• Title/Summary/Keyword: finite 1-type

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Finite Element Analysis of Silo Type Underground Opening for LILW Disposal Facility (사일로 구조형식 중저준위 방폐물 처분동굴의 유한요소 해석)

  • Kim, Sun-Hoon;Kim, Kwang-Jin
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.5
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    • pp.339-345
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    • 2021
  • Finite element analysis of the silo type underground opening for low- and intermediate-level radioactive waste (LILW) disposal facilities in Korea is presented in this study. The silo wall is circular and the roof is made up of domes. The silo wall is 25 meters in diameter, 35 meters in height, and the dome is 30 meters in diameter and 17.4 meters in height, and it is located at -80 meters to -130 meters at sea level. Although six silos have been constructed in the first stage and are in operation, only one silo was considered in this study. The two-dimensional axial symmetric finite element model, as well as the three-dimensional finite element model were made using the computer program SMAP-3D. Generalized Hoek and Brown Model was used for the numerical analyses. The finite element analysis of the silo type underground opening was carried out under various lateral pressure coefficients (defined as ratio of average horizontal to vertical in-situ stress), and the numerical results of these analyses were examined.

Preconditioning Method of a Finite Element Combined Formulation for Fluid-Structure Interaction (유체-구조물 상호작용을 위한 유한요소 결합공식화의 예조건화에 대한 연구)

  • Choi, Hyoung-Gwon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.4
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    • pp.242-247
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    • 2009
  • AILU type preconditioners for a two-dimensional combined P2P1 finite element formulation of the interaction of rigid cylinder with incompressible fluid flow have been devised and tested by solving fluid-structure interaction (FSI) problems. The FSI code simulating the interaction of a rigid cylinder with an unsteady flow is based on P2P1 mixed finite element formulation coupled with combined formulation. Four different preconditioners were devised for the two-dimensional combined P2P1 finite element formulation extending the idea of Nam et al., which was proposed for the preconditioning of a P2P1 mixed finite element formulation of the incompressible Navier-Stokes equations. It was found that PC-III or PC-IV among them perform well with respect to computational memory and convergence rate for some bench-mark problems.

Vectorization of an Explicit Finite Element Method on Memory-to-Memory Type Vector Computer (Memory-to-Memory방식 벡터컴퓨터에서의 외연적 유한요소법의 벡터화)

  • 이지호;이재석
    • Computational Structural Engineering
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    • v.4 no.1
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    • pp.95-108
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    • 1991
  • An explicit finite element method can be executed more rapidly and effectively on vector computer than on the scalar computer because it has suitable structures for vector processing. In this paper, an efficient vectorization method of the explicit finite element program on the memory-to-memory type vector computer is proposed. First, the general vectorization method which can be applied regardless of the vector architecture is investigated, then the method which is suitable for the memory-to-memory type vector computer is proposed. To illustrate the usefulness of the proposed vectorization method, DYNA3D, the existing explicit finite element program, is migrated on HDS AS/XL V50 which is the memory-to-memory type vector computer. Performance results on actual test show a vector/scalar speedup is above 2.4.

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Geometrically Nonlinear Analysis of Plates Subjected to Uniaxial Compression by Finite Strip Method (일축(一軸) 압축(壓縮)을 받는 판(板)의 유한대판법(有限帶板法)에 의한 기하학적(幾何學的) 비선형(非線型) 해석(解析))

  • Lee, Yong Jae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.3
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    • pp.107-115
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    • 1985
  • For the finite deflection analysis of plates with initial deflections subjected to uniaxial compression, the formulation of incremental finite strip method is made and has been incorporated into a computer program. A new in plane displacement function varying along the load: direction has been derived from the out-of-plane displacement function by considering the curvature of a plate. Either incremental load type analysis or incremental displacement type analysis may be selected to solve incremental equibrium equations in the program. The following results have been obtained: 1. Incremental displacement type analysis is superior to incremental load type analysis in that the former converges more rapidly than the latter. 2. The finite strip method using the new displacement function gives as accurate results as analytical method and other finite element methods.

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Modified Design of Floating Type Photovoltaic Energy Generation System (부유식 태양광 에너지 발전시설의 수정설계)

  • Lee, Young-Geun;Joo, Hyung-Joong;Nam, Jeong-Hun;Yoon, Soon-Jong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.1 no.4
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    • pp.18-27
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    • 2010
  • We had designed and constructed floating type photovoltaic energy generation system. In this paper, we present the result of investigations pertaining to the development of links between unit modules of the floating type photovoltaic energy generation system. The link system installed between the unit modules is made of pultruded FRP, tire, and polyethilene synthetic fiber rope. The link system is analized by the finite element method. The floating type photovoltaic energy generation system consisted of unit modules connected by link system is installed successfully at sea site. In addition, we present the modified design of the floating type photovoltaic energy generation system based on the proto type system.

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Comparing Two Approaches of Analyzing Mixed Finite Volume Methods

  • Chou, So-Hsiang;Tang, Shengrong
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.5 no.1
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    • pp.55-78
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    • 2001
  • Given the anisotropic Poisson equation $-{\nabla}{\cdot}{\mathcal{K}}{\nabla}p=f$, one can convert it into a system of two first order PDEs: the Darcy law for the flux $u=-{\mathcal{K}{\nabla}p$ and conservation of mass ${\nabla}{\cdot}u=f$. A very natural mixed finite volume method for this system is to seek the pressure in the nonconforming P1 space and the Darcy velocity in the lowest order Raviart-Thomas space. The equations for these variables are obtained by integrating the two first order systems over the triangular volumes. In this paper we show that such a method is really a standard finite element method with local recovery of the flux in disguise. As a consequence, we compare two approaches in analyzing finite volume methods (FVM) and shed light on the proper way of analyzing non co-volume type of FVM. Numerical results for Dirichlet and Neumann problems are included.

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SHAPE OPERATOR AND GAUSS MAP OF POINTWISE 1-TYPE

  • KIM, DONG-SOO;KIM, YOUNG HO
    • Journal of the Korean Mathematical Society
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    • v.52 no.6
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    • pp.1337-1346
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    • 2015
  • We examine the relationship of the shape operator of a surface of Euclidean 3-space with its Gauss map of pointwise 1-type. Surfaces with constant mean curvature and right circular cones with respect to some properties of the shape operator are characterized when their Gauss map is of pointwise 1-type.

Numerical Analysis of Shock-Wave Focusing from a Two-Dimensional Parabolic Reflector (2차원 포물형 반사경에 의한 충격파의 촛점형성에 대한 수치해석)

  • 최환석;백제현
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.3
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    • pp.612-623
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    • 1994
  • Shock-wave focusing from a two-dimensional parabolic reflector was simulated using an explicit finite volume upwind TVD scheme. Computations were performed for three different incident shock speeds of $M_s$ = 1.1, 1.2 and 1.3, corresponding to the relatively weak, intermediate, and strong shock waves, respectively. Numerical solutions nicely resolved all the waves evolving through the focusing process. As the incident shock strength increase, a transition was observed in the shock-fronts geometry that was caused by the change in the reflection type of converging shock fronts on the axis of symmetry, from regular-type to Mach-type reflection. The computed maximum on-axis pressure amplification and the trajectories of three-wave intersections showed good agreement with experimental results. The strong nonlinear effect near the focal region which determines the shock-fronts geometries at and behind the focus and at the same time confines the pressure amplification at the focus was clearly revealed from the present numerical simulation.

An Optimum Design of Flat-type $L_{1}-B){8}$ Mode Ultrasonic Motors Using FEM Simulation (유한요소해석 시뮬레이션을 이용한 평판형 $L_{1}-B){8}$ 모드 초음파 전동기의 최적 설계)

  • 우상호;김우태;신순인;김진수;사정우;김기수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.664-667
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    • 2001
  • A flat-type L$_1$-B$_{8}$ Mode Ultrasonic motor(USM) uses longitudinal-bending multi-mode vibrator which is constructed with the metal-piezoceramic composite thin plate vibrator. Especially, the characteristics of vibrating displacement of the vibrator are important for the fabrication of USM. So, in this study, we tried to analyze them by the FEM(finite element method) simulation program. ANSYS 5.6 we used is a finite element software enabling the analysis of 2 or 3 dimensional structure of piezoelectric materials. Using this made us analyzing the resonance frequency and calculating displacement of vibrator and then the position of the projection.n.

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