• Title/Summary/Keyword: FEM(Finite element method)

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고받음각에서 기동하는 미사일의 공력-구조 연계 해석 (FLUID-STRUCTURE INTERACTION ANALYSIS FOR HIGH ANGLE OF ATTACK MANEUVER MISSILE)

  • 노경호;박미영;박수형;이재우;변영환
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2007년도 추계 학술대회논문집
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    • pp.111-114
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    • 2007
  • Computational Fluid Dynamics (CFD) and the Finite Element Method (FEM) are used to perform aerodynamics analysis and structure analysis. For the fluid-structure interaction analysis, each technology should be considered as well. The process of aerodynamics-structure coupled analysis can be applied to various integrated analyses from many research fields. In this study, the aerodynamics-structure coupled analysis is performed for the missile at high angle of attack condition through the use of Computational Fluid Dynamics (CFD) and the Finite Element Method (FEM). For this purpose, the aerodynamics-structure coupled analyses procedure for the missile are established. The results of the integrated analysis are compared with rigid geometry of the missile and the effect of the deformation will be addressed.

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노치응력접근법을 이용한 차량구조재 용접이음부의 피로내구성 해석 (Analysis of Fatigue Durability on Seam Weldment using Notch Stress Approach)

  • 김민건;민태국
    • Journal of Welding and Joining
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    • 제22권2호
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    • pp.28-32
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    • 2004
  • Fatigue life at seam weldment of thick plate was estimated using the finite element and FEM-FAT(an exclusive fatigue solver). Finite element meshing at toe and root of weldment was based oil Radaj's theory. Also, the results of FE analysis were compared with experimental results in the point of Miner's Rule. The results of FE and FEM-FAT analysis were in accord with experimental results within 60% confidence. This result reveals that above techniques is useful in assessment of seam weldment and to be an alternative method instead of an object experiment.

Numerical study on concrete penetration/perforation under high velocity impact by ogive-nose steel projectile

  • Islam, Md. Jahidul;Liu, Zishun;Swaddiwudhipong, Somsak
    • Computers and Concrete
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    • 제8권1호
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    • pp.111-123
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    • 2011
  • Severe element distortion problem is observed in finite element mesh while performing numerical simulations of high velocity steel projectiles penetration/perforation of concrete targets using finite element method (FEM). This problem of element distortion in Lagrangian formulation of FEM can be resolved by using element erosion methodology. Element erosion approach is applied in the finite element program by defining failure parameters as a condition for element elimination. In this study strain parameters for both compression and tension at failure are used as failure criteria. Since no direct method exists to determine these values, a calibration approach is used to establish suitable failure strain values while performing numerical simulations of ogive-nose steel projectile penetration/perforation into concrete target. A range of erosion parameters is suggested and adopted in concrete penetration/perforation tests to validate the suggested values. Good agreement between the numerical and field data is observed.

적응적 세분화기법을 이용한 효율적 무요소법에 관한 연구 (A Study on the Efficient Meshfree Method Using Adaptive Refinement Analysis)

  • 한규택
    • 한국기계가공학회지
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    • 제9권5호
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    • pp.50-56
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    • 2010
  • Meshfree methods show many advantages over finite element method(FEM) in the class of problems for which the remeshing process is inevitable when the conventional FEM used, such as propagating crack problems, large deformation and so on. One of the promising applications of meshfree methods is the adaptive refinement for problems having multi-scale nature. In this study, an adaptive node generation procedure is proposed and several numerical examples are also presented to illustrate the efficiency of proposed method.

진동 벽면을 가진 단순 확장형 소음기 모델의 투과손실 특성 해석을 위한 DIRECT BEM-FEM 연성 모델의 적용 (The Application of a Direct Coupled BEM-FEM Model to Predict the TL Characteristics of Simple Expansion Silencers with Vibratory Walls)

  • 최창환;김호용
    • 한국자동차공학회논문집
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    • 제6권6호
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    • pp.24-30
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    • 1998
  • A directly coupled Boundary Element and Finite Element Model was applied to the dynamic analysis of a coupled acoustic silencer with vibratory wall. In this cupled BEM-FEM muffler model, the BEM model was used to discretize the acoustic cavity and the FEM model was used to discretize the vibratory wall structure. Then the BEM model was coupled with the FEM model. The results of the coupled BEM-FEM model for the dynamic analysis of the simple expansion type reactive muffler configurations with flexible walls were verified by comparing the predicted results to analytical solutions. In order to investigate the effects of the muffler's structural flexibility on its transmission loss(TL) characteristics, the results of the coupled BEM-FEM model in conjunction with the four-pole parameter theory were utilized. The muffler's TL characteristics using the BEM-FEM coupled model with flexible walls as compared to other muffler configurations was studied. Finally the muffler's TL values with respect to different wall's thickness are predicted and compared.

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Isogeometric analysis of the seismic response of a gravity dam: A comparison with FEM

  • Abdelhafid Lahdiri;Mohammed Kadri
    • Advances in Computational Design
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    • 제9권2호
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    • pp.81-96
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    • 2024
  • Modeling and analyzing the dynamic behavior of fluid-soil-structure interaction problems are crucial in structural engineering. The solution to such coupled engineering systems is often not achievable through analytical modeling alone, and a numerical solution is necessary. Generally, the Finite Element Method (FEM) is commonly used to address such problems. However, when dealing with coupled problems with complex geometry, the finite element method may not precisely represent the geometry, leading to errors that impact solution quality. Recently, Isogeometric Analysis (IGA) has emerged as a preferred method for modeling and analyzing complex systems. In this study, IGA based on Non-Uniform Rational B-Splines (NURBS) is employed to analyze the seismic behavior of concrete gravity dams, considering fluid-structure-foundation interaction. The performance of IGA is then compared with the classical finite element solution. The computational efficiency of IGA is demonstrated through case studies involving simulations of the reservoir-foundation-dam system under seismic loading.

유한요소 LES법에 의한 축류 회전차 팁 틈새의 유동해석 (Flow Analysis in the Tip Clearance of Axial Flow Rotor Using Finite-Element Large-Eddy Simulation Method)

  • 이명호
    • Journal of Advanced Marine Engineering and Technology
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    • 제33권5호
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    • pp.686-695
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    • 2009
  • Flow characteristics in linear axial cascade have been studied using large eddy simulation(LES) based on finite element method(FEM) to investigate details of the leakage flow in the tip clearance of axial flow rotor. STAR-CD(FVM) and PAT-Flow(FEM) have been adopted to solve the Navier-Stokes equations for the simulation of the unsteady turbulent flow. Numerical results from the present study have been compared with the existing experimental results to investigate a tip clearance effect on velocity profile and static pressure distribution on blade surface at various spanwise positions. Both simulation results agree well with the experimental data. However, it has been shown that the results of finite-element large-eddy simulation agree better with experimental data than $k-{\varepsilon}$ turbulent model based on finite volume method regarding the tip vortex geometry and static pressure distribution at the center of the tip vortex core. As a result of this study, it is shown that finite-element large-eddy simulation method can predict more exactly on the tip leakage vortex flow and behind flow field.

FEM 시뮬레이션을 이용한 tonpilz 트랜스듀서의 먼지 응집 거동 (FEM simulation on dust-collecting performance of tonpilz transducer using finite element method)

  • 서진원;최균;이호용
    • 한국결정성장학회지
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    • 제26권6호
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    • pp.252-257
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    • 2016
  • Tonpilz 트랜스듀서를 이용한 미세먼지의 포집 거동을 살펴보기 위하여 유한요소법(FEM) 시뮬레이션을 이용하여 미세먼지의 응집 거동을 모사하였다. 원판형 head mass의 두께와 tail mass의 직경, 그리고 고정 볼트의 깊이를 트랜스듀서의 형상 변수로 고려하였다. 도넛형 압전체의 소재로는 기존의 PZT-4 소재와 서로 다른 특성의 두 가지 압전 단결정에 대하여 그 출력에 미치는 형상 변수의 최적화를 구현하였고 이를 통하여 얻은 트랜스듀서를 이용하였을 때 나타나는 미세먼지의 응집 거동을 다중 물리해석 S/W인 COMSOL을 이용하여 모사하였다.

강도 감소법에 의한 지하수위를 고려한 FEM 사면안정해석 (Slope Stability Analysis Considering Seepage Conditions by FEM Using Strength Reduction Technique)

  • 김영민
    • 한국지반공학회논문집
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    • 제20권8호
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    • pp.97-102
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    • 2004
  • 본 논문은 기존의 한계 평형법 보다 사면의 파괴거동을 잘 묘사할 수 있는 유한요소법에 의한 사면의 안전율을 결정하는 방법에 대하여 기술하였다. 특히, 지하수위를 고려하는 사면의 파괴거동을 강도감소법에 의한 유한요소법으로 산정하였다. 그 결과, 강도 감소법을 이용한 FEM해석방법이 사면의 안정해석에 대하여 파괴거동과 안전율을 구하는데 유효한 수단임을 보여 주었다. 그리고 지하수 상승경우와 지하수 급강하 사면의 경우에 대하여 자세히 분석하였으며, 한계평형법인 Bishop간편법 해석결과와 비교, 검토하였다.

FEM과 BEM을 사용한 소리굽쇠 분석 (Tuning Fork Analysis using FEM and BEM)

  • Jarng, Soon-Suck;Lee, Je-Hyeong;Park, Yeun-Young
    • 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)

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