• Journal of KSNVE
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• v.9 no.1
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• pp.149-162
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• 1999

A method for the analysis of free vibrations of steel and plain weave composite cylindrical shells with a longitudinal, interior rectangular plate is developed by using the receptance method. This method is based on the ratio of a deflection (or slope) response to a harmonic force(or moment) at the joint. In this study, after getting the free vibration characteristics of the simply supported plate and shell, the frequency equation of the combined system is obtained by considering the continuity condition at the joint between the plate and the shell. The numerical results are compared with published results and experiment results in order to show the validate of the formulation, and shown that the analytical results agreed with those from other methods. The effects of the location and the thickness of the plate on the natural frequencies are also investigated.

• Journal of KSNVE
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• v.8 no.4
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• pp.616-622
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• 1998

An analytical method has been developed to estimate the dynamic contact force between wheel and rail when trains are running on rail with vertical irregularities. In this method, the effect of Hertzian deformation at the contact point is considered as a linearized spring and the wheel is considered as an sprung mass. The rail is modelled as a discretely-supported Timoshenko beam, and the periodic structure theory was adopted to obtain the driving-point receptance. As an example, the dynamic contact force for a typical wheel/rail system was analysed by the method developed in this research and the dynamic characteristics of the system was also discussed. It is revealed that discretely-supported Timoshenko beam model should be used instead of the previously used continuously-supported model or discretelysupported Euler beam model, for the frequency range above several hundred hertz.

• Selected Papers of The Society of Naval Architects of Korea
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• v.1 no.1
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• pp.52-64
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• 1993

There exist many frame structural systems having some attachments reducible to damped spring-mass systems, concentracted masses and spring supports. For free and forced vibration analyses of such a system an analytical method based on the receptance method is presented. A framed structure having attachments is considered as a combined system composed of various Timoshenko beam and bar elements and the attachments. So, the vibration characteristics of the system are calculated by synthesizing receptances and Support Displacement Transfer Ratio (SDTR) of beam and bar elements In spectral and/or closed forms, and receptances of the attachments. In forced vibration analysis, arbitrary excitation forces at a point on the structure and displacement excitations at boundaries are considered. Numerical investigations are carried out for verification of the presented method, and the results show good accuracy and very high computational efficiency.

• Journal of KSNVE
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• v.10 no.3
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• pp.444-450
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• 2000

Wheel-rail noise is normally classified into three catagories : rolling impact and squeal noise. In this paper rolling noise caused by the irregularity between a wheel and a rail is analysed as follows: The irregularity between the wheel and the rail is assumed as linear superposition of sinusoidal profiles. Wheel-rail contact stiffness is linearized by using Hertzian contact theory and then contact force between the wheel and the rail is calculated. vibration of the rail and the wheel is calculated theoretically by receptance method or FEM depending on the geometry of the wheel or the rail for the frequency range of 100-500 Hz important for noise generation. The radiation noise caused by those vibration response is computed by BEM To verify this analysis tools rolling noise is calculated by proposed analysis steps using typical roughness data and these results are compared with experimental rolling noise data. This analysis tools show reasonable results and finally used for the prediction of the Korean high speed train rolling noise.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.2
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• pp.63-77
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• 1990

The combined deckstructure-car system of a car carrier is especially sensitive to hull girder vibrations due to mechanical excitations and wave loads. For the free and forced vibration analysis of the system, the analytical methods based on the receptance method and two schemes for efficient applications of the methods are presented. The methods are especially relevant to dynamical reanalysis of the system subject to design modification or to dynamic optimization. The deck-car system is modelled as a combined system consisting of a stiffened plate representing deck, primary structure, and attached subsystems such as pillars, additional stiffeners and damped spring-mass systems representing cars/trucks. For response calculations of the system subjected to displacement excitations along the boundaries, the support displacement transfer ratio conceptually similar to the receptance is introduced. For the verification of accuracy and calculation efficiency of the proposed methods, numerical and experimental investigations are carried out.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.353.1-353
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• 2002

Impulse response of a slightly asymmetric cylindrical shell is derived. Receptance method is applied to obtain the vibration mode and natural frequency of the slightly asymmetric cylindrical shell. Impulse response model is used to identify the vibration beat characteristics of King Song-Dok Bell. The theretical mode is compared and verified by the measured mode of King Song-Dok Bell. (omitted)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.1027-1031
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• 2000

In this paper, multiphase dynamic optimization of machine structure is presented. The final goal is to obtain ( i ) light weight, and ( ii ) rigidity statically and dynamically. The entire optimization process is carried out in two steps. In the first step, multiple optimization problem with two objective functions is treated using Pareto genetic algorithm. Two objective functions are weight of the structure, and static compliance. In the second step, maximum receptance is minimized using genetic algorithm. The method is applied to a simplified milling machine.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.10a
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• pp.151-156
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• 1993

본 논문에서는 탄성바닥 위에서의 세개의 질량과 두개의 방지재로 구성된 지지계에 의한 진동절연의 이론적 고찰과 실험에 의한 검증을 하였다. 효과 적인 진동절연은 본 논문에서 기본적으로 관심을 가지는 탄성바닥에서의 진 동전달률을 감소시키는 것이며, 단순한 수학적 형태로 표현되는 진동전달률 공식은 영향계수법(Receptance Method)을 이용하여 유도된다.

• Smart Structures and Systems
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• v.9 no.1
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• pp.55-70
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• 2012

It is not easy to experimentally obtain the FRF (Frequency Response Function) matrix corresponding to a full set of DOFs (degrees of freedom) for a dynamic system. Utilizing FRF data measured at specific positions, with DOFs less than that of the system, as constraints to describe a damaged system, this study identifies parameter matrices such as mass, stiffness and damping matrices of the system, and provides a damage identification method from their variations. The proposed parameter identification method is compared to Lee and Kim's method and Fritzen's method. The validity of the proposed damage identification method is illustrated in a simple dynamic system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.2
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• pp.97-107
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• 2002

The continuous circular cylindrical shells are widely used for the high performance structures of aircraft, spacecraft, missile, nuclear fuel rod shell and so on. In this paper, a method for the vibrational analysis of the continuous circular cylindrical shells with the clamped-clamped supports at two end edges is developed by using the modal expansion method. Forces and/or moments acting on the shell surface are expressed in terms of the Dirac Delta Function. Frequency equation of the continuous shell is also derided by the application of the equilibrium of forces and the continuity of displacements at the boundary. Natural frequencies of the continuous shell are calculated numerically with mathematica 3.0 and they are compared with FEM results from the ANSYS 5.3 to improve the reliability of analytic solutions. Mode shares obtained by the FEM are Presented in this paper.