• Title/Summary/Keyword: finite-element modeling

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Estimation Of Footing Settlement In Sand (사질토 지반에서의 얕은기초 침하량 해석)

  • Lee, Jun-Hwan;Park, Dong-Gyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.44-49
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    • 2004
  • The settlements of footings in send are often estimated based on the results of in-situ tests, particularly the standard penetration test (SPT) and the cone penetration test (CPT). In this paper, we analyze the load-settlement response of vertically loaded footings placed in sands using both the finite element method with a non-linear stress-strain model and the conventional elastic approach. Calculations are made for both normally consolidated and heavily overconsolidated sands with various relative densities. For each case, the cone penetration resistance qc is calculated using CONPOINT, a widely tested program that allows computation of qc based on cavity expansion analysis. Based on these analyses, we propose a procedure for the estimation of footing settlement in sands based on CPT results.

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Optimum Geometric and Electrical Parameter for Minimization Torque Ripple of Switched Reluctance Motor (스위치드 릴럭턴스 전동기의 토오크 리플 저감을 위한 기하학적인 파라미터와 전기적인 파라미터의 최적화)

  • Choi, Jae-Hak;Kim, Sol;Lee, Kab-Jae;Lee, Ju;Hong, Kyung-Jin;Choi, Dong-Hoon
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.3
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    • pp.93-100
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    • 2003
  • Switched reluctance motor(SRM) has some advantages such as low cost, high torque density but SRM has essentially high torque ripple due to its salient structure. In order to apply SRM to industrial field, torque ripple has to be reduced. This paper introduces optimal design process of SRM using an optimization algorithm of Progressive Quadratic Response Surface Modeling(PQRSM) and two-dimensional(2D) Finite Element Method(FEM). The electrical and geometrical design parameters have been adopted as 2D design variables. From this work, it can be obtained both the optimal design minimized torque ripple and the optima1 design maximized the average torque, respectively. Finally, this Paper Presents Performance comparison of two optimal designs and consider influence of the selected design variables in torque characteristics.

The Insulation Design of Enclosure for Diagnostic Device in Extra High Voltage Line (초고압 선로 진단장치용 외함 절연설계)

  • Kim, Ki-Joon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.3
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    • pp.201-207
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    • 2015
  • In this paper, in order to avoid equipment malfunction due to electromagnetic waves, which can occur when high-voltage live line diagnostic device fabrication, the enclosure structure of the diagnostic device with power lines that can minimize the EMI (electromagnetic interference) was modeled using the FEM (finite element method). Simulation examined the strength of the electric field in the required thickness, material and regions where there is a control board while changing the curvature radius of the corner making the enclosure, and By applying a mechanical design and simulation results that occur during the actual production has been designed for the final design. Most of the simulation results for the electric field is concentrated in the final model, the inner edge of the enclosure could be confirmed that the stable structure.

Comparison and Analysis of Armature Reaction Magnetic Field of Linear Generator with Coreless/Cored Type Three Phases Concentrated Winding by using Space Harmonic Analytical Method (3상 집중권 권선을 갖는 코어리스/코어드 타입 리니어 발전기의 공간고조파 해석법을 이용한 전기자 반작용 자계특성 해석)

  • Seo, Sung-Won;Koo, Min-Mo;Kang, Han-Bit;Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.1
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    • pp.64-71
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    • 2015
  • This paper deals with analysis of armature reaction magnetic field of linear generator with three phases coreless/cored type concentrated winding. On the basis of a magnetic vector potential and Maxwell's equations, governing equations to predict armature reaction field are derived, and current density modeling is also performed analytically by using the Fourier series expansion. The analytical method used in this paper is confirmed by comparing with finite element analysis results.

Large Scale Numerical Analysis for the Performance Prediction of Multilayered Composite Curved Actuator (적층 복합재료를 사용한 곡면형 작동기의 성능 예측을 위한 대규모 수치해석 연구)

  • 정순완;황인성;김승조
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.10a
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    • pp.167-170
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    • 2003
  • In this paper, the electromechanical displacements of curved actuators using laminated composites are calculated by finite element method to design the optimal configuration of curved actuators. To predict the pre-stress in the device due to the mismatch in coefficients of thermal expansion, the carbon-epoxy and glass- epoxy as well as PZT ceramic is also numerically modeled by using hexahedral solid elements. Because the modeling of these thin layers causes the numbers of degree of freedom to increase, large-scale structural analyses are performed in a cluster system in this study. The curved shape and pre-stress in the actuator are obtained by the cured curvature analysis. The displacement under the piezoelectric force by an applied voltage is also calculated to compare the performance of curved actuator. The thickness of composite is chosen as design factor.

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A Study on the Pulsatile Characteristics of Blood flow in the Middle Cerebral Artery (중대뇌동맥내 혈류의 맥동특성에 관한 연구)

  • Jang, Dong-Sik;Lee, Yeon-Won;Oshima, Marie
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1930-1935
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    • 2003
  • The aim of this study is to apply engineering modeling tools to examine hemodynamics such as blood flow patterns or shear stress distributions, in order to determine the link between hemodynamics and cerebral aneurysms. Image-Based Simulation is used to analyze the realistic middle cerebral artery constructed from computed tomography raw data. As a result of simulation, high wall shear stress is appeared at the bifurcated region. And existence of the recirculation flow at the inlet of bifurcation($D_2$) is predict to affect at the development of the cerebral aneurysm.

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A New Approach of Multi-Scale Simulation for Investigating Nano-Scale Material Deformation Behavior (나노스케일 재료 변형 거동을 위한 새로운 멀티스케일 접근법)

  • Park, Junyoung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.8 no.1
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    • pp.43-47
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    • 2009
  • Recently, an approach for nano-scale material deformation has been developed that couples the atomistic and continuum approaches using Finite Element Method (FEM) and Molecular Dynamics (MD). However, this approach still has problems to connect two approaches because of the difference of basic assumptions, continuum and atomistic modeling. To solve this problem, an alternative way is developed that connects the QuasiMolecular Dynamics (QMD) and molecular dynamics. In this paper, we suggest the way to make and validate the MD-QMD coupled model.

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Shape Optimization for Opening Mode in Fracture Mechanics (열림 모드에 대한 형상 최적화)

  • 한석영;송시엽
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.04a
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    • pp.40-45
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    • 2001
  • The relationship between structural geometry and number of life cycles to failure is investigated to improve the fatigue life of structural components. The linear elastic fracture mechanics(LEFM) approach is integrated with shape optimal design methodology. The primary objective of this study is to decide an optimal shape for enhancing the life of the structure. The results from LEFM analyses are used in the fatigue model to predict the life of the structure before failure is occurred. The shape of the structure is optimized by using the growth strain method. Relevant issues such as problem formulation, finite element modeling are explained. Three design examples are solved, and the results show that, with proper shape changes, the life of structural systems subjected to fatigue loads can be enhanced significantly.

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Structural Analysis of Multi-size Power Chuck for Lathes (선반용 멀티사이즈 파워 척의 구조해석)

  • 김문기;유중학;윤영한;국정한;박종권
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.3
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    • pp.107-113
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    • 1999
  • The purpose of this study is to analyze multi-size power chuck which can chuck work pieces having various sizes automatically and be used suitably to an exclusive product line in the field of automotive industry. Gripping force, accuracy, and stiffness about the chuck are especially considered for the analysis. MSC/NASTRAN software is used for FEM analysis. Also, the effects of centrifugal force which occurs when chuck body rotates and compressive stresses which occur at contacting area in between chuck body and collet are estimated.

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Approximate Modeling of Doctor Blade Contact Pressure for Realization of Uniform Image Quality (균일 화상 품질 구현을 위한 닥터 블레이드 접촉압력 근사모델링)

  • Choi, Ha-Young;Park, Seung Chan;Lee, Jongsoo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.2
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    • pp.241-247
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    • 2013
  • The doctor blade is equipped in a toner cartridge and is a device to maintain the uniform thickness of a toner by controlling the pressure on the developing roller. The contact pressure between the developing roller and the doctor blade is one of the significant factors for image quality and durability of toner cartridge. The purpose of this study is to develop approximation model in order to minimize the time and cost which are needed much required in making optimal design of the doctor blade. Central composite design was used for the design of experiment and response surface design was used for approximation. The data for contact pressure were acquired through finite element analysis and data of image density and toner weight were acquired through experiment. The approximation model developed in this study has presented very high fitness.