• 제목/요약/키워드: ALE method

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Finite Element Analysis of Axisymmetric Hot Extrusion Through Continuous Dies Using the Arbitrary Lagrangian-Eulerian Description (곡면금형을 통한 축대창 열간 압출의 ALE 유한요소 해석)

  • 강연식;양동열
    • Transactions of Materials Processing
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    • v.4 no.1
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    • pp.69-78
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    • 1995
  • The arbitrary Lagrangian-Eulerian(ALE) finite element analysis is applied to the axisymmetric hot extrusion through continuous dies. In order to simulate hot forming problems, an ALE scheme for temperature analysis is proposed. The computed results are compared with experimental results as with those by pure Lagrangian method. In the present study mesh control is accomplished by the use of isoparametric mapping of quadrilaterals.

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An ALE Finite Element Formulation for Rigid-Viscoplatic Materials and Its Application to Axisymmetric Extrusion through Square Dies (ALE 묘사에 근거한 강-점소성 유한요소 수식화와 축대칭 평금형 압출에의 적용)

  • 강연식;양동열
    • Transactions of Materials Processing
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    • v.3 no.2
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    • pp.156-166
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    • 1994
  • An arbitrary Lagrangian-Eulerian (ALE) finite element method has been developed. The finite element formation is derived and implemented for rigid-viscoplastic materials. The developed computer program is applied to the analysis of axisymmetric square die extrusion, which has many difficulties with updated Lagrangian approach. The results are compared with those from updated Largrangian approach. The results are compared with those from updated Lagrangian finite element program. Updating scheme of time dependent variables and mesh control are also examined.

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Free Surface Oscillation in Sloshing Problem Predicted with ALE Method

  • Ushijima Satoru
    • 한국전산유체공학회:학술대회논문집
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    • 1999.05a
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    • pp.11-22
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    • 1999
  • A numerical prediction method has been proposed to predict non-linear free surface oscillation in a three-dimensional container. The fluid motions are numerically predicted with Navier-Stokes equations discretized in a Lagrangian scheme with sufficient numerical accuracy. The profile of a free surface is precisely represented with three-dimensional body-fitted coordinates (BFC), which are regenerated in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) formulation. In order to confirm the reliability of the computational method, it was firstly applied to three-dimensional flows within complicated-shaped rigid boundaries, such as curved pipes and ducts. Than it was applied to benchmark computations related to free surface oscillations. Following these basic verifications, non-linear sloshings in a cylindrical tank and transitions from sloshing to swirling motions were numerically predicted. Throughout these computations, the applicability of the present computational method has been confirmed and some of the predicted free surface motions were visualized as sequential images and animations to understand their dynamic futures.

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Cooling Flow Characteristics of an Impinging Liquid Jet Using ALE Finite Element Method (ALE 유한요소법에 의한 충돌 액체 분류 냉각 유동 특성 해석)

  • Sung, Jaeyong;Choi, Hyoung Gwon;Yoo, Jung Yul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.1
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    • pp.43-57
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    • 1999
  • The fluid flow and heat transfer in a thin liquid film are investigated numerically. The flow Is assumed to be two-dimensional laminar and surface tension is considered. The most important characteristics of this flow is the existence of a hydraulic jump through which the flow undergoes very sharp and discontinuous change. Arbitrary Lagrangian-Eulerian(ALE) method is used to describe moving free boundary and a modified SIMPLE algorithm based on streamline upwind Petrov-Galerkin(SUPG) finite element method is used for time marching iterative solution. The numerical results obtained by solving unsteady full Navier-Stokes equations are presented for planar and radial flows subject to constant wall temperature or constant wall heat flux, and compared with available experimental data. It Is discussed systematically how the inlet Reynolds and Froude numbers and surface tension affect the formation of a hydraulic jump. In particular, the effect of temperature dependent fluid properties is also discussed.

Applicability Analysis of the FE Analysis Method Based on the Empirical Equation for Near-field Explosions (근거리 폭발에 대한 경험식 기반 유한요소해석 방법의 적용성 분석)

  • Hyun-Seop, Shin;Sung-Wook, Kim;Jae-Heum, Moon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.6
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    • pp.333-342
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    • 2022
  • The blast analysis method entails the use of an empirical equation and application of the pressure-time history curve as an explosive load. Although this method is efficient owing to its simple model and short run time, previous studies indicate that it may not be appropriate for near-field explosions. In this study, we investigated why different results were observed for the analysis method by considering an RC beam under near-field explosion conditions with the scaled distance of 0.4-1.0 as an example. On this basis, we examined the application range of the empirical analysis method by using the finite element analysis program LS-DYNA. The results indicate that the empirical analysis method based on data from far-field explosion tests underestimates the impulse. Thus, the calculated deflection of the RC beam would be smaller than the measured deflection and arbitrary Lagrangian-Eulerian (ALE) analysis result. The ALE analysis method is more suitable for near-field explosion conditions wherein the structural responses are large.

Transient Response Analysis of Cylindrical Liquid Fuel-Storage Tank subject to Initial Acceleration (원통형 액체 연료탱크의 초기 가속에 따른 과도응답 해석)

  • Lee, S.Y.;Joo, Y.S.;Kim, K.W.;Cho, J.R.
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.475-480
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    • 2000
  • The transient dynamic-response analysis of fuel-storage tanks of flying vehicles accelerating in the vertical direction is achieved with finite element method. A fuel-storage tank is a representative example of the fluid-structure interaction problem, in which structure and fluid media interact strongly. For the accurate analysis of this complicated fluid-structure system, we employed ALE(arbitrary Lagrangian-Eulerian) coupling method. Two types of fuel-storage tanks, one with two baffles and the other without baffle, are considered to examine the effect of baffles. The fuel-storage tank with baffles shows more uniform hydrodynamic pressure distribution, resulting effective stress in structural region and faster convergence from transient to steady states. MSC/Dytran, a commercial FEM software for the 3D coupled dynamic analysis, is used for this analysis.

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FE Analysis of Three Dimensional Backward Extrusion Using the ALE description (ALE 묘사에 왜한 3차원 후방압출 해석)

  • 정상원;정용호;김규하;조규종
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.628-631
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    • 2002
  • This paper has executed FE-analysis to review the feasibility for developing the process, which produces the narrow-cubic type cans, using the Backward Impact Extrusion process instead of using current process, multi-stage deep drawing. Proposes an analysis method by applying ALE(Arbitrary Lagrangian-Eulerian) description to non-axisymmetric extrusion. which is appreciated as one of good solution to mesh distortion in case of the large deformation plasticity process that has mass flux, and considers the factors which affects forming-loads related to punch velocity and fulid status of material.

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Noise Cancellation and Detection of Heartbeat using A New Adaptive Noise Canceller Based on ALE(Adaptive Line Enhancer) in the CW Bio-radar (CW 바이오 레이더에서 ALE(Adaptive Line Enhancer) 기반의 새로운 적응형 잡음제거기를 이용한 잡음제거 및 심장박동 검출)

  • Seo, Myung-Hwan;Kim, Jae-Joong
    • Journal of Advanced Navigation Technology
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    • v.13 no.4
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    • pp.482-489
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    • 2009
  • This paper proposes a CW(Continuous-Wave) bio-radar applying a new adaptive noise canceller based on ALE(Adaptive Line Enhancer) which can remove the Gaussian noise and system noise. Recently the research works on this CW bio-radar which can be used to detect heartbeat and respiration are advanced by the university and research facility. Although the researches describe CW bio-radar not only is vulnerable for the Gaussian noise but also has a disadvantage of decreasing the heart-rate accuracy due to the noise, the researches do not demonstrate the effective method for removing the noise component in a baseband signal. In this paper, a CW bio-radar applying the new adaptive noise canceller based on ALE which can remove the noise component is proposed. This paper compares and analyzes the performance for increasing the heart-rate accuracy according to removing the Gaussian noise and system noise in the baseband signal through the quadrature receiver which can alleviate the demodulation sensitivity to target position.

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Effects of Auklandia Lappa on Dextran Sulfate Sodium-Induced Murine Colitis (당목향(唐木香)이 DSS(Dextran sulfate sodium)로 유발된 염증성 장질환 동물모델에 미치는 영향)

  • Kim, So-Yeon;Park, Jae-Woo;Ryu, Bong-Ha
    • The Journal of Internal Korean Medicine
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    • v.34 no.2
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    • pp.134-146
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    • 2013
  • Objectives : Auklandia Lappa (ALE) is one of the herbs used frequently to treat abdominal pain and diarrhea and reported anti-inflammatory activity by suppressing proinflammatory cytokines. This study was designed to investigate whether ALE could show protective activities on experimental colitis induced by dextran sulfate sodium (DSS) models. Methods : Colitis was induced by DSS in Balb/c mice. ALE 10, 30, 100 and 300 mg/kg were orally administered twice a day for 7 days in DSS model. Mice weight was measured daily. Scoring of clinical findings was measured every other day. Colon length, edema, fecal blood and histological damages were assessed at day 7 in DSS model. In histological analysis, we checked cryptal glands, surface epithelium, submucosa, transmural, stroma and scored degree of inflammatory cell damage by modified histological scoring. We also calculated cytokines concentrations including IFN-${\gamma}$, TNF-${\alpha}$, IL-6, IL-$1{\beta}$, IL-17, IL-23, IL-10 and TGF-${\beta}1$ by Biometric Multiplex Cytokine Profiling method. Results : ALE showed the protective effects on DSS-induced experimental colitis. ALE inhibited shortening of colon length and histological damages of colon does-dependently, but it did not inhibit weight loss. ALE also inhibited IFN-${\gamma}$ and IL-6 expression, and upregulated cytokines (IL-10, TGF-${\beta}1$) related to regulatory T cell differentiation and proliferation. Conclusions : The current results demonstrate the clinical utility of ALE in traditional medicine and indicate the possibility of potent drug development of inflammatory bowel diseases from natural products. Further investigations for exact mechanisms will be needed.

A method for automatic EPC code conversion based on ontology methodology (온톨로지 기반 EPC 코드 자동 변환 방법)

  • Noh, Young-Sik;Byun, Yung-Cheol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.3
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    • pp.452-460
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    • 2008
  • ALE-complient RFID middleware system receives EPC code data from reader devices and converts the data into URN format data internally. After filtering and grouping, the system sends the resulting URN code to application and(or) users. Meanwhile, not only the types of EPC code are very diverse, but also another new kinds of EPC code can be emerged in the future. Therefore, a method to process all kinds of EPC code effectively is required by RFID middleware. In this paper, a method to process various kinds of EPC code acquired from RFID reader devices in ALE-complient RFID middleware is proposed. Especially, we propose an approach using ontology technology to process not only existing EPC code but also newly defined code in the future. That is, we build an ontology of conversion rules for each EPC data type to effectively convert EPC data into URL format data. In this case, we can easily extend RFID middleware to process a new EPC code data by adding a conversion rule ontology for the code.