• 제목/요약/키워드: Super element

검색결과 229건 처리시간 0.02초

유한요소법을 이용한 Super-ROM 디스크 구조의 열 분포 해석 (Simulations of time dependent temperature distributions of Super-ROM disk structure using finite element method)

  • 안덕원;유천열
    • 정보저장시스템학회논문집
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    • 제1권2호
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    • pp.132-136
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    • 2005
  • It is widely accepted that the reading mechanism of Super-RENS(super-resolution near field structure) and Super-ROM(super-resolution read only memory) is closely related with non-linear temperature dependent material properties such as refractive indices, phase change. Furthermore, the dynamic change of the temperature distribution also an essential part of reading mechanism of Super-RENS/ROM. Therefore, the knowledge of the temperature distribution as a function a time is one of the important keys to reveal the physics of reading mechanism in Super-RENS/ROM. We calculated time-dependent temperature distribution in a 3-dimensional Super-ROM disk structure when moving laser beam is irradiated. With a help of commercial software FEMLAB which employed finite element method, we simulated the temperature distribution of ROM structure whose pit diameter is 120-nm with 50-nm depth. Energy absorption by moving laser irradiation, time variations of heat transfer processes, heat fluxes, heat transfer ratios, and temperature distributions of the complicate 3-dimensional ROM structure have been obtained.

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다단계 부분구조법을 이용한 코일스프링의 유한 요소 응력해석 I : 스프링 슈퍼요소 (Finite Element Stress Analysis of Coil Springs using a Multi-level Substructuring Method I : Spring Super Element)

  • 김진영;허훈
    • 한국자동차공학회논문집
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    • 제8권2호
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    • pp.138-150
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    • 2000
  • This study is concerned with computerized multi-level substructuring methods and stress analysis of coil springs. The purpose of substructuring methods is to reduce computing time and capacity of computer memory by multiple level reduction of the degrees of freedom in large size problems which are modeled by three dimensional continuum finite elements. In this paper, a super element has been developed for stress analysis of coil springs. The spring super element developed has been examined with tension and torsion simulation of cylindrical bars for demonstrating its validity. The result shows that the super element enhances the computing efficiency while it does not affect the accuracy of the results and it is ready for application to the coil spring analysis.

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회전 및 풍하중 가진 효과를 고려한 대형 풍력발전 로터의 효율적인 슈퍼요소 구조진동해석 (Efficient Super-element Structural Vibration Analyses of a Large Wind-turbine Rotor Blade Considering Rotational and Aerodynamic Load Effects)

  • 김동만;김동현;박강균;김유성
    • 한국소음진동공학회논문집
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    • 제19권7호
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    • pp.651-658
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    • 2009
  • In this study, computer applied engineering(CAE) techniques are fully used to efficiently conduct structural and dynamic analyses of a huge composite rotor blade using super-element. Computational fluid dynamics(CFD) is used to predict aerodynamic loads of the rotating wind-turbine blade. Structural vibration analysis is conducted based on the non-linear finite element method for composite laminates and multi-body dynamic simulation tools. Various numerical results are presented for comparison and the structural dynamic behaviors of the rotor blade are investigated herein.

Nonlinear seismic analysis of a super 13-element reinforced concrete beam-column joint model

  • Adom-Asamoah, Mark;Banahene, Jack Osei
    • Earthquakes and Structures
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    • 제11권5호
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    • pp.905-924
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    • 2016
  • Several two-dimensional analytical beam column joint models with varying complexities have been proposed in quantifying joint flexibility during seismic vulnerability assessment of non-ductile reinforced concrete (RC) frames. Notable models are the single component rotational spring element and the super element joint model that can effectively capture the governing inelastic mechanisms under severe ground motions. Even though both models have been extensively calibrated and verified using quasi-static test of joint sub-assemblages, a comparative study of the inelastic seismic responses under nonlinear time history analysis (NTHA) of RC frames has not been thoroughly evaluated. This study employs three hypothetical case study RC frames subjected to increasing ground motion intensities to study their inherent variations. Results indicate that the super element joint model overestimates the transient drift ratio at the first story and becomes highly un-conservative by under-predicting the drift ratios at the roof level when compared to the single-component model and the conventional rigid joint assumption. In addition, between these story levels, a decline in the drift ratios is observed as the story level increased. However, from this limited study, there is no consistent evidence to suggest that care should be taken in selecting either a single or multi component joint model for seismic risk assessment of buildings when a global demand measure such as maximum inter-storey drift is employed in the seismic assessment framework.

고층 아파트 외관 슈퍼그래픽의 시지각적 특성 및 평가 성향에 관한 연구 (A Study on Visual Characteristic & Evaluation of the Super Graphic of High-raised Apartment Housing)

  • 최석창;양소진;유창균;이청웅
    • 한국주거학회논문집
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    • 제14권6호
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    • pp.147-154
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    • 2003
  • This study examines and analyzes the current status, characteristics and properties of Super-Graphic as a visual element with Super Graphic designed on the wall of apartment housing, typifies them and explains the preference and evaluative structure by each type. The results of this study are as follows: According to color environment of Super-Graphic, N-tone colors are 21.4% and YR-tone colors are 14.5%. In the whole distribution, cold color tone is 41.4% and warm color tone is 37.2%. In the brightness, 72.9% of the entire Super Graphic use high brightness and in the saturation, 51.2% show low saturation, achromatic colors are 21.4% and high saturation is 16.5%. As a result of conducting SD test to analyze the preference of Super-Graphic, 'wonderful' is most negative variable, followed by 'heterogeneous', 'splendid', 'romantic' variety'. Positive variables are 'monotone', 'stable' and 'calm'. As a result of factor analysis to reveal the evaluative structure of Super Graphic image based on the above results, five factors including brightness, saturation, stability, harmony and ordered are extracted and it is considered that these are important variables to be reflected in designing Super Graphic in future.

Free transverse vibration of shear deformable super-elliptical plates

  • Altekin, Murat
    • Wind and Structures
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    • 제24권4호
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    • pp.307-331
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    • 2017
  • Free transverse vibration of shear deformable super-elliptical plates with uniform thickness was studied based on Mindlin plate theory using finite element method. Quadrilateral isoparametric elements were used in the paper. Sensitivity analysis was made to determine the influence of the thickness, the aspect ratio, and the shape of the plate on the natural frequency. Accuracy of the results computed in the current study was validated by comparing them with the solutions available in the literature. The results reveal that the frequencies of clamped super-elliptical plates lie in the range bounded by elliptical and rectangular plates irrespective of the aspect ratio, and furthermore, the frequency decreases if the super-elliptical power increases. A similar trend was observed for simply supported plates with high aspect ratio. The free vibration response for the first and the second symmetric-antisymmetric (SA) modes were found to be different for high aspect ratio. The results reveal that using insufficient number of degrees of freedom results in finding a totally different relation between the super-elliptical power and the frequency.

국부적 불연속을 가진 도파관의 고주파수 대역 파동 반사 및 투과 해석 기법 (A Numerical Method for Wave Reflection and Transmission Due to Local Non-Uniformities in Waveguides at High Frequencies)

  • 유정수
    • 한국음향학회지
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    • 제29권5호
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    • pp.314-324
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    • 2010
  • 도파관 (waveguide structures)에 지지구조 또는 균열과 같은 국부적 불연속이 존재하는 경우, 도파관을 따라 전파되는 파동은 이러한 국부적 불연속으로 인해 반사가 발생한다. 빔과 같이 단면의 형상이 단순한 도파관에서는 국부적 불연속에 의한 저주파수 대역 반사 및 투과 특성을 스펙트럴요소(spectral element, SE)와 유한요소(finite element, FE)를 연결한 스펙트럴요소/유한요소법 (SE/FE method)으로 해석 할 수 있다. 그러나 도파관의 단면 형상이 복잡하거나 또는 고주파수 대역 해석에서는 빔 이론에 근거한 스펙트럴 요소를 이용하는 것이 부적합하다. 본 논문에서는 고주파수 대역 파동 반사 및 투과 특성 해석을 위해 스펙트럴요소 대신 스펙트럴수퍼요소 (spectral super element, SSE)를 도입하고, 이를 유한요소와 결합시킨 SSE/FE 방법을 제안한다. 이 방법은 도파관 모델링에 스펙트럴 수퍼요소를 이용하므로 레일과 같이 단면의 형상이 복잡한 도파관의 고주파수 대역 해석에 적합하다. 본 논문에서는 SSE/FE 해석에 필요한 반무한 SSE(semi-infinite spectral super element)에 대한 정식화를 먼저 수행하고, 이를 FE로 모델링한 국부적 불연속 구간과 연결하여 SSE/FE 모델을 구성하였다. 이 방법의 적용 예로써 단순 형상의 국부적 결함이 존재하는 철로 레일에 대하여 고주파수 대역 파동반사 및 투과계수를 계산하고 그 결과를 살펴보았다. 또한, 입사된 파워가 보존되어야 한다는 조건을 이용해 SSE/FE 방법의 수치오차를 추정하였다.

모드III 탄성 균열문제 해석에 대한 연구 (Elastic Analysis of the Mode III Crack Problem)

  • 김윤영;윤민수
    • 대한기계학회논문집
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    • 제19권4호
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    • pp.941-949
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    • 1995
  • An efficient method based on analytic solutions is applied to solve anti-plane Mode III crack problems. The analytic technique developed earlier by the present authors for Laplace's equation in a simply-connected region is now extended to general Mode III crack problems. Unlike typical numerical methods which require fine meshing near crack tips, the present method divides the cracked bodies, typically non-convex or multiply-connected, into only a few super elements. In each super element, an element stiffness matrix, relating the series coefficients of the traction and displacement, is first formed. Then an assembly algorithm similar to that used in the finite elements, is first formed. Then an assembly algorithm similar to that used in the finite elements, is developed. A big advantage of the present method is that only the boundary conditions are to be satisfied in the solution procedure due to the use of analytic solutions. Several numerical results demonstrate the efficiency and accuracy of the present method.

굽힘효과를 고려한 박막 유한요소에 의한 단면 성형해석 (Sectional forming analysis by membrane finite elements considering bending effects)

  • 김준보;이광병;금영탁
    • 대한기계학회논문집A
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    • 제22권3호
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    • pp.493-503
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    • 1998
  • The sectional forming analysis considering bending effects from the geometrically deformed shape of two linear membrane finite elements(called super element) was performed under plane strain assumption for analyzing forming processes of an arbitrarily shaped draw-die. For the evaluation of bending effects, the bending equivalent forces are calculated from the bending moment computed using the changes in the interior angle at the middle node of super element, and are agumented to the membrane stretch forces. In order to verify the validity of the bending formulation, the simulation results for the stretch, draw, and bend sections were compared with membrane analysis results and measurements.