• 제목/요약/키워드: finite-element modeling

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Modeling and Numerical Investigation of the Biomechanical Interaction for Human-Rifle System

  • Chae, Je-Wook;Lee, Young-Shin
    • Journal of Mechanical Science and Technology
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    • v.18 no.12
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    • pp.2069-2079
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    • 2004
  • This paper represents the description of a complex mathematical model of biomechanical interaction for human-rifle system during shooting. The model is developed by finite element method using bar elements. And three typical shooting positions, i.e. standing, kneeling and prone are used. Characteristics of interior/exterior ballistics and behaviors of human-rifle system are evaluated by this model, which takes into account the influence of environment, bullet, powder, barrel geometry parameters and anthropological parameters. The results of this study can be applied to anthropology, biomechanics, medical science, gait analysis, interior ballistics and exterior ballistics.

A study on the estimation method of vibration characteristics of marine engines below 7-cylinder based on a test (실험 기반 7기통 이하 선박용 엔진 진동 특성 예측 방법에 관한 고찰)

  • Hwang, Sang-Jae;Kim, Hae-Seung;Kim, Myoung-Soo;Kim, Hyung-Jin;Kim, Ue-Kan
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2011.10a
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    • pp.59-59
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    • 2011
  • H-mode or X-mode predominates in marine engines according to the number of cylinder. Generally, H-mode noticeably happen in the engine below 7-cylinder and X-mode remarkably happen above 8-cylinder in the engine operating range. Until now, FEA (Finite Element Analysis) of 3D engine model has been mainly used to estimate the engine vibration but it is very time consuming for simulation and difficult to model simplification. Furthermore, the accuracy of simulation shows a marked difference according to modeling method. Therefore it is very difficult to have contentable result from FEA for beginners and laymen. In this paper, the estimation method based on a test has been suggested to solve the difficulty.

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An lnvestigation of the thermoelastic Behavior in Short Fiber Reinforced Composite Materials (단섬유 보강 복합재료에서의 열탄성 거동에 관한 해석)

  • 김홍건
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.6 no.3
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    • pp.89-95
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    • 1997
  • A simulation to investigate the thermal behavior in short fiber or whisker reinforced composite materials has been performed for the application to the thermoelastic stress analysis using Finite Element Method (FEM). To obtain the internal field quantities of composite material, the procedure of micromechanical modeling and the principle of virtual work were implemented. For the numerical illustration, an aligned axisymmetric single fiber model has been employed to assess field quantities. It was found that the proposed simulation methodology for thermoelastic stress analysis is applicable to the complicated inhomogeneous solid for the investigation of micromechanical thermoelastic behavior.

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The thermal conductivity analysis of the SOI/SOS LIGBT structure (Latch up 전후의 SOI(SOS) LIGBT 구조에서의 열전도 특성 분석)

  • Kim, Je-Yoon;Kim, Jae-Wook;Sung, Man-Young
    • 한국컴퓨터산업교육학회:학술대회논문집
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    • 2003.11a
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    • pp.79-82
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    • 2003
  • The electrothermal simulation of high voltage LIGBT(Lateral Insulated Gate Bipolar Transistor) in thin Silicon on insulator (SOI) and Silicon on sapphire (SOS) for thermal conductivity and sink is performed by means of MEDICI. The finite element simulations demonstrate that the thermal conductivity of the buried oxide is an important parameter for the modeling of the thermal behavior of silicon-on-insulator (SOI) devices. In this paper, using for SOI LIGBT, we simulated electrothermal for device that insulator layer with $SiO_2$ and $Al_2O_3$ at before and after latch up to measured the thermal conductivity and temperature distribution of whole device and verified that SOI LIGBT with $Al_2O_3$ insulator had good thermal conductivity and reliability.

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Modeling Creep Behavior and Life by Damage Mechanics (손상역학에 의한 크리프 거동 및 수명 모델링)

  • Sin, Chang-Hwan;Jeong, Il-Seop;Chae, Yeong-Seok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.7 s.178
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    • pp.1833-1840
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    • 2000
  • Commercially pure copper is tested to obtain creep curves at 2500C. Constitutive relations adopting continuum damage mechanics concept is found to be appropriate to model the creep defor mation up to the tertiary stage. Microscopic observation by SEM reveals that creep condition induces cavities and microcracks subsequently. The constitutive equations along with evaluated creep parameters are implemented into finite element analysis code. The analysis reproduces creep curves under step loading as well as constant loading with reasonable accuracy. Distribution and evolution of damage under creep loading are numerically simulated for two different types of notched specimen. Predicted creep life agrees quite well with rupture test results. The influence of mesh size at notch tip on rupture time prediction is studied, and a degree of refinement is suggested for the specific notched specimens.

Design and Structural Analysis of Duck Breeding System (오리 사육장치의 설계 및 구조해석)

  • 이종선;홍석주
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.4 no.4
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    • pp.418-421
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    • 2003
  • This study is object to design and souctural analysis of duck breeding system. Design tool is Auto CAD and souctural analysis of duck breeding system using result from ANSYS Code. The finite element model was developed to compute the stress, strain and displacement for duck breeding system. This structural analysis results, many variables such as boundary condition, constraint condition and load condition are considered.

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A study of Dielectric Strength of Spacer for Tap Changer in a $SF^6 $ Gas Insulated Transformer ($SF^6 $ 가스변압기의 탭절환기용 스페이서의 절연내력에 관한 연구)

  • Heo, U-Haeng;Ha, Yeong-Sik;Hong, Jeong-Gyun;Kim, Gyu-Tak
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.11
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    • pp.556-562
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    • 2001
  • Spacer is used between main tank and auxiliary tank for on load tap changer in gas insulated power transformer. This paper deals with electrical design of spacer and discusses different analysis method of between 2D FEM(finite element method) and 3D FEM. To design spacer, we modeled structure of two kind of coaxial cylinders of spacer conductors and analysised electric field of spacer at impulse and induced test voltage condition. Spacer has 13 conductors and electric field was changed according to arrangement of conductors. We could find out arrangement of conductors at which electric stress is minimum. And this arrangement was satisfied with actual test conditions.

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Efficiency Evaluations of Synchronous Reluctance Motor Using Coupled FEM & Preisach Modelling (프라이자흐 모델이 결합된 유한요소해석 및 실험을 통한 동기형 릴럭턴스 전동키의 효율 특성 평가)

  • Lee, D.D.;Lee, M.M.;Sim, J.M.;Lee, J.H.
    • Proceedings of the KIEE Conference
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    • 2002.11d
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    • pp.49-51
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    • 2002
  • This paper deals with the efficiency evaluations in a synchronous reluctance motor (SynRM) using a coupled transient finite element method (FEM) and Preisach modeling, which is Presented to analyze the characteristics under the effect of saturation and hysteresis loss. The focus of this paper is the efficiency evaluation relative to hysteresis loss, copper loss, etc. on the basis of speed, load condition in a SynRM. Computer simulation and experimental result for the efficiency using dynamometer show the propriety of the proposed method.

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CFD Simulation Tool for Anode-Supported Flat-Tube Solid Oxide Fuel Cell

  • Youssef M. Elsayed.;Lim, Tak-Hyoung;Song, Rak-Hyun;Lee, Seung-Bok;Shin, Dong-Ryul
    • Journal of the Korean Electrochemical Society
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    • v.9 no.4
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    • pp.151-157
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    • 2006
  • A two-dimensional numerical model to study the performance of anode-supported flat-tube solid oxide fuel cell (SOFC) far the cross section of the cell in the flow direction of the fuel and air flows is developed. In this model a mass and charge balance, Maxwell-Stefan equation as well as the momentum equation by using, Darcy's law are applied in differential form. The finite element method using FEMLAB commercial software is used for meshing, discritization and solving the system of coupled differential equations. The current density distribution and fuel consumption as well as water production are analyzed. Experimental data is used to verify a predicted voltage-current density and power density versus current density to judge on the model accuracy.

Contour based Algorithms for Generating 3D Models from CT Images (CT 이미지로부터 3차원 모델 생성을 위한 contour 기반 알고리즘)

  • 류재헌;김현수;이관행
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.4
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    • pp.174-182
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    • 2003
  • Recently, medical imaging has taken interest on CAD based solution for anatomical part fabrication or finite element analysis of human body. In principle, contours representing object boundary are obtained through image processing techniques. Surface models are then approximated by a skinning method. For this, various methods should be applied to medical images and contours. The major bottleneck of the reconstruction is to remove shape inconsistency between contours and to generate the branching surface. In order to solve these problems, bi-directional smoothing and the composite contour generation method are proposed. Bi-directional smoothing has advantage of removing the shape inconsistency between contours and minimizing shrinkage effect with a large number of iterations. The composite contour by the proposed method ensures smooth transition in branching region.