• Title/Summary/Keyword: ALE(arbitrary Lagrangian-Eulerian)

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Evaluation of Pullout Capacity of Embedded Suction Anchors in Uniform Clay using Numerical Analysis with ALE(Arbitrary Lagrangian Eulerian) Technique (ALE 기법이 적용된 수치해석을 통한 점토지반에서 석션 매입 앵커의 인발 저항력 평가)

  • Na, SeonHong;Jang, In-Sung;Kwon, OSoon;Lee, Seung-Hyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2428-2435
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    • 2014
  • Numerical analysis with ALE (Arbitrary Lagrangian Eulerian) Adaptive Meshing technique was performed to evaluate the pullout capacity of the embedded suction anchors (ESA) in uniform clay. The numerical method was verified by the previous study, analytical results based on limit-equilibrium theory and centrifuge tests. The pullout capacity of the ESA under horizontal, vertical, and inclined loading were evaluated, and the effect of initial rotation of the ESA on pullout capacity was also investigated. The analysis results showed that the maximum horizontal capacity was obtained at the mid-point, and the each vertical capacity gave the similar value regardless of the loading points. Furthermore, the inclined capacity was decreased as the load inclination angle increased at the mid-point of the anchor, and almost the same pullout capacity was obtained when the initial rotation angles were below 30 degrees.

Simulation of dynamic fracture and fluid-structure interaction in solid propellant rockets : Part 1 (theoretical aspects) (고체추진로켓 내부에서 발생하는 동적 파괴 현상과 유체-고체 상호작용의 시뮬레이션 - Part 1 (이론적 측면))

  • Hwang, Chan-Gyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.2
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    • pp.286-290
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    • 2008
  • This paper summarizes the components of an explicit aeroelastic solver developed especially for the simulation of dynamic fracture events occurring during the flight of solid propellant rockets. The numerical method combines an explicit Arbitrary Lagrangian Eulerian (ALE) version of the Cohesive Volumetric Finite Element (CVFE) scheme, used to simulate the spontaneous motion of one or more cracks propagating dynamically through a domain with regressing boundaries, and an explicit unstructured finite volume Euler code to follow the flow field during the failure event. A key feature of the algorithm is the ability to adaptively repair and expand the fluid mesh to handle the large geometrical changes associated with grain deformation and crack motion.

ALE-Based FSI Simulation of Solid Propellant Rocket Interior (ALE 기반의 고체 로켓 내부 유체-구조 연계 해석)

  • Han, Sang-Ho;Choi, H.S.;Min, D.H.;Kim, C.;Hwang, Chan-Gyu
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.510-513
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    • 2008
  • The traditional computational fluid or structure dynamics analysis approaches have contributed to solve many delicate engineering problems. But for the most of recent engineering problems which are influenced by fluid-structure interaction effect strongly, traditional individual approaches have limited analysis abilities for the exact simulation. Owing to above-mentioned reason, nowadays fluid-structure interaction analysis has become a matter of concern and interest. FSI analysis require several unprecedented techniques for the combining individual analysis tool into integrated analysis tool. The Arbitrary Lagrangian-Eulerian(ALE, in short) method is the new description of continum motion,which combines the advantages of the classical kinematical descriptions, i.e. Lagrangian and Eulerian description, while minimizing their respective drawbacks. In this paper, the ALE description is adapted to simulate fluid-structure interaction problems. An automatic re-mesh algorithm and a fluid-structure coupling process are included to analyze the interaction and moving motion during the 2-D axisymmetric solid rocket interior FSI phenomena simulation.

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A Three-Dimensional Rigid-Viscoplastic Finite Element Analysis of isothermal Square Die Extrusion of a Square Section Based on ALE Description (강-점소성 ALE 유한요소 수식화에 근거한 사각형 형재의 평금형 등온 압출에 대한 3차원 해석)

  • 강연식;양동열
    • Transactions of Materials Processing
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    • v.5 no.1
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    • pp.55-60
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    • 1996
  • In the finite element analysis of metal forming processes the updated Lagrangian approach has been widely and effectively used to simulate the non-steady state problems. however some difficulties have arisen from abrupt flow change as in extrusion through square dies. In the present work an ALE(arbitrary Lagrangian-Euleria) finite element formulation for deforma-tion analysis are presented fro rigid-viscoplastic materials. The developed finite element program is applied to the isothermal analysis of square die extrusion of a square section. The computational results are compared with those by the updated Lagrangian finite element analysis.

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Shock Response Analysis under Underwater Explosion for Underwater Ship using ALE Technique (ALE기법을 이용한 수중함의 수중폭발 충격응답 해석에 관한 연구)

  • Kim, Jae-Hyun
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.10 no.4
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    • pp.218-226
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    • 2007
  • In modern naval ships, the design of submarines has continually evolved to improve survivability and it is also important to design ship against shock response. Exiting underwater ship design has been peformed due to results of static analysis considering shock acceleration by simple method. However, it can not be anticipated good assesment. The present study applied the Arbitrary Lagrangian-Eulerian (ALE) technique, a fluid-structure interaction approach, to simulate an underwater explosion and investigate the survival capability of a damaged submarine liquefied oxygen tank. The Lagrangian-Eulerian coupling algorithm and the equations of state for explosives and seawater were also reviewed. It is shown that underwater explosion analysis using the ALE technique can accurately evaluate structural damage after attack. This procedure could be applied quantitatively to real structural design.

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Optimal Mesh Size in Three-Dimensional Arbitrary Lagrangian-Eulerian Method of Free-air Explosions (3차원 Arbitrary Lagrangian-Eulerian 기법을 사용한 자유 대기 중 폭발 해석의 최적 격자망 크기 산정)

  • Yena Lee;Tae Hee Lee;Dawon Park;Youngjun Choi;Jung-Wuk Hong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.6
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    • pp.355-364
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    • 2023
  • The arbitrary Lagrangian-Eulerian (ALE) method has been extensively researched owing to its capability to accurately predict the propagation of blast shock waves. Although the use of the ALE method for dynamic analysis can produce unreliable results depending on the mesh size of the finite element, few studies have explored the relationship between the mesh size for the air domain and the accuracy of numerical analysis. In this study, we propose a procedure to calculate the optimal mesh size based on the mean squared error between the maximum blast pressure values obtained from numerical simulations and experiments. Furthermore, we analyze the relationship between the weight of explosive material (TNT) and the optimal mesh size of the air domain. The findings from this study can contribute to estimating the optimal mesh size in blast simulations with various explosion weights and promote the development of advanced blast numerical analysis models.

Study on Pullout Behavior of Embedded Suction Anchors in Sand using ALE (Arbitrary Lagrangian Eulerian) Technique (ALE 기법을 이용한 모래지반에서 석션 매입 앵커의 인발 거동 분석)

  • Na, Seon Hong;Jang, In Sung;Kwon, O Soon;Lee, Seung Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.1
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    • pp.167-173
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    • 2014
  • The embedded suction anchor, ESA, is one type of mooring anchor systems which utilizes the suction pile or caisson to penetrate the anchor into the sea bed and develops its capacity under pullout load. In this study, the numerical analysis using ALE (Arbitrary Lagrangian Eulerian) Adaptive Meshing technique was performed to simulate the pullout behavior of the ESA, and the results were compared to those of the previous research, centrifuge model tests and the analytical method based on limit equilibrium theory. The pullout behaviors of the ESA under horizontal, vertical, and inclined loading were evaluated. The analysis results showed that the maximum horizontal pullout load was developed when the location of loading point was at the mid-point, and the each vertical pullout load gave the similar value regardless of the locations of the loading points. The pullout load decreased as the load inclination angle increased at the mid-point of the anchor.

The Spectrally Accurate Method Applied to Wave-Current Interaction as a Freak Wave Generation Mechanism

  • Sung, Hong-Gun;Hong, Key-Yong;Kyoung, Jo-Hyun;Hong, Sa-Young
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.113-120
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    • 2006
  • In this paper, generation mechanisms of ocean freak waves are briefly introduced in the context of wave-current interaction phenomena. As an accurate and efficient numerical tool, the spectral element method is presented with general features and specific treatment for the wave-current interaction problem. The present model of the fluid motion is based on the Navier-Stokes equations incorporating a velocity-pressure formulation. In order to deal with the free surface motion, an Arbitrary Lagrangian-Eulerian (ALE) description is adopted. As an intermediate stage of development, solution procedure and characteristic aspects of the present modeling and numerical method features are addressed in detail, and numerical results for wave-current interaction is left as further study.

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Numerical Analysis for the Piston-Driven Intake Flows using the Finite Element Method (피스톤에 의해 유입되는 유동에 대한 유한요소법을 이용한 수치해석)

  • Choi J. W.;Park C. K.
    • Journal of computational fluids engineering
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    • v.4 no.2
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    • pp.39-46
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    • 1999
  • The FVM(Finite Volume Method) have been used mainly for the flow analyses in the piston-cylinder. The objective of the present study is to analyze numerically the piston-driven intake flows using the FEM(Finite Element Method). The FEM algorithm used in this study is 4-step time-splitting method which requires much less execution time and computer storage than the velocity-pressure integrated method and the penalty method. And the explicit Lax-Wendroff scheme is applied to nonlinear convective term in the momentum equations to prevent checkerboard pressure oscillations. Also, the ALE(arbitrary Lagrangian Eulerian) method is adopted for the moving grids. The calculated results show good agreement in comparison with those by the FVM and the experimental results by the LDA.

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Evaluation of sloshing Resistance Performance of LNG Carrier Insulation System by Fluid-Structure Interaction Analysis (유체-구조 연성 해석을 이용한 LNG 운반선 방열시스템의 내슬로싱 성능 평가)

  • Lee, Chi-Seung;Kim, Joo-Hyun;Kim, Wha-Soo;Noh, Byeong-Jae;Kim, Myung-Hyun;Lee, Jae-Myung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2011.04a
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    • pp.557-560
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    • 2011
  • In the present paper, the sloshing resistance performance of an LNG carrier insulation system is evaluated by fluid-structure interaction (FSI) analysis. For this analysis, the arbitrary Lagrangian Eulerian (ALE) method is adopted to accurately calculate the structural behavior induced by internal LNG motion of a KC-1 type LNG carrier cargo tank. In addition, the global-local analysis method is introduced to reduce computational time and cost. The global model is built from shell elements to reduce the sloshing analysis time. The proposed novel analysis techniques can potentially be used to evaluate the structural integrity of LNG carrier insulation systems.

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