• Title/Summary/Keyword: Galerkin%27s approach

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Numerical Calculation of Longitudinal Current Distribution in Grounding Electrode for Analyzing the Grounding Impedance (접지임피던스 분석을 위한 접지전극의 전류분포 수치계산)

  • Cho, Sung-Chul;Lee, Bok-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.1
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    • pp.46-52
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    • 2013
  • The current distribution passing through grounding electrode is required for calculating an impedance of grounding electrode using the electromagnetic field model. In this paper the numerical calculation for currents passing through a grounding electrode as a function of frequency was given. The proposed approach is based on the wire antenna model(AM) in the frequency domain. The Pocklington's equation driven from the wire antenna theory was numerically calculated by the Galerkin's method. The triangle function was applied to both the basis function and the weighting function. The current distribution of a horizontal ground electrode was simulated in MATLAB. Also these results were compared with the data obtained from the CDEGS HIFREQ calculation.

Formulation of Fully Coupled THM Behavior in Unsaturated Soil (불포화지반에 대한 열-수리-역학 거동의 수식화)

  • Shin, Ho-Sung
    • Journal of the Korean Geotechnical Society
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    • v.27 no.3
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    • pp.75-83
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    • 2011
  • Emerging issues related with fully coupled Thermo-Hydro-Mechanical (THM) behavior of unsaturated soil demand the development of a numerical tool in diverse geo-mechanical and geo-environmental areas. This paper presents general governing equations for coupled THM processes in unsaturated porous media. Coupled partial differential equations are derived from three mass balances equations (solid, water, and air), energy balance equation, and force equilibrium equation. With Galerkin formulation and time integration of these governing equations, finite element code is developed to find nonlinear solution of four main variables (displacement-u, gas pressure-$P_g$), liquid pressure-$P_1$), and temperature-T) using Newton's iterative scheme. Three cases of numerical simulations are conducted and discussed: one-dimensional drainage experiments (u-$P_g-P_1$), thermal consolidation (u-$P_1$-T), and effect of pile on surrounding soil due to surface temperature variation (u-$P_1$-T).