural members by bonding composite materials have received a considerable attention in recent years. The major problem when using bonded FRP or steel plates to strengthen existing structures is the high interfacial stresses that may be built up near the plate ends which lead to premature failure of the structure. As a result, many researchers have developed several analytical methods to predict the interface performance of bonded repairs under various types of loading. In this paper, a numerical solution using finite - difference method (FDM) is used to calculate the interfacial stress distribution in beams strengthened with FRP plate having a tapered ends under thermal loading. Different thinning profiles are investigated since the later can significantly reduce the stress concentration. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both beam and bonded plate. The shear correction factor for I-section beams is also included in the solution. Numerical results from the present analysis are presented to demonstrate the advantages of use the tapers in design of strengthened beams.

• 소성∙가공
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• 제27권5호
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• pp.267-275
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• 2018

The clad sheet material is produced by a roll-bonding process of one or more materials with different properties. Good formability of clad sheet material is an essential property in to deform a clad metal sheet into a part or component. Performance of the clad sheet material largely depends on interfacial bond strength between different materials. In this study, interfacial bond strength of STS/Al clad sheet was analyzed by varying experimental parameters using a blanking process. Experimental parameters are the punching speed, clearance, and stacking order of plate materials. In addition, blanking test results were compared with bond strengths measured by the T-peel test, that analyzes interface bonding strength of the standard clad sheet. The blanking process was analyzed by the finite element method under the sticking condition of interface of different materials, and experimental results and analysis results were compared.

• Journal of Information Display
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• 제3권1호
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• pp.11-16
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• 2002

This paper presents a study on the tubeless Plasma Display Panel (PDP) packaging using glass-to-glass electrostatic bonding with intermediate amorphous silicon. The bonded sample sealing the mixed gas with three species showed high strength ranging from 2.5 MPa to 4 MPa. The glass-to-glass bonding for packaging was performed at a low temperature of $180^{\circ}C$ by applying bias of 250 $V_{dc}$ in ambient of mixed gases of He-Ne(27 %)-Xe(3 %). The tubeless packaging was accomplished by bonding the support glass plate of $30mm{\times}50mm$ on the rear glass panel and the capping glass of $20mm{\times}20mm$. The 4-inch color AC-PDP with thickness of 8 mm was successfully fabricated and fully emitted as white color at a firing voltage of 190V.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.209-219
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• 1997

The research of the dentin bonding system was mainly on the chemistry and bonding strength. And in vitro assessement of biocompatibility of dentin bonding system was not completely developed. The purpose of this study was to evaluate the cytotoxic effect of several dentin primers. Scotchbond Multi-Purpose (3M Dental Products. USA). Gluma (BayerDental. Germany). All-Bond (Bisco. USA). ProBond (CaulkDensply, USA) and VeridonFil (Dongyang Nylon. Korea) were included. Cytotoxicity was tested using MTT cell viability test. 0.5 ul. 1 ul. 2 ul and 10 ul of each primer were added to the 96 well plate of incubated L929 cell lines. After 30-minute. 1. 4. 24 and 72-hour exposures. absorbance of L929 cells was observed with ELISA reader. All data were analyzed using t-test. All primers showed cytotoxicity on L929 cells under every conditions used in this study. Absorbance of L929 cells was decreased by time. Scotch bond group exhibited the lowest absorbance value in all exposure time and value.