• Title, Summary, Keyword: finite element simulation

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Evaluation of Probabilistic Finite Element Method in Comparison with Monte Carlo Simulation

  • 이재영;고홍석
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.32 no.E
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    • pp.59-66
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    • 1990
  • Abstract The formulation of the probabilistic finite element method was briefly reviewed. The method was implemented into a computer program for frame analysis which has the same analogy as finite element analysis. Another program for Monte Carlo simulation of finite element analysis was written. Two sample structures were assumed and analized. The characteristics of the second moment statistics obtained by the probabilistic finite element method was examined through numerical studies. The applicability and limitation of the method were also evaluated in comparison with the data generated by Monte Carlo simulation.

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Large Scale Stabilized Finite Element Simulation and Modeling for Environmental Flows in Urban Area

  • Kashiyama Kazuo
    • 한국전산유체공학회:학술대회논문집
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    • pp.21-26
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    • 2006
  • A large-scale finite element simulation and modeling method is presented for environmental flows in urban area. Parallel stabilized finite element method based on domain decomposition method is employed for the numerical simulation. Several GIS and CAD data are used for the preparation of the shape model for landform and urban structures. The present method Is applied to the simulation of flood flow and wind flow In urban area. The present method is shown to be a useful planning and design tool for the natural disasters and the change of environments in urban area.

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

  • Lee, Myeong-Ho
    • Journal of the Korean Society of Marine Engineering
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    • v.33 no.5
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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.

Finite Element Simulation of Axisymmetric Tube Hydroforming Processes (축대칭 튜브 하이드로포밍 공정의 유한요소 시뮬레이션)

  • Kim Y. S.;Keum Y. T.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.58-61
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    • 2001
  • An implicit finite element formulation for axisymmetric tube hydroforming is investigated. In order to describe normal anisotropy of the tube, Hill's non-quadratic yield function is employed. The frictional contact between die and tube and frictionless contact between tube and fluid are considered using the mesh-normal vector computed from finite element mesh of the tube. In order to verify the validity of the developed finite element formulation, the axisymmetric tube bulge test is simulated and simulation results are compared with experimental measurements. In the axisymmetric tube hydroforming process, an optimal hydraulic curve is pursued by performing the simulation with various internal pressures and axial forces.

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Finite Element Simulation of Axisymmetric Sheet Hydroforming Processes (축대칭 박판 액압 성형 공정의 유한요소 시뮬레이션)

  • 구본영;김용석;금영탁
    • Transactions of Materials Processing
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    • v.9 no.6
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    • pp.590-597
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    • 2000
  • A finite element formulation lot the simulation of axisymmetric sheet hydroforming is proposed, and an implicit program is coded. In order to describe normal anisotropy of steel sheet, Hill's non-quadratic yield function (Hill, 1979) is employed. Frictional contacts among sheet surface, rigid tool surface, and flexible hydrostatic pressure are considered using mesh normal vectors based on finite element of the sheet. Applied hydraulic pressure is also considered as a function of forming rate and time and treated as an external loading. The complete set of the governing relations comprising equilibrium and interfacial equations is approximately linearized for Newton-Raphson algorithm. In order to verify the validity of the developed finite element formulation, the axisymmetric bulge test is simulated. Simulation results are compared with other FEM results and experimental measurements and showed good agreements. In axisymmetric hydroforming processes of a disk cover, formability changes are observed according to the hydraulic pressure curve changes.

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Finite Element Simulation of Axisymmeric Tube Hydroforming Processes (축대칭 튜브 하이드로포밍 공정의 유한요소 시뮬레이션)

  • 김용석;금영탁
    • Transactions of Materials Processing
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    • v.11 no.1
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    • pp.75-83
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    • 2002
  • Recently, the hydroforming process is widely applied to the automotive industry and rapidly spreaded to other industries. In this paper, An implicit finite element formulation for simulating axisymmetric tube hydroforming processes is performed. In order to describe normal anisotropy of the tube, Hill's non-quadratic yield function is employed. The frictional contact between die and tube and the frictionless contact between tube and fluid are considered using the mesh-normal vectors computed from the finite element mesh of the tube. The complete set of the governing relations comprising equilibrium and interfacial equations is linearized for Newton-Raphson procedure. In order to verify the validity of the developed finite element formulation, the axisymmetric tube bulge test is simulated and the simulation results are compared with experimental measurements. In a simulation of stepped circular tube hydroforming processes, an optimal hydraulic pressure curve is pursued by considering simultaneously internal pressures and axial forces.

Finite Element Simulation of Elastic Wave Propagation in a Concrete Plate - Modeling and Damage Detection

  • Woo, Jin-Ho;Kim, Jeong-Tae;Cho, Hyun-Man;Na, Won-Bae
    • Journal of Ocean Engineering and Technology
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    • v.21 no.6
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    • pp.26-33
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    • 2007
  • Finite element simulation of elastic wave propagation in a concrete plate was carried out to investigate its modeling and damage detection procedures. For the numerical stability three criteria were introduced and tested. With a proper element size and time increment, two different kinds of damage scenarios (crack and deterioration) were applied to verify the feasibility of the finite element simulation. It is shown that the severities of those damages are sensitive to the received displacement signals.

Finite Element Analysis of Magnetostrictive Linear Actuator (자왜재료를 이용한 선형 작동기의 유한요소 해석)

  • Kim, Yoon-Chang;Kim, Jae-Hwan
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.4
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    • pp.356-362
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    • 2007
  • Magnetostrictive materials have been used for linear actuators due to its large strain, large force output with moderate frequency band in the presence of magnetic field. However their performance analysis is difficult because of nonlinear material behaviors in terms of coupled strain-magnetic field dependence, nonlinear permeability, pre-stress dependence and hysteresis. This paper presents a finite element analysis technique for magnetostrictive linear actuator. To deal with coupled problems and nonlinear behaviors, a simple finite element approach is proposed, which is based on separate magnetic field calculation and displacement simulation. The finite element formulation and an in-house program development are illustrated, and a simulation model is made for a magnetostrictive linear actuator. The fabrication and performance test of the linear actuator are explained, and the performance comparison with simulation result is shown. Since this approach is simple, it can be applied for analyzing magnetostrictive underwater projectors and ultrasonic transducers.

Computer Simulation of Upsetter Forging Processes that uses Finite Volume Method (유한체적법을 이용한 업셋터 단조공정의 컴퓨터 시뮬레이션)

  • Kim, H.T.;Park, S.Y.;Joun, M.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.170-175
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    • 2007
  • The finite volume method for forging simulation is examined to reveal its possibility as well as its problem in this paper. For this study, the finite volume method based MSC/SuperForge and the finite element method based AFDEX are employed. The simulated results of the homogeneous compression obtained by the two softwares are compared to indicate the problems of the finite volume method while several application examples are given to show the possibility of the finite volume method for simulation of upsetter forging processes. It is shown that the finite volume method can not predict the exact solution of the homogeneous compression especially in terms of forming load and deformed shape but that it is helpful to simulate very complex forging processes which can hardly be simulated by the conventional finite element method.

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Finite Element Simulation of Shearing Process Using the Element Kill Method (요소제거법을 이용한 전단가공 공적의 유한요소 시뮬레이션)

  • 고대철;김병민;최재찬
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.229-234
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    • 1994
  • The major objective of the present paper is to estabilish finite element simulation technique in order to further analyze the shearing process. For this the ductile fracture criterion and element kill method are used in the present work. It is postulated that a fracture initiation is based on the magnitude of local effective strain. The features of sheared surface are easily observed by the element kill method. The simulation results are compard with existing experimental results. It is found that the results of the present work are close agreement with the existing results.

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