• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1587-1600
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• 1991

본 연구에서는 로봇조작기를 강체부와 유연한 외팔보로 이루어진 모델로 설정 한 후 확장된 Hamilton의 원리를 적용하여 제어계의 운동방정식을 유도하였다. 계를 유한개의 제어 모드와 잔류 모드로 구분하고, 제어 모드에 대해 최적제어를 수행하기 위해 관측기를 설계하였으며, 진동에 관련된 측정 불가능한 상태변수를 추정하였다. 분석과 검토는 서보모터가 모든 제어를 담당하는 방식과 서보모터의 제어 방식에 작동 기를 추가시켜 병행 제어하는 다입출력 방식으로 구별하여 수행하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.514-520
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• 2002

A new non-linear modelling of a straight pipe conveying fluid is presented for vibration analysis when the pipe is fixed at both ends. Using the Euler-Bernoulli beam theory and the non-linear Lagrange strain theory, from the extended Hamilton's principle are derived the coupled non-linear equations of motion for the longitudinal and transverse displacements. These equations of motion are discretized by using the Galerkin method. After the discretized equations are linearized in the neighbourhood of the equilibrium position, the natural frequencies are computed from the linearized equations. On the other hand, the time histories for the displacements are also obtained by applying the generalized-$\alpha$ time integration method to the non-linear discretized equations. The validity of the new modelling is provided by comparing results from the proposed non-linear equations with those from the equations proposed by Paidoussis.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.372-377
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• 2001

A new non-linear of a straight pipe conveying fluid is presented for vibration analysis when the pipe is fixed at both ends. Using the Euler-Bernoulli beam theory and the non-linear Lagrange strain theory, from the extended Hamilton's principle are derived the coupled non-linear equations of motion for the longitudinal and transverse displacements. These equations of motion for are discretized by using the Galerkin method. After the discretized equations are linearized in the neighbourhood of the equilibrium position, the natural frequencies are computed from the linearized equations. On the other hand, the time histories for the displacements are also obtained by applying the $generalized-{\alpha}$ time integration method to the non-linear discretized equations. The validity of the new modeling is provided by comparing results from the proposed non-linear equations with those from the equations proposed by $Pa{\ddot{i}}dousis$.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.4
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• pp.39-45
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• 1995

본 논문은 복수 집중질량을 갖고 제어 종동력을 받는 자유 Timoshenko보의 동적 안정성에 관한 것으로, 비행중의 미사일이나 로켓의 연료탱크, Payload등의 기계장치부를 복수의 집중질량으로 간주하여 이러한 항공우주 구조물들이 추진력인 종동력을 받을때에 대한 계의 동적 안정성을 판별한다. 수학적 모델에 대한 운동방정식은 확장된 해밀톤 원리를 이용한 유한요소법에 의해 유도되며, 복수 부가질량의 위치 및 크기변화, 센서의 위치 및 게인(gain)의 변화에 따른 계의 안정성 지도(stability maps)를 보여준다. 또한 보의 전단 변형이나 회전관성의 효과 뿐만아니라, 추질력의 방향이 제어되는 경우와 제어되지 않는 경우에 대한 최대 추진력 값이 수치 시뮬레이션을 통해 예측된다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.4
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• pp.27-34
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• 2005

The paper discussed on the stability of cantilevered pipe conveying fluid subjected to distributed follower force. Governing equations of motion are derived by extended Hamilton's principle, and the numerical scheme using finite element method is applied to obtain the discretized equations. The critical flow velocity as a function of the distributed follower force for the various mass ratio is determined. The flutter configurations of the pipes at the critical flow velocities are drawn graphically at every twelfth period to define the order of quasi-mode of flutter configuration The critical mass ratios, at which the transference of the eigenvalue branches related to flutter take place, are definitely determined. Also, the effect of damping on the stability of the system is considered.