• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.55-56
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• 2015

This study is corroborated as a fundamental resource to develop structural lightweight paste containing silica fume as a part of cement. Paste using foaming agent is generated much foam and decreased density of paste. This study is measured at 0.8% of foaming agent dosage but over 0.8% of foaming agent dosage raise density of paste because of interconnection with foam. Also, FEM analysis using SEM image is confirmed correspondence of between Elastic modulus of experiment and FEM analysis.

• 한국구조물진단유지관리공학회 논문집
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• 제10권1호
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• pp.223-230
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• 2006

본 논문에서는 염해에 의하여 열화된 철근콘크리트 구조물의 보수 LCC평가 방법에 대하여 연구를 수행하였다. 또한, 철근콘크리트 구조물의 목표내용년수 동안에 건설초기 공법과 염해보수 공법을 포함한 보수 LCC를 평가하기 위하여 콘크리트내로의 염소이온 침투를 FEM 해석으로 실시함으로써 보수횟수를 결정하였다. 그 결과, 염해 보수 횟수는 보수재의 종류 및 보수방법을 고려한 FEM해석을 통하여 철근위치에서의 염소이온 농도와 철근부식 임계염소이온 농도를 비교함으로써 산정할 수 있었으며, 염해 보수 횟수를 이용하여 목표내용년수 동안의 보수 LCC를 산정하는 것이 가능하였다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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• pp.28.4-29
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• 2008

The aim of the test is to provide an experimental basis to validate the prediction of the FEM for high frequency jitter analysis due to reaction wheel. The principle is to measure structural transfer functions between the input disturbances at RWA base plate and the accelerations near the end tips of payload, in a configuration close to the operational model. The spacecraft shall have to be suspended, in order to be representative of on-orbit boundary conditions. The results of the test shall be compared to the output of the FEM analysis, and if needed, local upgrades of the FEM and/or margin policy shall be defined in order to guarantee a good test/FEM consistency. Test results were compared with the transfer functions of the FEM, which is globally tuned based on the results of vibration test and consequently have lower damping coefficients values than 1% in the frequency range of 60~200Hz. The damping coefficients estimated from the figures of FRF test results are different from the theoretical FEM, but the magnitude trend of FRF of the test results is somewhat similar with the analytical, it is expected that the overall jitter effect of final estimation is nearly same with the preliminary analysis result in which the damping coefficients were assumed to be 1% for all modes in FEM.

• 한국정밀공학회지
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• 제16권6호
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• pp.114-122
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• 1999

By using the FEM, a method for the stress analysis of the presented dies has been proposed. In this method, FEM and Lame equation are used for the analysis of the die insert and the stress ring, respectively. The proposed method includes the calculation of the contact pressure between the die insert and the stress ring. To show the validity, the proposed method has been applied to the simple test problem. The results of the stress analysis have been compared with the results of ANSYS, a commercial FE-code. Cold extrusion has been simulated by using the rigid-plastic FEM and the results of the deformation analysis have been used as the input of the die structure analysis. The stress states of the prestressed extrusion die have been obtained. The stress analysis of the die insert with stress rings has also been performed during extrusion.

• 한국정밀공학회지
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• 제15권9호
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• pp.68-74
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• 1998

The ESPI(Electronic Speckle Pattern Interferometry) is a real time, full-field, non-destructive optical measurement technique that allows static and dynamic deformation analysis and surface shape measurements of engineering structures. e .g. turbine blades. vehicle engine components, body panels, etc. This technique is very similar to holographic interferometry, but uses a solid static camera and an image processing board for recording and digital processing of speckle patterns. In this paper it is presented that FEM results for the free vibration of symmetrically laminated composite as [30/-30/90]s. The natural frequencies of laminated composite rectangular plates having the particular boundary condition are experimentally obtained. In order to demonstrate the validity of the experiment, FEM analysis using ANSYS was performed and natural frequencies experimentally obtained is compared with calculation by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.

• 한국생산제조학회지
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• 제19권4호
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• pp.498-503
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• 2010

The main purpose of this study strongly concerned micro machining error estimation by using FEM analysis of tool deflection shapes in micro flat end-milling process. For the precision micro flat end-milling process, analysis of micro cutting errors is mandatory. In general, tool deflection is a major factor which causes cutting error and limits realization of the high-precision cutting process. Especially, in micro end-milling process, micro tool deflection generates very serious problems in contrast to macro tool deflection. Methods which deal with compensation of cutting error by tool deflection in macro end-milling process have been studied plentifully but, few researches transact with micro scaled cutting tool deflection in micro cutting process. Therefore, the trend of micro tool deflection was estimated by using FEM analysis in this paper. Cutting forces were acquired by micro dynamometer and these were utilized in FEM analysis. In order to verify FEM analysis results, micro machining processes were carried out and real machined profiles were compared with FEM results. Finally through the proposed approach well suited FEM results were obtained.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.401.2-401
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• 2002

An unconstrained tuning fork with a 3-D model has been numerically analyzed by Finite Element Method (FEM) and Boundary Element Method (BEM). The first three natural frequencies were calculated by the FEM modal analysis. Then the change of the modal frequencies was examined with the variation of the tuning fork length and width. (omitted)

• 한국구조물진단유지관리공학회 논문집
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• 제18권1호
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• pp.19-30
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• 2014

본 연구에서는 강주탑 기부와 기초콘크리트 연결 구조에 대해서 국내에서 특수교량의 강주탑 기부 설계에 보편적으로 적용하고 있는 명석해협대교(明石海峽大橋) 시방기준과 비선형 FEM 해석결과를 비교하였다. 명석해협대교(明石海峽大橋) 시방기준은 1970년도에 만들어진 일본 기준으로 주탑 기부와 PS 강봉 및 기초콘크리트를 스프링으로 선형 모델링하여 설계하는 방법으로서 43년이 지난 지금까지도 간편성을 이유로 이 기준을 적용하고 있다. 그러나 비선형 FEM 해석결과의 비교를 통해 특수 장대교의 강주탑 기부의 해석 및 설계에 이 기준을 적용하는 것은 여러 가지 문제점이 있음을 알 수 있었으며, 풍하중, 지진하중에 주요하게 저항하면서도 다양한 부재들로 복잡하게 연결된 강주탑 기부에 대해서는 한계상태설계법으로 발전하려는 현 시대에 맞추어 실제 거동을 반영하는 비선형 FEM해석을 적용해야 할 것이다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.335-338
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• 2003

Flexural test and parametric study by FEM analysis on 6.0m long reinforced concrete beams strengthened by GFRP are reported in these tests. The selected variables are strengthened plate length, plate thickness. The effects of these variables are discussed. The results generally indicate that the flexural strength of strengthened beams is increased. The results of FEM analysis show that the more strengthening GFRP is the more stress of GFRP is decrease when failure mode is peeling failure.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.388-392
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• 1995

The Electronic Speckle Pattern Interferometry(ESPI) has been applied to many technical problems such as deformation and displacement measurement, strain visualization and surface roughness monitoring. Composite materials have various complicated characteristics depending on the ply materials,ply orientations,ply stacking sequences and boundary conditions. Therefore, it is difficult to analyze composite material. For efficient use of composit materials in engineering applications, the dynamic behavior such as, natural frequencies and modal patterns should be identified. This studying presents FEM results for the free vibration of symmetrically laminated composite as [30/-30/90] $_{s}$. The natural frequencies of laminated composite rectangular plates having the boundary condition(:2-edge clamped) are experimentally obtained. In order to demonstrate the validity of the experiment,FEM analysis using ANSYS was performed and natural frequencies experimentally obtained is compared with calculated by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.t.