• 대한토목학회논문집
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• 제29권6A호
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• pp.617-624
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• 2009

이 논문은 선형 변단면 정확탄성곡선형 아치의 자유진동에 관한 연구이다. 정확탄성곡선형 아치의 선형은 Bernoulli-Euler 보 이론을 이용하여 산정하였다. 이러한 선형을 갖는 아치의 자유진동을 지배하는 미분방정식을 유도하고 이를 수치해석하여 무차원 고유진동수를 산출하였다. 수치해석 예에서는 세 종류의 선형 변단면과 두 종류의 지점조건을 채택하였다. 이 연구의 결과를 검증하기 위하여 이 연구와 SAP 2000의 고유진동수를 비교하였다. 수치해석의 결과로 지점조건, 변단면 형상, 세장비 및 단면비가 최저차 4개의 무차원 고유진동수에 미치는 영향을 분석하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 추계학술대회 논문집
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• pp.77-82
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• 2010

In this work, a new active hybrid mount featuring piezostack actuator and rubber element is proposed, and its vibration control performance is evaluated by applying a robust frequency-shaped sliding mode controller. After describing the configuration of the proposed mount, vibration control performances are experimentally evaluated. A mount system with four active hybrid mounts is then constructed. To attenuate vibrations on the supported mass, a frequency-shaped sliding mode controller is designed and implemented to the system. Finally, control performances are obtained and presented in time and frequency domains via computer simulation.

• 소음진동
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• 제10권2호
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• pp.325-330
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• 2000

A dynamic absorber is used to protect the primary vibration system under the steady-state harmonic disturbance. In a number of cases it appears expedient to install several absorbers of smaller masses instead of one. This may be due to the need of distribute the absorber's response along the construction, restrictions on the absorber's installation. So, we studied characteristics of the primary vibration system for the optimal natural frequency ratio and the optimal damping ratio of serial multi-dynamic absorber. Also we obtained the optimum values of the serial multi-dynamic absorber parameters using computer simulation for the damped primary vibration system. In designing multi-dynamic absorber, we presented for the optimal natural frequency and the optimal damping ratio of multi-dynamic absorbers.

• 한국소음진동공학회논문집
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• 제21권1호
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• pp.24-30
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• 2011

In this work, a new active hybrid mount featuring piezostack actuator and rubber element is proposed, and its vibration control performance is evaluated by applying a robust frequency-shaped sliding mode controller. After describing the configuration of the proposed mount, vibration control performances are experimentally evaluated. A mount system with four active hybrid mounts is then constructed. To attenuate vibrations on the supported mass, a frequency-shaped sliding mode controller is designed and implemented to the system. Finally, control performances are obtained and presented in time and frequency domains via computer simulation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.797-800
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• 2006

The power flow analysis(PFA) can be effectively used to predict structural vibration in medium-to-high frequency ranges. In this paper, vibration experiment has been performed to observe the analytical characteristics of the power flow analysis of the vibration of a plate. In the experiment, the loss factor of the plate and the input mobility at a source point have been measured. The data for the loss factor has been used as the input data to predict the vibration of the plate with PFA. The frequency response functions have been measured over the surface of the plate. The comparison between the experimental results and the predicted results for the frequency responsefunctionshasbeenperformed.

• 소음진동
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• 제5권3호
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• pp.373-383
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• 1995

From the viewpoint of the structural design, the principal problem of the heat exchanger is the potentiality of structural instabilities due to the fluid loading effect during operations. Excessive fluid loading may give rise to permanent deformation of tube and would enentually result in collapse of heat exchanger, which would cause an obstruction of the fluid flow in the narrow channels. In this study, a fluid-structural interaction model was developed to investigate analtically the vibration characteristics of thin rectangular tube used in the heat exchanger. The model consists of two flat plates separated by fluid. The effects of the fluid in the tube was stuided. For analyses, the natural frequency coefficients of the model were investigated for the plate aspect ratios, channel heights, and boundary conditions. As conclusions, the natural frequency coefficients of the tube is found to be affected largely by the fluid loading and the channel heights.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.1054-1059
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• 2002

A linearly tapered beam immersed partially in other material is considered and is modelled as a linearly tapered Bernoulli-Euler beam fixed at the bottom with a concentrated mass at the top. Its governing equations is derived and its free vibration analysis is performed for various boundary conditions. And the rotatory inertia of the eccentric lumped tip mass is considered. The problem of determining the natural frequencies leads to an eighth order determinant. The solutions of the frequency equations are obtained numerically. The non-dimensional frequency parameters are given in tabular form and the influence of non-dimensional parameters on natural frequency is discussed for various conditions.

• 한국소음진동공학회논문집
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• 제22권12호
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• pp.1157-1163
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• 2012

Natural frequency of a nano-resonator via nano transfer printing is studied. Through a nano transfer printing, the hybrid metal/polymer membrane may evolve a wrinkle. Natural frequency of a wrinkled hybrid membrane decreases significantly, as the amplitude to wavelength ratio becomes larger. To address the design limit of a hybrid nano resonator, we perform parametric study using finite element analysis. Specifically, we study the effects of the Young's modulus ratio of the metal/polymer membrane, thickness ratio and wrinkle amplitude to wavelength ratio, respectively. The results from the parametric studies can serve as guideline to design hybrid nano resonators.

• 한국소음진동공학회논문집
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• 제15권3호
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• pp.329-333
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• 2005

This paper is concerned with the measurement of low-frequency vibrations of structures using the image processing method. To measure the vibrations visually, the measurement system consists of a camera, an image grabber board, and a computer. The specific target installed on the structure is used to calculate the vibration of structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the size of image. In this paper, we propose the methodology for the vibration measurement using the image processing method. The method enables us to measure the displacement directly without any contact. The current resolution of the vibration measurement is limited to sub centimeter scale. However, the frequency bandwidth and resolution can be enhanced by a high-speed and high-resolution image processing system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.194-201
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• 2001

The dynamic characteristic of the building using preflex composite beams is a low natural frequency due to long span. Therefore, both vibrational acceleration and the characteristic of natural frequency damage to people using the building, This study estimates a vibrational acceleration based on walking and natural frequency in five kinds of building. Recently, using methods of evaluating a serviceability are based on JIA, AISC, Eurocode, CSA, DIN and ISO. ed. The result of this study is content with foreign regulations and serviceability. However, considering of these results, the method of evaluating serviceability should be developed in the future.