• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.10
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• pp.1900-1907
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• 1992

This paper presents the vibration mode, natural frequencies and amplitudes of the circular plate due to the changes of the boundary conditions by varying free arc angles. The vibration mode, amplitudes and natural frequencies of the circular plate are obtained by time-average holographic interferometry and laser doppler vibrometer. The vibration modes of the circular plate with the mixed boundary conditions are found from the 1st mode to the 4th mode. The curve shapes of the natural frequency ratios obtained from this study are in a good agreement with other results obtained by numerical analysis. The displacement curves obtained from time average holographic interferometry and laser doppler vibrometer agree well in case of large amplitude, but show a little difference in case of small amplitude.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.908-913
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• 2002

An analytical study is presented on the hydroelastic vibration of two rectangular identical plates coupled with a bounded fluid by using the finite Fourier series expansion method. It is observed that the two contrastive modes, the so called the out-of-phase and in-phase modes appear. The proposed analytical method is verified by observing a good agreement to three dimensional finite element analysis results. All natural frequency of the in-phase modes can be predicted well by the combination of the dry beam modes. The theoretical prediction for the out-of-phase mode can be improved by using the polynomial functions satisfying the plate boundary conditions and fluid volume conservation instead of using dry beam modes.

• Computational Structural Engineering
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• v.3 no.2
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• pp.77-88
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• 1990

Two perforated plates (a square plate and a rectangular plate having an aspect ratio 1.57(L/sub x/=11, L/sub y/=7)) are taken as analysis examples. Each of these plates is given some changes in the boundary conditions. The size of cutouts as well as their locations are also changed in order to examine the variation of two eigenvalues corresponding to the fundamental mode. The relationship between two eigenvalues is established by changing the magnitude of edge thrust.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.6
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• pp.674-680
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• 2008

A new meshless method for obtaining natural frequencies of arbitrarily shaped plates with the free boundary condition is introduced in the paper. In order to improve the characteristics of convergence and accuracy of the method, a special local polar coordinates system is devised and located for each of nodes distributed along the boundary of the plate of interest. In addition, a new way of decreasing the size of the system matrix that gives natural frequencies of the plate is employed to reduce the amount of numerical calculations, which is needed for computing the determinant of the system matrix. Finally the excellence of the characteristics of convergence and accuracy of the method is shown in several case studies, which indicate that natural frequencies by the proposed method are very accurate and converged swiftly to exact values as the number of boundary nodes increases.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.4
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• pp.313-320
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• 1991

The paper describes the formulation for the analysis of the flexural free vibration of rectangular plate structure by the transfer influence coefficient method, which was developed on the base of the concept of the successive transmission of dynamic influence coefficients. For the analysis of rectangular plate which two opposite sides are simply-supported edge condition, the results of simple numerical examples demonstrate the validity of the present method, that is, the numerical high accuracy, the high speed and the flexibility for programming, compared with results of the transfer matrix method and exact solution or Leissa's method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.11
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• pp.779-786
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• 2015

The Kansa method, which is used for various free vibration problems of arbitrarily shaped plates including membranes, discretizes the domain of a plate using only nodes without elements unlike FEM. The method requires a small amount of computation relative to FEM thanks to this discretization scheme but has limit in the accuracy of its solution. This paper reveals the reason of the limit and, to overcome the limit, proposes the practical method of calculating the singularity of a system matrix and extracting accurate natural frequencies. Case studies for a rectangular plate and an arbitrarily shaped plate validate the proposed method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.4
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• pp.336-343
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• 2004

This paper reports the first known free vibration data for thin rectangular plates with V-notches. The classical Ritz method is employed with two sets of admissible functions assumed for the transverse vibratory displacements. These sets include (1) mathematically complete algebraic-trigonometric polynomials which guarantee convergence to exact frequencies as sufficient terms are retained, and (2) corner functions which account for the bending moment singularities at the sharp reentrant corner of the Y-notch. Extensive convergence studies summarized herein confirm that the corner functions substantially enhance the convergence and accuracy of nondirectional frequencies for rectangular plates having the V-notch. In this paper, accurate frequencies and normalized contours of vibratory transverse displacement are presented for various notched plates, so that the effect of corner stress singularities may be understood.

• Journal of KSNVE
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• v.10 no.2
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• pp.312-318
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• 2000

A modeling method for the vibration analysis of rotating cantilever plastes with stiffeners is presented. The equations of motion for the plates aer derived and trnasformed into a dimensionless form. A mass density Dirac's delta function is used to idealize the stiffener mathematically. The effects of stiffeners on the model characteristics of the plate are investigated, and mode shape variations due to some parameter variation are exhibited. It is found that veering phenomena occur between some loci and associated mode shapes change significantly during the veering phenomena.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.743-747
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• 2003

In recent years, several studies of the practical application of active sound and vibration control have been developed to plate to plate response with various boundary conditions. This study considers vibration and sound radiation for the clamped rectangular plate. The radiation of a sound from rectangular plate can be calculated that the velocity of a vibrating plate is analyzed. The vibration formulation is based on a variation method for the vibration of the plate, and assumes no damping, no fluid loading of the structure. And the plate is exited by harmonic point force. The radiation of sound from plate is analyzed in the far field, and is calculated from the Rayleigh integral. The prediction results of vibration and sound level have proved with FEM or BEM.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.833-839
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• 2003

The effects of stiffeners on the modal characteristics of rectangular plates are investigated. A modeling method for the modal analysis of rectangular plates with stiffeners is presented. A mass density Dirac's delta function is used to idealize the stiffeners mathematically. The equations of motion for the plates are derived and transformed into a dimensionless form. To confirm the accuracy of the method presented in this study, numerical result are obtained and compared to those of a commercial program. The mode shape variations due to some parameter variations are also exhibited.