• 한국전산구조공학회논문집
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• 제16권2호
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• pp.125-131
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• 2003

본 논문에서는 중고주파수 영역에서 진동하는 단순평판의 진동을 해석하기 위하여 파워흐름유한요소법을 적용하였다. 파워흐름해석법에서 주어지는 진동 에너지지배방정식의 해를 구하기 위한 수치해석 도구로써 유한요소법을 활용하였다. 이러한 파워흐름유한요소법을 적용하여 중고주파수 영역에서 진동하는 단순평판의 진동 변위와 진동인텐시티 분포를 구하였다. 또한 수치해 결과를 엄밀해와 유한요소법에 의한 근사해와 비교함으로써, 파워흐름유한요소법은 중고주파수 영역에서 진동 변위 및 진동 인텐시티를 예측하기 위하여 효과적으로 적용될 수 있음을 보였다.

• 한국음향학회지
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• 제21권1호
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• pp.73-81
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• 2002

본 논문에서는 중고주파영역에서의 진동해석기법인 파워흐름해석 법을 보와 평판이 연성된 구조물에 적용하기 위하여 무한보가 무한평판을 수직으로 투과하는 구조물에서의 파워투과반사계수를 파동전달법을 이용하여 구하였다. 이러한 파워투과반사계수를 실제 구조물에 적용하기 위해서는 파워흐름유한요소법으로의 활용이 필요하다. 이를 위해 본 논문에서는 파워투과반사계수를 이용하여 보 평판구조물을 위한 연결요소행렬식을 정립하였으며, 또한 보와 평판요소를 각각 해석할 수 있는 파워흐름유한요소해석 프로그램을 구성하고, 여기에 정립된 보와 평판간의 연결요소 행렬식을 대입하여 보와 평판이 연성된 구조물까지 해석이 가능한 프로그램으로 개발하였다. 이 프로그램을 이용하여 이상화한 선박의 선미부 구조물을 해석한 결과, 선박구조물에서 진동에너지분포를 구할 수 있었고, 진동 인텐시티를 통하여 구조물에서의 파워전달경로를 예측할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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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.

• 한국음향학회지
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• 제20권7호
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• pp.21-30
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• 2001

중고주파수 대역에서 구조물의 진동해석에 사용되는 새로운 기법인 파워흐름유한요소법과 음향방사문제를 해결하는데 사용되는 음향경계요소법을 이용하여 구조물의 진동해석에서 방사소음해석까지 일련의 과정이 순차적으로 이루어지는 해석시스템을 구축하였다. 평판으로 이루어진 임의의 형상 구조물의 진동해석을 수행하고, 이 때 얻어지는 표면에서의 에너지밀도를 음향해석을 위한 속도경계조건으로 활용하여 진동-소음해석을 수행하였다. 개발된 진동-소음해석 시스템의 검증을 위해 간단한 형상의 구조물을 모델링하여 상용화 패키지(SYSNOISE)의 해석결과와 비교하였으며 또한 여러 다양한 형상의 구조물에 대해서도 본 해석시스템을 적용하여 진동-소음해석을 수행하였다.

• 한국소음진동공학회논문집
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• 제11권8호
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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.

• 한국해양공학회지
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• 제26권4호
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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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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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.

• 한국소음진동공학회논문집
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• 제20권1호
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• pp.74-82
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• 2010

Power flow analysis(PFA) methods have shown many advantages in noise predictions and vibration analysis in medium-to-high frequency ranges. Applying the finite element technique to PFA has produced power flow finite element method(PFFEM) that can be effectively used for analysis of vibration of complicated structures. PFADS(power flow analysis design system) based on PFFEM as the vibration analysis program has been developed for vibration predictions and analysis of coupled structural systems. In this paper, to improve the function of vibro-acoustic coupled analysis in PFADS, the PFFEM has been extended for analysis of the interior noise problems in the vibro-acoustic fully coupled systems. The vibro-acoustic fully coupled PFFEM formulation based on energy coupled relations is extended to structural system model by using appropriate modifications to structural-structural, structural-acoustic and acoustic-acoustic joint matrices. It has been applied to prediction of the interior noise in two room model coupled with panels, and the PFFEM results are compared to those of statistical energy analysis(SEA).

• 한국소음진동공학회논문집
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• 제22권11호
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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.