• Title/Summary/Keyword: Vibration Transfer

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A Study on the Analysis Algorithm of Time Historical Response of Straight-line Structure by the Transfer Stiffness Coefficient Method (전달강성계수법에 의한 직선형 구조물의 시간 이력응답 해석알고리즘에 관한 연구)

  • Moon, D.H.;Kang, H.S.;Choi, M.S.
    • Journal of Power System Engineering
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    • v.3 no.1
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    • pp.74-79
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    • 1999
  • This paper describes formulation for algorithm of time historical response analysis of vibration for straight-line structure. This method is derived from a combination of the transfer stiffness coefficient method and the Newmark method. And this present method improves the computational accuracy of the transient vibration response analysis remarkably owing to several advantages of the transfer stiffness coefficient method. We regarded the structure as a lumped mass system here. The analysis algorithm for the time historical response was formulated for the straight-line structure containing crooked, tree type system. The validity of the present method compared with the transfer matrix method and the Finite Element Method for transient vibration analysis is demonstrated through the numerical computations.

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Forced vibration analysis of beam-like structures by the combination and transfer of dynamic stiffness coefficient (동강성계수의 조합 및 전달에 의한 보형 구조물의 강제진동 해석)

  • 문덕홍;최명수
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.1
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    • pp.21-27
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    • 1998
  • The authors have developed the transfer dynamic stiffness coefficient method(TDSCM) which is based on the concepts of the substructure synthesis method and transfer influence coefficient method. As a result, we suggested the algorithm for free vibration analysis of beam-like structures which are mainly found in mechanical design by applying the TDSCM in the previous reports. In this paper, we extend this algorithm to the forced vibration analysis for them. And we also confirmed the merits of this method.

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Experimental Study on Effect of Boiling Heat Transfer by Ultrasonic Vibration (초음파 진동이 비등열전달 과정에 미치는 영향에 관한 실험적 연구)

  • Na Gee-Dae;Oh Yool-Kwon;Yang Ho-Dong
    • Journal of Energy Engineering
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    • v.15 no.1 s.45
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    • pp.35-44
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    • 2006
  • This study experimentally investigates effect of boiling heat transfer when ultrasonic vibration was applied. Under the wall temperature condition, temperature distribution in a cavity was measured during the boiling process and heat transfer coefficient of convection, sub-tooled boiling and saturated boiling states were measured with and without ultrasonic vibration, respectively. Also, the profiles of the pressure distribution in acoustic field measured by a hydrophone were compared with the augmentation ratios of heat transfer calculated by local heat transfer coefficient. Result of this study, heat transfer coefficient and augmentation ratio of heat transfer is higher with ultrasonic waves than without one. Especially, augmentation ratio of heat transfer is more increased the convection state than sub-cooled boiling and saturated boiling states. Acoustic pressure is relatively higher near ultrasonic transducer than other points where is no installed it and affects the augmentation ratio of heat transfer.

On Development of Vibration Analysis Algorithm of Beam with Multi-Joints (다관절 보의 진동해석 알고리즘의 개발에 관한 연구)

  • 문덕홍;여동준;최명수
    • Journal of Advanced Marine Engineering and Technology
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    • v.18 no.5
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    • pp.68-77
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    • 1994
  • The authors apply the transfer influence coefficient method to the 3-dimensional vibration analysis of beam with multi-joints and formulate a general algorithm to analysis the longitudinal, flexural and torsional coupled free vibration. In this paper, the structure, which is mainly founded in the robot arms, cranes and so on, has some crooked parts, subsystems and joints but has no closed loop in this system. It is modeled as the beam of a distributed mass system with massless translational, rotational and torsional springs in each node, and joint elements of release or roll at which node the displacement vector is discontinuous. The superiorty of the present method to the transfer matrix method in the computation accuracy was confirmed by the numerical computation results. Moreover, we confirmed that boundary and intermediate conditions could ve controlled by varying the values o the spring constants.

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On Development of Vibrational Analysis Algorithm of Cylindrical Shell Structures With Stiffeners (보강재를 갖는 원통셸 구조물의 진동해석 알고리즘의 개발에 관한 연구)

  • 문덕홍;여동준
    • Journal of KSNVE
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    • v.6 no.4
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    • pp.481-491
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    • 1996
  • In this paper, we formulated algorithm for free vibration analysis of cylindrical shells with stiffeners by applying the transfer influence coefficient method. This was developed as a vibration analysis method suitable for using personal computer(PC). The simple computational results form PC demonstrated the validity of the present algorithm, that is, the computational high accuracy and speed, and the flexibility of programming. We compared with results of the transfer matrix method and the reference. We also confirmed that the present algorithm could provide the solutions of high accuracy for system with a lots of intermediate rigid supports and stiffeners. And all boundary conditions and the intermediate stiff supports between shell and foundation could be treated only by adequately varying the values of the spring constants.

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Deflection Limit on Vibration Serviceability of High-speed Railway Bridges Considering the Exposed Time Duration (진동지속시간을 고려한 고속철도교량의 진동 사용성 처짐 한계)

  • Jeon, Bub-Gyu;Kim, Nam-Sik;Kim, Sung-Il
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1444-1451
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    • 2010
  • This paper aims for proposed the deflection limit on vibration serviceability of high-speed railway bridges considering the exposed time duration when a train passes a railway bridge. For this purpose, bridge-train transfer function was derived and bridge-train interaction analysis was performed by using the derived function. The vertical acceleration signals of passenger cars obtained from bridge-train interaction analysis were compared with them from the bridge-train transfer function by moving constant force analysis. Therefore it was estimated possible to induce the comfort deflection limit of railway bridge by using bridge-train transfer function. The deflections by moving force of single span bridge and continuous bridge were assumed as sine and haversine wave. The deflection limit on vibration serviceability of high-speed railway bridges considering the exposed time duration can be expanded using bridge-train transfer function and bridge comfort limit considering serviceability due to bridge vibration. And it was compared to other allowable deflection limits of railway bridge design specifications.

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Free Vibration Analysis of Axisymmetric Cylindrical Shell by Sylvester-Transfer Stiffness Coefficient Method (실베스터-전달강성계수법에 의한 축대칭 원통형 셸의 자유진동 해석)

  • Choi, Myung-Soo;Yeo, Dong-Jun
    • Journal of Power System Engineering
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    • v.17 no.2
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    • pp.46-55
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    • 2013
  • In this paper, the computational algorithm for free vibration analysis of an axisymmetric cylindrical shell is formulated by the Sylvester-transfer stiffness coefficient method (S-TSCM) which combines the Sylvester's inertia theorem and the transfer stiffness coefficient method. After the computational programs for obtaining the natural frequencies and natural modes of the axisymmetric cylindrical shell are made by the S-TSCM and the finite element method (FEM), the computational results which are natural frequencies, natural modes, and computational times by both methods are compared. From the computational results, we can confirm that S-TSCM has the reliability in the free vibration analysis of the axisymmetric cylindrical shell and is superior to FEM in the viewpoint of computational times.

Free Vibration Analysis of Lattice Type Structures by the Combination and Transfer of Stiffness Coefficient (강성계수의 조합 및 전달에 의한 격자형 구조물의 자유진동 해석)

  • 문덕홍;최명수;강화중;강현석
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.169-175
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    • 1997
  • Recently it is increased by degrees to produce complex and large lattice structures such as bridge, tower, crane, and space structures. In general, in order to analyse these structures we have used finite element method(FEM). In this method, however, it is necessary to use a large amount of computer memory and to take long computation time. For overcoming this problem, the Authors have developed the transfer dynamic stiffness coefficient method(TDSCM) which consists on the concept of the substructure synthesis method and transfer influence coefficient method. In this paper, the new free vibration analysis method for large type lattice structure is formulated by the TDSCM. And the results obtained by TDSCM are compared with those obtained by FEM, transfer matrix method and experiment. And it is confirmed for TDSCM to be the numerical high accuracy and high speed structure analysis method.

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Vibration Analysis of Expansion Joint based on Transfer Matrix Method Considering the Rotary Inertia (회전 관성을 고려한 전달행렬법 기반의 Expansion Joint 진동해석)

  • Shin, Dong-Ho;Kim, Sang-Ho;Yoon, Hyung-Ho;Lim, Hee-Gon;Oh, Jae-Eung;Lee, Jung-Youn
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.7
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    • pp.665-673
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    • 2011
  • Simplified formulae for axial and bending natural frequencies of a bellows are developed using an equivalent thin-walled pipe model. The axial and bending stiffness of bellows is determined using lumped transfer matrix method. Transfer matrix method which includes the rotary inertia is used to calculate the natural frequencies for axial and lateral vibration. The result from the simplified formula are verified by those from as experiment result and a finite element analysis. This comparisons show good agreement with the each other.

Vibration Analysis for a Complex and Large Lattice Type Structure Using Transfer Dynamic Stiffness Coefficient (동강계수의 전달에 의한 복잡 거대한 격자형 구조물의 진동해석)

  • 문덕홍;최명수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.10a
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    • pp.190-195
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    • 1997
  • Recently it is increased by degrees to construct complex or large lattice type structures such as bridges, towers, cranes, and structures that can be used for space technology. In general, in order to analyze, these structures we have used the finite element method(FEM). In this method, however, it is necessary to use a large amount of computer memory and computation time because the FEM requires many degrees of freedom for solving dynamic problems for these structures. For overcoming this problem, the authors have developed the transfer dynamic stiffness coefficient method(TDSCM). This method is based on the concepts of the transfer and the synthesis of the dynamic stiffness coefficient which is related to force and displacement vector at each node. In this paper, the authors formulate vibration analysis algorithm for a complex and large lattice type structure using the transfer of the dynamic stiffness coefficient. And the validity of TDSCM demonstrated through numerical computational and experimental results.

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