• Title/Summary/Keyword: femA

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A Study on the Vibration Characteristics Analysis of Composite Materials by Using Electronic Speckle PatternInterferometry Method (전자처리 스페클 패턴 간섭법을 이용한 복합재료의 진동 특성 해석에 관한 연구)

  • 김형택;정현철;양승필
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.388-392
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    • 1995
  • The Electronic Speckle Pattern Interferometry(ESPI) has been applied to many technical problems such as deformation and displacement measurement, strain visualization and surface roughness monitoring. Composite materials have various complicated characteristics depending on the ply materials,ply orientations,ply stacking sequences and boundary conditions. Therefore, it is difficult to analyze composite material. For efficient use of composit materials in engineering applications, the dynamic behavior such as, natural frequencies and modal patterns should be identified. This studying presents FEM results for the free vibration of symmetrically laminated composite as [30/-30/90] $_{s}$. The natural frequencies of laminated composite rectangular plates having the boundary condition(:2-edge clamped) are experimentally obtained. In order to demonstrate the validity of the experiment,FEM analysis using ANSYS was performed and natural frequencies experimentally obtained is compared with calculated by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.t.

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Study on Torque Analysis and Armature Shape Optimization of Electromagnetic Clutch by Using FEM (FEM을 이용한 Electromagnetic Clutch 토크해석과 전기자 치수최적화)

  • Piao, Changhao
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.5
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    • pp.245-249
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    • 2006
  • This study tries to test and analyze the static friction torque generated by an electromagnetic clutch. Then the torque is improved by optimizing the shape of armature. For the purpose of design change and optimization of the electromagnetic clutch, the static friction torque prediction is very important. We construct an axi symmetric FEM model for analyzing the static friction torque and used a torque tester for evaluating the real torque. For a test, predicted static friction torque is compared with the experimental one to discuss the rationality of torque analysis process. The analytical result agrees well with experimental data, explaining the validity of the mathematical process and FEM model. After confirming the torque analysis process, the optimization process is investigated. The optimization result shows that the static torque is improved by changing the armature shape.

Design of Ultrasonic Vibration Tool Horn for Micromachining Using FEM (유한요소법을 이용한 초음파 진동 공구혼 설계에 관한 연구)

  • Lee, Bong-Gu;Kim, Kwang-Lae;Kim, Kang-Eun
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.6
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    • pp.63-70
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    • 2008
  • Conical horn is used in many high frequency ultrasonic horns, to achieve a longitudinal vibration mode across a wide ultrasonic tool horn output surface. Modal analysis is method for designing tuned ultrasonic tool horn and for the prediction natural frequency of ultrasonic tool horn vibration mode. The design of ultrasonic horn is based on prototype estimate obtained by FEM analysis. The FEM simulated ultrasonic tool horn is built and characterized experimentally through laser vibrometer and electrical impedance analysis. In this paper, FEM analysis is developed to predict the natural frequency of ultrasonic tool horn and use of in the optimal design of ultrasonic horn shape.

Slope Stability Analysis Considering Seepage Conditions by FEM Using Strength Reduction Technique (강도 감소법에 의한 지하수위를 고려한 FEM 사면안정해석)

  • 김영민
    • Journal of the Korean Geotechnical Society
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    • v.20 no.8
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    • pp.97-102
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    • 2004
  • In this paper, a finite element based method far determining factor of safety of slopes which has certain advantages over conventional limit equilibrium methods is described. Particularly, the slope failure behaviour considering different seepage conditions is produced by finite element method using strength reduction technique. It is shown that both the failure mechanism and the safety factor that are analyzed by the FEM using strength reduction technique are an effective means of slope stability analysis. And the stability of a slope with rising water table and rapid drawdown are analyzed and the results are compared with the simplified Bishop Method of the Limit Equilibrium Methods.

Stress Analysis of the Prestressed Dies by Using FEM (유한요소법을 이용한 예압된 금형의 응력해석)

  • Yeo, Hong-Tae;Choi, Young;Hur, Kwan-Do
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.6
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    • pp.114-122
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    • 1999
  • By using the FEM, a method for the stress analysis of the presented dies has been proposed. In this method, FEM and Lame equation are used for the analysis of the die insert and the stress ring, respectively. The proposed method includes the calculation of the contact pressure between the die insert and the stress ring. To show the validity, the proposed method has been applied to the simple test problem. The results of the stress analysis have been compared with the results of ANSYS, a commercial FE-code. Cold extrusion has been simulated by using the rigid-plastic FEM and the results of the deformation analysis have been used as the input of the die structure analysis. The stress states of the prestressed extrusion die have been obtained. The stress analysis of the die insert with stress rings has also been performed during extrusion.

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Comparative study between Finite Element Method and Limit Equilibrium Method on Slope Stability Analysis (사면안정해석에 있어서의 유한요소법과 한계평형법의 비교)

  • 이동엽;유충식
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.483-490
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    • 2002
  • This paper presents the results of a comparative study between FEM and LEM on slope stability analysis. For validation, factors of safety were compared between FEM and LEM. The results from the two methods were in good agreement suggesting that the FEM with the shear strength reduction method can be effectively used on slope stability analyses. A series of analysis were then performed using the FEM for various constitutive laws, slope angles, flow rules, and the finite element discretizations. Among the findings, the finite element method in conjunction with the shear strength reduction method can provide reasonable results in terms of factor of safety. Also revealed is that the results of FEM can be significantly affected by the way in which the type of constitutive law and flow rule are selected.

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