• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.268-273
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• 2002

A modeling method for the dynamic characteristic analysis of a translationally accelerated trapezoidal cantilever plate is presented in this paper. The equations of motion for the plate are derived and transformed into a dimensionless form. The effects of the inclination angles and the acceleration on the vibration characteristics of the plate are investigated. Incidentally, natural frequency loci veering and associated mode shape variations are observed and discussed

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.2
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• pp.186-193
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• 2011

The NDIF method(non-dimensional dynamic influence function method) for free vibration analysis of arbitrarily shaped plates with the simply supported edge is newly developed in the paper. In order to extract the system matrix that gives the natural frequencies and natural modes of the plate of interest, the difficulty of measuring higher differential terms involved in the simply supported boundary condition is successfully overcome. Finally, the excellence of the characteristics of convergence and accuracy of the proposed method is shown through two verification examples, which indicate that natural frequencies and natural modes obtained by the proposed method are very accurate and swiftly converged even though a small number of nodes are used compared with FEM.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.613-618
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• 2000

It is well known that the rotating motion of a blade-like structure induces centrifugal inertia force that causes the variation of the natural frequencies of the structure. Even though most of blade-like structures can be successfully Idealized as beams, some behave like plates rather than beams. This paper presents a modeling method for the flapwise bending vibration analysis of rotating cantilever plates. The dependence of natural frequencies and free vibration modes on the angular speed as well as the aspect ratio of a rotating plate is investigated. Particularly. the natural frequency loci crossing is observed and discussed In the present study.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1331-1337
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• 2003

Linearized equations of motion for the vibration analysis of rotating cantilever plates with arbitrary orientation angle are derived in the present work. Two in-plane stretch variables are introduced to be approximated. The use of the two in-plane stretch variables enables one to derive the equations of motion which include proper motion-induced stiffness variation terms. The equations of motion are transformed into dimensionless forms in which dimensionless parameters are identified. The effects of the dimensionless parameters on the modal characteristics of rotating cantilever plates are investigated through numerical study. The natural frequency loci veering along with the associated mode shape variations, which occur while the rotating speed increases, are also presented and discussed.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.349-354
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• 2001

A structure which is accelerated in the chordwise direction induces variation of the bending stiffness due to inertia force. Thus, the characteristic of natural vibration is also changed. This paper presents a modeling method for the vibration analysis of translationally accelerated cantilever plates. The dependence of natural frequencies and modes on the acceleration changes of the plate is investigated. Particularly, a natural frequency loci veering is observed and discussed in the present study.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.43-49
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• 2002

In this Paper, the mechanical behavior of two reかangular plates spot-welded under free vibration is investigated in detail. The focus of the analysis is to evaluate the effect of thickness of reinforced plates with equivalent thickness. The results of this the investigation are compared with detailed finite element analysis end experiments of the plates spot-welded for various parameters, such as aspect ratio, arm ratio, and distance ratio of spot-welding Points. The conclusion obtained are as followed. 1. The effect thickness due to spot-weld is very large, such as 55% in comparison with area ratio of spot-welding joint is just 4.52%. 2 The effect of thickness with respect to the distance ratio is maximized when the distance ratio is 0.4.

• The Journal of the Acoustical Society of Korea
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• v.18 no.3
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• pp.73-78
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• 1999

The paper describes a theoretical study on the flexural vibration of an elastic flat bar with periodically nonuniform material properties. The approximate solution of the natura1 frequency and mode shape has been obtained using the perturbation technique for sinusoidal modulation of the flexural rigidify and mass density. The numerical solution obtained by using the finite element method verifies the trend of the approximate solution. It appears that distributed vibrations exist in the low modes, and this approach can be extended to the vibration analysis of the p1ate in the flat panel speaker.

• Journal of KSNVE
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• v.11 no.2
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• pp.323-328
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• 2001

The paper describes a theoretical study on the flexural vibration of an elastic rectangular plate with periodically nonuniform material properties. The approximate solution of the natural frequency and mode shape has been obtained using the perturbation technique for sinusoidal modulation of the flexural rigidity and mass density. It has been shown that distributed modes exist in the plate which Is a two-dimensional model of the flat panel speaker.

• Journal of KSNVE
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• v.8 no.6
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• pp.1130-1136
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• 1998

A modelling method for the vibration analysis of rotating cantilever plates with a concentrated mass is presented. The equations of motion for the rotating plates with a concentrated mass located in an arbitrary position are derived and transformed into a dimensionless form. For the mathematical modelling of the concentrated mass. a mass density Dirac delta function is used. The effects of concentrated mass and its location. angular speed. plate aspect ratio. and hub radius of the rotating plate on the natural frequencies are studied. Particularly. mode shape variations due to some parameter variations are investigated.

• Journal of KSNVE
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• v.6 no.6
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• pp.771-779
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• 1996

In this paper, double Fourier sine series is used as a modal displacement functions of a rectangular plate and applied to the free vibration analysis of a rectangular plate under various boundary conditions. The method of stationary potential energy is used to obtain the modal displacements of a plate. To enhance the flexibility of the double Fourier sine series, Lagrangian multipliers are utilized to match the geometric boundary conditions, and Stokes' transformation is used to handle the displacements that are not satisfied by the double Fourier sine series. The frequency parameters and mode shapes obtained by the present method are compared with those obtained by MSC/NASTRAN and other analysis.