• Journal of Mechanical Science and Technology
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• 제20권2호
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• pp.191-196
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• 2006

This paper presents the application of techniques of differential transformation method (DTM) to analyze the transverse vibration of a uniform Euler-Bernoulli beam under varying axial force. The governing differential equation of the transverse vibration of a uniform Euler-Bernoulli beam under varying axial force is derived and verified. The varying axial force was extended to the more general case which was high polynomial consisted of many terms. The concepts of DTM were briefly introduced. Numerical calculations are carried out and compared with previous published results. The accuracy and the convergence in solving the problem by DTM are discussed.

• 대한기계학회논문집A
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• 제33권12호
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• pp.1410-1416
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• 2009

In this paper, the purpose is to investigate the stability and variation of natural frequency of a cracked cantilever beams subjected to follower force and tip mass. In addition, an analysis of the flutter instability(flutter critical follower force) of a cracked cantilever beam as slenderness ratio and crack severity is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force is derived via Hamilton's principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. Finally, the influence of the slenderness ratio and crack severity on the critical follower force, stability and the natural frequency of a beam are investigated.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.575-578
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• 2008

In this paper, the purpose is to investigate the stability and variation of natural frequency of a Timoshenko cantilever beam subjected to follower force and tip mass. In addition, an analysis of the flutter instability(flutter critical follower force) of a cantilever beam as slenderness ratio is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force is derived via Hamilton;s principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. Finally, the influence of the slenderness ratio and tip mass on the critical follower force and the natural frequency of a Timoshenko beam are investigated.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.961-966
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• 2008

In this paper, the purpose is to investigate the stability and variation of natural frequency of a Timoshenko cantilever beam subjected to Subtangential follower force and tip mass. In addition, an analysis of the flutter instability(flutter critical follower force) of a cantilever beam as slenderness ratio is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force is derived via Hamilton;s principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. Finally, the influence of the slenderness ratio and tip mass on the critical follower force and the natural frequency of a Timoshenko beam are investigated.

• 대한기계학회논문집B
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• 제20권6호
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• pp.2005-2013
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• 1996

Particle paths and flow fields in a prototype differential mobility analyzer (DMA) were numerically analyzed solving Navier-Stokes equation, electric field equation and particle motion considering viscous drag force, Coulomb force and polarization force. Analytically predicted particle diameters for the prototype DMA are in good agreement with the measured particle diameters within $\pm$1%. And the analytically predicted particle diameters are also in good agreement with numerical results for the prototype DMA.

• 대한기계학회논문집A
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• 제31권2호
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• pp.231-236
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• 2007

This paper presents the effect of the center of the series on convergence in solving vibration problems by Differential Transformation Method(DTM) to the transverse vibration of the Euler-Bernoulli beam under varying axial force. The governing differential equation of the transverse vibration of the Euler-Bernoulli beam under varying axial force is derived. The concepts of DTM were briefly introduced. Numerical calculations are carried out and compared with previously published results. The effect of the center of the series on convergence in solving the problem by DTM is discussed.

• 한국농공학회지
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• 제34권1호
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• pp.57-65
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• 1992

The main purpose of this paper is to present both the natural frequencies and mode shapes of tapered beams under tensile axial force. The differential equation governing planar free vibration for tapered beams under tensile axial force is derived as nondimensional form. The three kinds of cross sectional shape are considered in differential equation. The Runge-Kutta method and Determinant Search method are used to perform the integration of the differential equation and to determine the natural frequencies, respectively. The hinged-hinged, hinged-clamped, clamped-clamped and constraints are applied in numerical examples. The lowest four nondimensional natural frequencies are reported as the function of nondimensional tensile axial force. The fundamental natural frequencies are presented when section ratios and nondimensional axial forces are varied. The effects of cross sectional shapes are reported and some typical mode shapes are also presented.

• 한국정밀공학회지
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• 제26권9호
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• pp.112-120
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• 2009

In this paper the purpose is to investigate the stability and variation of natural frequency of a cracked Timoshenko cantilever beams subjected to subtangential follower force. In addition, an analysis of the stability of a cantilever beam as the crack effect and slenderness ratio is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force are derived via Hamilton's principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. By using the results of this paper, we can obtain the judgment base that the choice of beam models for the effect of slenderness ratio and crack.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.433-434
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• 2006

The limited slip differential(LSD) is a device which enables the driving force to be transmitted from one slipping wheel to another wheel in such case that the car is stuck in clay or snow. When the unwanted slipping occurs on one wheel, the LSD temporarily restraints the differential motion to transmit the driving force in the other wheel. So far, many types of LSD were developed such as mechanical lock type, disk clutch type, viscous coupling type, torsion type and multiple clutch type. we designed a new type of the hydraulic LSD which uses the principle of trochoid gear pump.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1018-1023
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• 2005

A new MR cylinder with built-in valves using MR fluid (MR valve) is suggested and fabricated for fluid control systems. The MR fluid is a newly developed functional fluid whose obvious viscosity is controlled by the applied magnetic field intensity. The MR cylinder is composed of cylinder with small clearance and piston with electromagnet. The differential pressure is controlled by the applied magnetic field intensity. It has the characteristics of simple, compact and reliable structure. The size of MR cylinder and piston has ${\varphi}30mm{\times}300mm\;and\;{\varphi}28.5mm{\times}120mm$ in face size, respectively and 0.8mm in gap length. Through experiments, it was found that the differential pressure is controlled by the applied magnetic field intensity under little influence of the flow rate, which corresponds to a pressure control valve. The differential pressure of 0.47MPa and contact force of 320N were obtained with the input current of 1.5A. The rising time of force was 1.1s in step response of a manipulator using the MR cylinder. The effectiveness of the MR cylinder was also demonstrated through the force control.