• Title/Summary/Keyword: element size

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One-Ampere Conductor Method for Tubular Linear Induction Motor for Size Reduction of Primary Iron Core

  • Lee, Byeong-Hwa;Kim, Kyu-Seob;Kwon, Soon-O;Sun, Tao;Hong, Jung-Pyo;Lee, Jung-Ho
    • Journal of Magnetics
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    • v.16 no.1
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    • pp.46-50
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    • 2011
  • This paper presents size reduction of primary iron core for tubular linear induction motor by improved winding configuration. Using one-ampere conductor method, magnetic field analysis of tubular linear induction motor for size reduction is conducted. Size reduction and improvement of air gap flux distribution is achieved by improved winding configuration, and analysis results are verified by finite element analysis (FEA) and experiments.

Nonlinear finite element analysis on the pullout behavior of the mechanical anchorage of reinforcement in concrete (기계적 정착된 철근의 인발거동에 대한 비선형 유한요소 해석)

  • 천성철;이성호;오보환;박형철;나환선;김상구
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.132-135
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    • 2003
  • Mechanical anchorage can substitute a standard hook. To enhance the workability and economical benefit of mechanical anchorage, the size of anchor plate should be optimized. In this paper, the pull-out behaviors such as strength, failure mode, and crack patterns of mechanically anchored reinforcement in concrete are investigated using nonlinear finite element analysis. The nonlinear finite element analysis results are consistent with the experimental results. These results show that the optimal anchor plates can be designed using the nonlinear finite element analysis.

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On boundary discretization and integration in frequency-domain boundary element method

  • Fu, Tia Ming;Nogami, Toyoaki
    • Structural Engineering and Mechanics
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    • v.6 no.3
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    • pp.339-345
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    • 1998
  • The computation size and accuracy in the boundary element method are mutually coupled and strongly influenced by the formulations in boundary discretization and integration. This aspect is studied numerically for two-dimensional elastodynamic problems in the frequency-domain. The localized nature of error is observed in the computed results. A boundary discretization criterion is examined. The number of integration points in the boundary integration is studied to find the optimum number for accuracy. Useful information is obtained concerning the optimization in boundary discretization and integration.

On the Numerical Procedure for Estimating Structural Stress of Welded Structures (수치해석을 통한 용접구조물의 구조응력 추정에 관한 연구)

  • Kang, Sung-Won;Kim, Myung-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.4 s.142
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    • pp.388-395
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    • 2005
  • A numerical procedure is proposed as a mesh-size insensitive structural stress definition that gives a stress state at a weld toe with relatively large mesh size. The structural stress values obtained using different finite element types, i.e. shell element and solid element, are examined for typical weld structures. The calculation procedures are performed using the balanced nodal forces and moments obtained from finite element solutions. A consistent formulation based on work equivalent argument has been implemented to transform the balanced nodal forces and moments from shell to line force and line moments at each nodal position. The mesh-insensitivity, the effect of distance $\delta$(where the stress is calculated) and the potential limitations of the structural stress method are examined for various types of weldments. Based on the results from this study, it is expected to develop a more precise stress estimation technique for fatigue strength assessment of welded structures.

Modified DEBA for determining size dependent shear fracture energy of laminates

  • Goodarzi, M. Saeed;Hosseini-Toudeshky, Hossein
    • Steel and Composite Structures
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    • v.28 no.1
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    • pp.111-121
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    • 2018
  • It has been argued that fracture energy of composite laminates depends on their thickness and number of layers. In this paper a modified direct energy balance approach (DEBA) has been developed to evaluate the mode-II shear fracture energy for E-glass/Epoxy laminates from finite element model at an arbitrary thickness. This approach considers friction and damage/plasticity deformations using cohesive zone modeling (CZM) and nonlinear finite element modeling. The presence of compressive stress and resulting friction was argued to be a possible cause for the thickness dependency of fracture energy. In the finite element modeling, CZM formulation has been developed with bilinear cohesive constitutive law combined with friction consideration. Also ply element have been developed with shear plastic damage model. Modified direct energy balance approach has been proposed for estimation of mode-II shear fracture energy. Experiments were performed on laminates of glass epoxy specimens for characterization of material parameters and determination of mode-II fracture energies for different thicknesses. Effect of laminate thickness on fracture energy of transverse crack tension (TCT) and end notched flexure (ENF) specimens has been numerically studied and comparison with experimental results has been made. It is shown that the developed numerical approach is capable of estimating increase in fracture energy due to size effect.

Effect of a Finite Substrate on the Radiation Characteristics of a Linear Phased Array Antenna Positioned along the E-plane (유한한 기판 크기가 E-평면으로 배열된 선형 위상 배열 안테나의 방사 특성에 미치는 영향)

  • Kim, Tae-Young;Kim, Gun-Su;Yoon, Young-Min;Kim, Boo-Gyoun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.5
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    • pp.46-53
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    • 2011
  • The effect of a finite substrate on the radiation characteristics of a linear 7-element array antenna positioned along the E-plane is investigated. Active reflection coefficients and average active element patterns are simulated for various substrate sizes. The E-plane radiation pattern of a fully excited array for various scan angles is correlated with the active reflection coefficient and average acitive element pattern. The effect of E-plane substrate size on the radiation characteristics of a linear array along the E-plane is larger than that of H-plane substarte size.

Frequency characteristics and sensitivity analysis of a size-dependent laminated nanoshell

  • Dai, Zuocai;Jiang, Zhiyong;Zhang, Liang;Habibi, Mostafa
    • Advances in nano research
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    • v.10 no.2
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    • pp.175-189
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    • 2021
  • In this article, frequency characteristics, and sensitivity analysis of a size-dependent laminated composite cylindrical nanoshell under bi-directional thermal loading using Nonlocal Strain-stress Gradient Theory (NSGT) are presented. The governing equations of the laminated composite cylindrical nanoshell in thermal environment are developed using Hamilton's principle. The thermodynamic equations of the laminated cylindrical nanoshell are obtained using First-order Shear Deformation Theory (FSDT) and Fourier-expansion based Generalized Differential Quadrature element Method (FGDQM) is implemented to solve these equations and obtain natural frequency and critical temperature of the presented model. The novelty of the current study is to consider the effects of bi-directional temperature loading and sensitivity parameter on the critical temperature and frequency characteristics of the laminated composite nanostructure. Apart from semi-numerical solution, a finite element model was presented using the finite element package to simulate the response of the laminated cylindrical shell. The results created from finite element simulation illustrates a close agreement with the semi-numerical method results. Finally, the influences of temperature difference, ply angle, length scale and nonlocal parameters on the critical temperature, sensitivity, and frequency of the laminated composite nanostructure are investigated, in details.

Geochemical Dispersion and Enrichment of Fluvial Sediments Depending on the Particla Size Distribution (입도분포에 따른 하상퇴적물의 지구화학적 분산 및 부화)

  • 이현구
    • Economic and Environmental Geology
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    • v.32 no.3
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    • pp.247-260
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    • 1999
  • Geochermical characteristics of the fluvial sediments deprnding on particle size distribution size were investigated in the respect of majir, minor and rare eath element chemisitry. Ratios of $Al_{2}O_{3}/Na_{2}O$ and $K_{2}O/Na_{2}O$ of the sediments show the homogeneous valus, and partly positive correlation with $SiO_{2}/Al_{2}O_{3}$, respecively. Characteristics of minor element ratios (V/Ni, Cr/V, Ni/Co and Zr/Hf)are within the lower and narrow range. Thesesuggested that sediment sources may be acidic to intermediate granitic rock, and may be explained by simple weathering and sedimentation. With increasing SiO2 contents, concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, CaO and MgO decreased, but those of $K_{2}O$ and $Na_{2}O$ increased, Concentrations of Ba, Be, Cs, Cu, Li, Ni, Sr, V and Zr show comparatively normal negative and some positive trends. Compared with the mean composition of granite, concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, MnO, CaO and MgO in the sediments of the study area were highly enriced. Among some minor and rare earth elements, concentrations of As, Cd, Cu, and V were enriched, but those of Be, Ce, Rb, Sc, Sr and Zn were depleted when compared with average composition of granite. By decreasing of particle size fractions, SiO2, Rb and Sr conterts decreased, but concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, CaO, MgO, $TiO_{2}$, MgO, $P_{2}O_{5}$, Be, Cu, Hf, Pb, V and Zr increased. From the correlations between particle size fractions and element concenreations, some elements of $Fe_{2}O_{3}$, CaO, MgO, $P_{2}O_{5}$, Cu, Ni, Zn and Zr showed typical trends in the secondary contramination sediments. These trends are typically shown under 100 mesh fractions. It indicates that the fraction of minus 100 mesh is the optimum size fraction for geochemical and environmental survey.

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Automatic Quadrilateral Mesh Generation for Large Deformation Finite Element Analysis (대변형 유한요소해석을 위한 요소망 자동 생성기법)

  • 김동준;최호준;장동환;임중연;이호용;황병복
    • Transactions of Materials Processing
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    • v.12 no.3
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    • pp.194-201
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    • 2003
  • An automatic quadrilateral mesh generator for large deformation finite element analysis such as metal forming simulation was developed. The NURBS interpolation method is used for modeling arbitrary 2-D free surface. This mesh generation technique is the modified paving algorithm, which is an advancing front technique with element-by-element resolving method for paving boundary intersection problem. The mesh density for higher analysis accuracy and less analysis time can be easily controlled with high-density points, maximum and minimum element size. A couple of application to large deformation finite element analysis is given as an example, which shows versatility and applicability of the proposed approach and the developed mesh generator for large deformation finite element analysis.