• Title/Summary/Keyword: Finite Thrust

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A Study on the Stress and Strain Analysis of Human Muscle Skeletal Model in Kendo Three Typical Attack Motions (세 가지 주요 검도 공격 동작에서의 근-골격계 응력과 번형률 해석에 관한 연구)

  • Lee, Jung-Hyun;Lee, Young-Shin
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.9
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    • pp.126-134
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    • 2008
  • Kendo is one of the popular sports in modem life. Head, wrist and thrust attack are the fast skill to get a score on a match. Human muscle skeletal model was developed for biomechanical study. The human model was consists with 19 bone-skeleton and 122 muscles. Muscle number of upper limb, trunk and lower limb part are 28, 60, 34 respectively. Bone was modeled with 3D beam element and muscle was modeled with spar element. For upper limb muscle modelling, rectus abdominis, trapezius, deltoideus, biceps brachii, triceps brachii muscle and other main muscles were considered. Lower limb muscle was modeled with gastrocenemius, gluteus maximus, gluteus medius and related muscles. The biomechanical stress and strain analysis of human muscle was conducted by proposed human bone-muscle finite element analysis model under head, wrist and thrust attack for kendo training.

A Study of Natural Frequency on Offshore Wind Turbine Structural Change (해상 풍력 발전용 구조물 변화에 따른 고유진동해석)

  • Lee, Kang-Su;Lee, Jung-Tak;Son, Choong-Yul
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.1008-1016
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    • 2007
  • The purpose of this paper is to investigate the Natural Frequency behavior characteristic of Wind Turbine Tower model, and calculated the stress values of thrust load, wave load, wind load, current load, and gravity load. The offshore Jacket Type Tower which was installed in Vitenam South China Sea is used for the study. Natural frequency and mode shape are calculated with commercial program using the measured vibration. The finite element analysis is performed with commercial F.E.M program(ANSYS) on the basis of the natural frequency and mode shape.

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Dual-Halbach Array Permanent Magnet Tubular Generator for Free-Piston Generator

  • Beigi, Hassan Moradi Cheshmeh;Akbari, Sohrab
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.405-412
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    • 2015
  • In this study, we describe the effects of changing the magnet shape of permanent magnets (PMs) in a rotor Halbach-array PM generator for reciprocating free piston generator applications. More specifically, the rectangular-shaped magnets were replaced by the trapezoidal-shaped magnets. The initial design, an analytical magnetic field solution of rectangular shaped magnets, is presented and air-gap magnetic flux density and thrust force were estimated. The results were compared to the finite element analysis (FEA) showing excellent agreement. Using FEA, the effect of the shape of the magnets on the flux density and thrust force waveforms is analyzed. Moreover, the proportion of the Halbach array in the machine was optimized by the means of a parametric search. The results obtained from the analytical calculations and FEA were validated by comparing to those of Radial-array PM generator.

A Study of Natural Frequency of Offshore Wind Turbine JACKET (해상 풍력 발전 JACKET의 고유진동수에 관한 연구)

  • Lee, Kang-Su;Lee, Jung-Tak;Son, Choong-Yul
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.2 s.119
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    • pp.130-135
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    • 2007
  • The purpose of this paper is that investigates the Natural Frequency behavior characteristic of wind turbine jacket type tower model, and calculated that the stress values of thrust load, wave load, wind load, current loda, gravity load, etc., environment evaluation analysis during static operating wind turbine jacket type tower model, carried out of natural frequency analysis of total load case to stress matrix, frequency calculated that calculated add natural frequency to stiffness matrix for determinant to stress results. The finite element analysis is performed with commercial F.E.M program (ANSYS) on the basis of the natural frequency and mode shape.

Analysis for The Characteristic Thrust Force in 2 Phase 8 Pole LPM Using Finite Elemnet Method (유한요소법을 이용한 2상8극형 LPM의 구동방식에 따른 정추력해석)

  • Lee, Eun-Woong;Cho, Hyun-Kil;Kim, Sung-Heon;Kim, Il-Jung;Lim, Su-Saeng
    • Proceedings of the KIEE Conference
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    • 1997.07a
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    • pp.238-240
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    • 1997
  • In two case, LPM driving by full step or microstep, we simulated the thrust force in LPM using finite element method and measured the force by experimental equipment. And We analyze the harmonics of trust force by Fast Fourier Transform. We proposed the method, which can reduced harmonic force by microstep driving.

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Effect of Airgap Length Difference on the Characteristics of the Double-Sided Linear Pulse Motor (공극 길이 차이가 양측식 리니어 펄스 모터의 특성에 미치는 영향)

  • 이동주;이은웅;김성현;손홍관;김성종
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.1
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    • pp.1-8
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    • 2003
  • Generally, thrust force of double-sided LPM is more powerful than that of single-sided LPM. Also, double-sided LMP can be effectively applied to the high-precision position system with its simple control scheme. However, An equality between two airgap lengths Is a necessary condition for its high performance. If a little difference between two airgaps is existed, unbalanced normal force and undesirable vibration will be generated. Additionally, even though two airgap lengths are absolutely same, undesirable vibration can be generated because the direction of instantaneous normal force on mover is changed according to excitation methods. An effect of inequality of two airgap lengths is presented in this paper. Distribution of airgap permeance vs. relative displacement is analyzed by two dimensional finite element method. Excitation From this results, current waveforms to reduce the undesirable vibration is proposed.

Detent Force Minimization Techniques in Permanent Magnet Linear Synchronous Motor (영구자석 선형동기전동기의 디텐트력 저감법)

  • Lim, Ki-Chae;Woo, Joon-Keun;Hong, Jung-Pyo;Kim, Gyu-Tak
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.11
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    • pp.749-756
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    • 2000
  • Detent force develops generally undesirable effect that contributes to the output ripple of machine, vibration and noise. This paper proposes detent force minimization techniques for a Permanent Magnet Linear Synchronous Motor (PMLSM). In addition, thrust according to each minimization technique is estimated to observe the change of machine performance. A two-dimensional Finite Element Method is used to predict detent force and thrust due to structural factors and non-linearity. And moving node technique for geometric models is proposed to reduce modeling time and efforts.

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Improvement of Control Characteristics of Permanent Magnet Linear Synchronous Motor by Compensation of Thrust Ripple (추력리플 보상을 통한 영구자석형 선형 동기전동기의 제어특성 향상)

  • Jung, In-Soung;Hyun, Dong-Seok
    • Proceedings of the KIEE Conference
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    • 1998.11a
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    • pp.16-18
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    • 1998
  • In this paper, a control method based on finite element analysis is presented to reduce the thrust ripple of the permanent magnet linear synchronous motor (PMLSM). In the control method, additional compensation current is added to the conventional control current according to the position of mover. The exact value of the compensation current is calculated from finite element analysis. To conform the validity of the presented method, a test set is built and experiments are performed.

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Transverse Flux Linear Machine with High Thrust for Direct Drive Applications

  • Chang, Jung-Hwan;Kim, Ji-Won;Kang, Do-Hyun;Bang, Deok-Je
    • Journal of Magnetics
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    • v.15 no.2
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    • pp.64-69
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    • 2010
  • This paper describes the development of a novel transverse flux linear motor (TFLM) excited by permanent magnets (PMs). It combines the advantage of two different TFLMs and produces high thrust with reduced normal force. The magnetic field is analyzed by combining the three-dimensional (3D) equivalent magnetic circuit network (EMCN) method with 2D finite element analysis. The experimental findings of the prototype motors are in good agreements with the analysis results, and demonstrate the potential of the proposed motor as a direct drive requiring relatively long displacement of a mover.