• 해양환경안전학회지
• /
• 제20권2호
• /
• pp.234-240
• /
• 2014

본 연구에서는 허니컴 패널의 지배방정식을 이용하여 경계행렬식을 유도하였고, 이를 전달행렬법에 적용하여 허니컴 패널을 적용한 차음패널에 대한 해석 이론을 정립하였다. 또한, 허니컴 패널을 선박용 차음패널의 표면재로 적용하여 차음성능을 분석하였고, 철판을 표면재로 적용한 기존의 선박용 차음패널과 차음성능을 무게 당 감음량 기준으로 비교 분석하였다. 그 결과, 허니컴 패널의 차음성능이 0.35 mm 철판에 비해 STC 기준으로 2dB 높게 나와 허니컴 패널을 적용한 차음패널의 차음성능이 철판을 사용한 차음패널에 비해 무게 당 감음량을 고려할 시 우수하다는 것을 확인하였다. 또한, 허니컴 패널을 표면재로 사용한 차음패널의 면밀도가 철판을 사용한 차음패널에 비해 약 $5.2kg/m^2$ 가볍게 나타났고, 이는 약 31.7 % 무게 감소를 의미한다.

• International Journal of Aeronautical and Space Sciences
• /
• 제17권4호
• /
• pp.476-490
• /
• 2016

This paper defines mode shape function of a composite solar panel assumed as Kirchhoff-Love plate for considering a torsional mode of composite solar panel. It then goes on to define dynamic model of a high-agility satellite considering the flexibility of composite solar panel as well as stiffness of a solar panel's hinge using Lagrange's theorem, Ritz method and the mode shape function. Furthermore, this paper verifies the validity of dynamic model by comparing numerical results from the finite element analysis. In addition, this paper performs a dynamic response analysis of a rigid satellite which includes only natural modes for solar panel's hinges and a flexible satellite which includes not only natural modes of solar panel's hinges, but also structural modes of composite solar panels. According to the results, we confirm that the torsional mode of solar panel should be considered for the structural design of high-agility satellite. Finally, we performed optimization of high-agility satellite for minimizing mass with solar panel's area limit using the defined dynamic model. Consequently, we observed that the defined dynamic model for a high-agility satellite and result of the optimal design are very useful not only because of their optimal structural design but also because of the dynamic analysis of the satellite.

• 한국산학기술학회논문지
• /
• 제10권1호
• /
• pp.39-45
• /
• 2009

디스플레이 장치에서 기존의 CRT는 곡면이며 무겁고 큰 부피 때문에 LCD, PDP와 같은 평판디스플레이(FPD)로 대체되고 있다. FPD는 $0.6{\sim}0.8mm$ 두께의 대면적 글래스에 여러 공정을 거친 후에 최종 제품 규격으로 절단하여 제작하기 때문에 글래스의 면적이 크면 클수록 FPD의 생산성이 높다는 밀접한 관계를 갖는다. 따라서 FPD 제조 업계에서는 글래스 면적을 증가시키기 위하여 노력하고 있다. 7세대 글라스($2,220mm\;{\times}\;1,870mm\;{\times}\;0.7mm$)를 대상으로 유한요소해석 및 유동해석을 통하여 이송장치, 배급장치, 수평/경사 변환장치 및 제어장치로 구성된 비접촉 공기부상 이송시스템을 개발하였다. 본 개발에서 확보한 설계기술을 통하여 글라스의 크기가 대형화 되더라도 관련 이송장비를 보다 쉽게 제작하여 적용할 수 있다.

• 노동경제논집
• /
• 제32권2호
• /
• pp.95-124
• /
• 2009

본 연구는 외환위기 이후 상장제조기업의 생산성 추이 및 교육훈련효과를 분석하였다. 분석 결과, 외환위기 이후 상장제조기업은 시간이 흐를수록 저 생산성 국면에 빠지게 되었으며, 그 과정에서 상장제조기업의 고용 없는 성장, 물적 투자 없는 성장, 인적자본투자 없는 성장 현상이 관찰되었다. 그리고 생산성이 높은 기업의 고용비중이 늘고, 낮은 기업의 고용비중이 주는 효율적인 노동시장이 거의 작동하지 않았다. 또한 교육훈련이 생산성에 미치는 영향을 분석해 보기 위해 동적 패널 분석을 실시할 경우 교육훈련의 과소투자가 발생하고 있음에도 불구하고 교육훈련의 생산성에 대한 지나치게 높은 긍정적 효과가 나타나는 모순적 현상이 상당 부분 해결되었다.

• 대한조선학회논문집
• /
• 제52권5호
• /
• pp.380-386
• /
• 2015

Panel methods are useful tools for analyzing fluid-flow around a wing section. It has the advantage of fast and accurate calculation, compared to other CFD Methods such as RANS solvers. This paper suggests a piecewise linear panel method in order to improve accuracy of existing panel methods by changing the piecewise constant singularity strength to linear singularity strength(for dipole strength). The piecewise linear panel method adopts the linear distribution of singularity strength, while control point is located at the node of each panel. Formulation of the piecewise linear panel method is given, and some calculation results are shown for typical wing sections.

• 한국강구조학회 논문집
• /
• 제9권4호통권33호
• /
• pp.683-695
• /
• 1997

본 연구는 강제 라멘교각 접합부 panel zone의 전단거동특성에 대하여 검토한 것이다. 여기에서는 접합부 시험체 20개에 대한 재하실험 결과와 3가지의 FEM해석 모델에 대한 결과를 제시 하였다. 이와같은 실험및 해석결과를 비교 검토한 결과, panel zone의 강도와 변형 성능은 단면적비와 전단좌굴등에 의하여 감소하는 경향을 보이고 있음을 알 수 있었다. 따라서 본 연구에서는 이상의 결과를 기초로 panel zone의 강도와 변형성능에 대한 새로운 평가식을 제안하였으며, 또한 기존의 라멘교각 접합부에 대한 변형성능에 관해서 검토하였다.

• 설비공학논문집
• /
• 제3권4호
• /
• pp.276-285
• /
• 1991

The transient heat transfer characteristics in the radiant heating panel were predicted by numerical analysis. Thermal behaviors of panel, such as temperature distributions in panel and convective and radiative heat fluxes in panel surface with respect to time were obtained. Heating hours per day, rate of energy supplied and maximum temperature differences at panel surface were also compared for several important parameters. The performance and thermal comfort of heating panel were studied and compared for various operating and design conditions such as pipe pitch, pipe location, pipe diameter and flow rate of hot water for the purpose of producing useful data, which can be used for the test and decision of efficient operating condition of the conventional heating systems or the optimal design of the new panel heating systems.

• 대한건축학회연합논문집
• /
• 제21권4호
• /
• pp.139-146
• /
• 2019

The purpose of this study is to propose the building design guideline considering photovoltaic panel installation through the analysis of relevant guidelines from home and abroad in terms of building design and solar panel installation. Conclusions can be summarized as followings; Considerations in building design : selection of the site with high solar accessibility, avoidance of the shade from the adjacent building & trees, south facing orientation of solar panel in building design, removal of shade on the solar panel from the part of building itself, load consideration of solar panel & fixing materials, safe passage securement for solar system maintenance, and planning of piping and mechanical room for solar system. Considerations in solar panel installation : harmonizing of solar panel with surrounding environment, unity of solar panel orientation & slope, regular maintenance of solar system, (in case of flat roof installation) solar panel installation afloat over the roof, installation area within the roof floor, and lower than parapet height, (in case of sloped roof installation) solar panel installation parallel with the roof slope, ventilation space securement below the panel, installation area within the roof surface, and similar material installation in empty space.

• 소성∙가공
• /
• 제20권7호
• /
• pp.512-517
• /
• 2011

TRB(Tailor Rolled Blank) is an emerging manufacturing technology by which engineers are able to change blank thickness continuously within a sheet metal. TRB door inner panels with required larger thicknesses can be used to support localized high loads. In this study, the aluminum alloy 5J32 TRB sheet is used for a door inner panel application. The TRB material properties were varied by using three heat treatment conditions. In order to predict the failure of the aluminum TRB during simulation, the forming limit diagram, which is used in sheet metal forming analysis to determine the criterion for failure, was investigated. Full-field photogrammetric measurement of the TRB deformation was performed with an ARAMIS 3D system. A FE model of the door inner panel was created using Autoform software. The material properties obtained from the tensile tests were used in the numerical model to simulate the door inner of AA 5J32 for each heat treatment condition. After finite element analysis for the evaluation of formability, a prototype front door panel was manufactured using a hydraulic press.

• 한국전산유체공학회지
• /
• 제19권4호
• /
• pp.37-44
• /
• 2014

A detailed satellite panel thermal model composed of more than thousands nodes can not be directly integrated into a spacecraft thermal model due to its node size and the limitation of commercial satellite thermal analysis programs. For the integration of the panel into the satellite thermal model, a reduced thermal model having proper accuracy is required. A thermal model reduction method was developed and validated by using a geostationary satellite panel. The temperature differences of main components between the detailed and the reduced thermal model were less than $1^{\circ}C$ in steady state analysis. Also, the dynamic responses of the detailed and the reduced thermal model show very similar trends. Thus, the developed reduction method can be applicable to actual satellite thermal design and analysis with resonable accuracy and convenience.