• Title/Summary/Keyword: 파워흐름 유한요소법

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Analysis of Vibration of a Simple Plate In a Medium-to-High Frequency Range With Power Flow Finite Element Method (파워흐름유한요소법에 의한 중고주파수 영역에서 단순 평판의 진동 해석)

  • Seo, Seong-Hoon;Hong, Suk-Yoon;Kil, Hyun-Gwon;Huh, Young
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.2
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    • pp.125-131
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    • 2003
  • In this paper Power Flow Finite Element Method(PFFEM) has been implemented to analyze the vibration of a plate in mid and high frequency ranges. In order to solve the vibration energy governing equation in Power Flow Analysis(PFA), The Finite Element Method(FEM) was used as a numerical tool. It allowed one to predict the distribution of displacement and Intensity in the plate vibrating at mid and high frequencies. The results were compared with the analytical solutions and the approximate FEM solutions. The comparison showed that PFFEM can be an effective tool to analyze the structural vibration in mid and high frequency ranges.

Characteristics of PFFEM program and vibration analysis of automobile using the developed program (파워흐름유한요소해석 프로그램의 특성과 이를 이용한 자동차 진동해석)

  • 박영호;홍석윤;서성훈;길현권
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.1083-1088
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    • 2001
  • To predict vibrational energy density and intensity of complex structures in medium-to-high frequency ranges, Power Flow Finite Element Method(PFFEM) programs for the plate, beam and some coupled structural elements are developed at present. The vibration energy density and intensity of foreign vehicle is predicted successfully with FE full model of 60,000 DOF using the developed PFFEM program.

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Vibration Intensity Analysis of Penetration Beam-plate Coupled Structures (관통보와 평판의 연결 구조물에 대한 진동인텐시티 해석)

  • 홍석윤;강연식
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.1
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    • pp.73-81
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    • 2002
  • The transmission of vibration energy through beam-plate junctions in vibration intensity analysis called power new analysis (PFA) has been studied. PFA is an analytic tool for the prediction of frequency averaged vibration response of built-up structures at medium to high frequency ranges. The power transmission and reflection coefficients between the semi-infinite beam and plate are estimated using the wave transmission approach. For the application of the power coefficients to practical complex structures, the numerical methods, such as finite element method are needed to be adapted to the power flow governing equation. To solve the discontinuity of energy density at the joint, joint matrix is developed using energy flow coupling relationships at the beam-plate joint. Using the joint matrix developed in this paper, an idealized ship stem part is modeled with finite element program, and vibration energy density and intensity are calculated.

A Technique for Calculations of Power Flow in Structures Using MSC/NASTRAN and PCL (MSC/NASTRAN 및 PCL을 이용한 구조물 내의 진동 파워 흐름 해석 기법)

  • 홍진숙
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.8
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    • pp.303-313
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    • 2001
  • The identification of power flow in dynamically loaded structures Is essential in the analysis of structure-borne noise. However there are no general purpose tools to estimate powers flow. To make matters worse. It is very difficult to measure it. The power flow can be formulated in terms of balance forces(ELFORCE) at each element and velocities at the associated node obtained with MSC/NASTHAN. In this paper the procedure which is consist of the computations of the balance forces of al1 elements and the velocities at all nodes using MSC/NASTRAN. The calculations of the power f1ow at each element using PCL(PATRAN Command Language) and the Preparation of post -processes is set UP.

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Development of Sound Radiation Analysis System Using the Results of Power Flow Finite Element Method (파워흐름유한요소법의 진동해석 결과를 이용한 구조물의 방사소음 해석시스템 개발)

  • 이호원;홍석윤
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.7
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    • pp.21-30
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    • 2001
  • The analysis system implementing a serial process from structural vibration to sound radiation has been developed using both the power flow finite element method (PFFEM) known as a new vibrational analysis technique in medium to high frequency ranges and the acoustic boundary element method (BEM) which is effective in analyzing the sound radiation problems. The vibration analysis for arbitrary shape structures composed of plates is performed, and using the vibration energy density obtained from this analysis as the velocity boundary conditions for an acoustic analysis, vibro-acoustic analysis has been processed. To verify the developed system, we select a simple structure model and compare the results of developed system with those of SYSNOISE, and also the developed system is applied for the vibro-acoustic analysis of various structures in shapes.

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Vibration Experiments of the Cylindrical Structure for Verifying the Reliability of Power Flow Finite Element Method (파워흐름해석법의 신뢰성 검증을 위한 원통형 구조물의 진동실험)

  • 이호원;홍석윤;박영호;길현권;김창열;전재진;류정수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.290-297
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    • 2002
  • Vibration experiments have been performed to observe the analytic characteristics of power How finite element method(PFFEM) for the reinforced cylindrical structure. For this, the vibration experimental results are compared with the numerical solutions obtained by PFFEM in medium-to-high frequency ranges. Input Power into the experimental structure is measured using the impedance head adhered to the exciter, and that input power is used for the vibration analysis. Using the developed PFFEM program(PFADS), the reinforced cylindrical structure modeled by beam and plate elements is analyzed, and very reliable results for PFFEM are obtained by the comparisons of the experimental results.

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Underwater Radiated Noise Analysis for Commercial Ship Using Power Flow Analysis (파워흐름해석법을 이용한 상선의 수중방사소음해석)

  • Kwon, Hyun-Wung;Hong, Suk-Youn;Song, Jee-Hun
    • Journal of Ocean Engineering and Technology
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    • v.26 no.4
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    • pp.30-36
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    • 2012
  • Recently, the underwater radiated noises generated from large commercial ships have become a globally important issue. Countries with large ports and environmental protection organizations demand strict safety guidelines in relation to underwater radiated noise. In this paper, the coupled PFFE/PFBE method is used to investigate the vibration and underwater radiated noise of a commercial ship. PFFEM is employed to analyze the vibrational responses of the commercial ship, and PFBEM is applied to analyze the underwater radiation noise. The vibrational energy of the structure is treated as an acoustic intensity boundary condition of PFBEM to calculate the underwater radiation noise. Numerical simulations are presented for the commercial ship under various frequencies, and reliable results are obtained.

Research on Frequency Average Analysis of vibrational Power Flow Analysis (진동파워흐름해석의 주파수 평균해석에 대한 연구)

  • Lee, Jea-Min;Hong, Suk-Yoon;Park, Young-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.971-977
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    • 2005
  • Power Flow Analysis (PFA) is developed for the effective predictions of frequency-averaged vibrational response in medium-to-high frequency ranges. In PFA, the power coefficients of semi-infinite structure and for-field energy density are used to predict the vibrational responses of structures. Generally, at high frequencies, PFA can predict narrow-band frequency-averaged vibrational responses of built-up structures. However, in low- to medium frequency ranges, the dynamic responses obtained by PFA represent broad-band frequency-averaged vibrational energy densities. For the prediction of vibrational response variance in Power Flow Finite Element Method (PFFEM), the variances of input power and joint element matrix describing structural coupling relationship are derived. Finally, for the validity of developed formulation, numerical examples for two co-planer plates are performed and the vibrational response variance of the structure are compared with the results of classical and PFFEM solutions.

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Experimental Study On Power Flow Finite Element Method of Vibration of a Plate Partially Covered with a Damping Sheets (부분 제진 평판 진동 해석을 위한 파워흐름유한요소법의 실험적 연구)

  • Lee, Y.H.;Lee, J.Y.;Kil, H.G.;Hong, S.Y.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.04a
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    • pp.496-497
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    • 2009
  • In this paper the power flow finite element method (PFFEM) has been used to analyze the vibration of a plate partially covered with a damping sheet. Experiments have been performed to measure the loss factor and frequency response functions of the plate partially covered with the damping sheet. The data for the loss factor has been used as the input data to predict the vibration of the coupled plates with PFFEM. The comparison between the experimental results and the predicted PFFEM results for the frequency response functions has been performed. It showed that PFFEM can be effectively used to predict structural vibration in medium-to-high frequency ranges.

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Vibration and Noise Analysis for Rotary Compressor in Medium-to-high Frequency Ranges (중고주파수 대역의 회전형 압축기 진동소음 해석)

  • Kwon, Hyun-Wung;Song, Jee-Hun;Hong, Suk-Yoon;Hwa, Jong-Hun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.11
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    • pp.1033-1041
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    • 2012
  • Power flow analysis(PFA) is introduced for solving the noise and vibration analysis of system structures in medium-to-high frequency ranges. The vibration analysis software, $PFADS_{C++}$ R4 based on power flow finite element method(PFFEM) and the noise prediction software, $NASPFA_{C++}$ R1 based on power flow boundary element method(PFBEM) are developed. In this paper, the coupled PFFE/PFBE method is used to investigate the vibration and radiated noise of the rotary compressor. PFFEM is employed to analyze the vibrational responses of the rotary compressor, and PFBEM is applied to analyze the radiation noise around rotary compressor. The vibrational energy of the structure is used as an acoustic intensity boundary condition of PFBEM. Numerical simulations are presented for the rotary compressor, and reliable results have been obtained.