• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.275-276
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• 2013

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.815-818
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• 2006

This paper deals with the free, in-plane vibrations of curved members with the translational(radial and tangential directions) and rotational springs at the ends. The governing differential equations for the circular curved member are solved numerically using the corresponding boundary conditions. The lowest three natural frequencies and the corresponding mode shapes are obtained over a range of non-dimensional system parameters: the subtended angle, the slenderness ratio, the translational spring stiffness, and the rotational spring stiffness.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.848-851
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• 2002

In this paper, an experimental method using a reference accelerometer has been developed to measure the in-plane vibration intensity of a beam. It has the advantages of reducing accelerometer phase error comparing with the cross spectral intensity measurement technique using an accelerometer array. It needs no measurement of the input force required in the frequency response method using the only one accelerometer This method has been used to measure the in-plane vibration intensity over the beam. The result has been compared with an input power and the vibration intensity obtained with other methods. It showed that the present experimental method can be effectively used to measure the structural in-plane vibration intensity.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.252-257
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• 2004

Free vibration of a semi-circular pipe conveying fluid is analyzed when the pipe is clamped at both ends. To consider the geometric non-linearity, this study adopts the Lagrange strain theory and the extensibility of the pipe. By using the extended Hamilton principle, the non-linear partial differential equations are derived, which are coupled to the in-plane and out-of\ulcornerplant: motions. To investigate the vibration characteristics of the system, the discretized equations of motion are derived from the Galerkin method. The natural frequencies are computed from the linearized equations of motion in the neighborhood of the equilibrium position. From the results. the natural frequencies for the in-plane and out-of-plane motions are vary with the flow velocity. However, no instability occurs the semi-circular pipe with both ends clamped, when taking into account the geometric non-linearity explained by the Lagrange strain theory.

• 한국소음진동공학회논문집
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• 제24권10호
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• pp.780-787
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• 2014

This paper experimentally deals with the vibration characteristics of flat ring transducers used for ultrasonic sensors and actuators. Radial vibration mode, which is the fundamental mode of a thin piezoelectric transducer, was measured by a laser in-plane vibrometer. An impedance analyzer was used to measure natural frequencies. The results measured by experiments verified theoretical predictions. The vibration characteristics of ring transducers were identified according to the outer diameter size. The shape of the fundamental mode is almost uniform but slightly decreases from the inner to the outer circumferential surfaces. The natural frequency of the fundamental mode decreases as the outer diameter increases. It appears that the ring type transducer is suitable to excite uniformly distributed vibration on a flat surface.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.816-820
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• 2003

The objective of this paper is to develop an experimental technique to measure the in-plane vibration intensity of a plate. In order to measure the in-plane vibration intensity at a data point, the frequency response functions for the 2 components of an acceleration vector are measured at each point of 4 points in the neighborhood of the data point. This experimental technique has been implemented to measure the in-plane vibration intensity of a plate. The experimental result has been compared with a theoretical result. It showed that the experimental technique can be effectively used to measure the in-plane vibration intensity of plates.

• 동력기계공학회지
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• 제11권4호
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• pp.78-85
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• 2007

In order to analyze accurately the vibration of a structure by using the finite element method (FEM), we have to model a analytical structure as a numerical model with many degrees-of-freedom. However, in this case, the FEM needs much computation time and storage. The authors developed the finite element-transfer stiffness coefficient method (FE-TSCM) for overcoming the drawback of the FEM. In this paper, the authors apply the FE-TSCM to the in-plane vibration analysis of general plates with various shapes. Two numerical examples, a rectangular plate and a triangular plate, are used to compare the results of the FE-TSCM and the FEM. Through the numerical calculation, we confirm that the FE-TSCM can be applied to the in-plane free or forced vibration analysis of the general plates with various shapes and is effective to in-plane vibration analysis of general plates.

• 한국소음진동공학회논문집
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• 제11권6호
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• pp.181-192
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• 2001

The power flow analysis (PFA) has been performed to analyze the vibration of coupled plates excited by a point force in an arbitrary direction. The point force generates the out-of-plane vibration associated wish flexural waves and the in-plane vibration associated with longitudinal and shear waves. The energy governing equation for each type of waves was introduced and solved to Predict the vibrational energy density and intensity generated by the out-of-plane and in-plane components of the point force in an arbitrary direction. The wave transmission approach was used to consider the mode conversion at the joint of the coupled plates. Numerical results for vibrational energy density and intensity on the coupled plates were presented. Comparison of the results by PFA with exact results showed that PFA can be an effective tool to predict the spatial variation of the vibrational energy and intensity on the coupled plates at high frequencies.

• 전산구조공학
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• 제11권4호
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• pp.287-294
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• 1998

입면의 형태가 임의의 층에서 큰 차이를 보이는 3차원 비정형 setback 구조물의 동적 거동 특성과 이들 구조물의 동적 거동에 미치는 바닥 슬래브의 면내 변형 효과를 분석하였다. 비정형 setback 구조물의 전반적인 동적 거동특성을 분석하기 위하여 베이스 부분의 평면적과 타워 부분의 평면적 비(R?), setback 발생위치(L?)등을 매개 변수로 사용하였다. 48개의 비정형 setback 구조물들에 대한 해석 수행 결과 setback 구조물은 정형 구조물에 비해 횡방향 1차 모드의 유효 모드 중량(effective modal weight)이 작게 나타나는 경향을 보이기 때문에 setback 구조물의 동적 거동을 파악하기 위해서는 등가 정적 해석법 대신에 동적 해석을 수행할 필요가 있음을 알 수 있었다. 바닥슬래브의 면내 변형은 보다 긴 구조물의 고유 진동 주기값을 가져오며 모드 순서 및 모드 형상에도 변화를 준다. 이러한 사실은 바닥슬래브의 면내 변형으로 인하여 횡방향 저항 요소들간의 전단력 분포와 층 변위가 영향을 받을 수 있다는 것을 의미한다. 이러한 현상은 횡방향 저항 요소들간의 강성 차가 심한 프레임-전단벽 시스템에서 두드러지게 나타난다.

• 대한기계학회논문집A
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• 제27권1호
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• pp.42-47
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• 2003

Nonlinear models for a thin ring rotating at a constant speed are developed. The geometric nonlinearity of displacements is considered by adopting the Lagrange strain theory for the circumferential strain. By using Hamilton’s principle, the coupled nonlinear partial differential equations are derived, which describe the out-of-plane and in-plane bending, extensional and torsional motions. The natural frequencies are calculated from the linearized equations at various rotational speeds. Finally, the computation results from the nonlinear models are compared with those from a linear model. Based on the comparison, this study recommends which model is appropriate to describe the behavior of the rotating ring.