• Title/Summary/Keyword: Sylvester's Inertia Theorem

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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.

Flexural Free Vibration Analysis of Axisymmetric Annular Plates Using Sylvester-Transfer Stiffness Coefficient Method (실베스터-전달강성계수법을 이용한 축대칭 환원판의 굽힘 자유진동 해석)

  • Choi, Myung-Soo;Kondou, Takahiro;Byun, Jung-Hwan;Yeo, Dong-Jun
    • Journal of Power System Engineering
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    • v.19 no.6
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    • pp.60-67
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    • 2015
  • While designing and operating machines, it is very important to understand the dynamic characteristic of the machines. Authors developed the Sylvester-transfer stiffness coefficient method in order to analyze effectively the free vibration of machines or structures. The Sylvester-transfer stiffness coefficient method was derived from the combination of the Sylvester's inertia theorem and the transfer stiffness coefficient method. In this paper, the authors formulate the computational algorithm for flexural free vibration analysis of axisymmetric annular plate using the Sylvester-transfer stiffness coefficient method. To confirm the usefulness of the Sylvester-transfer stiffness coefficient method, the natural frequencies and modes for two computational models computed using the Sylvester-transfer stiffness coefficient method are compared with those computed using the exact solution and the finite element method.

Free Vibration Analysis of Axisymmetric Conical Shell

  • Choi, Myung-Soo;Yeo, Dong-Jun;Kondou, Takahiro
    • Journal of Power System Engineering
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    • v.20 no.2
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    • pp.5-16
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    • 2016
  • Generally, methods using transfer techniques, like the transfer matrix method and the transfer stiffness coefficient method, find natural frequencies using the sign change of frequency determinants in searching frequency region. However, these methods may omit some natural frequencies when the initial frequency interval is large. The Sylvester-transfer stiffness coefficient method ("S-TSCM") can always obtain all natural frequencies in the searching frequency region even though the initial frequency interval is large. Because the S-TSCM obtain natural frequencies using the number of natural frequencies existing under a searching frequency. In this paper, the algorithm for the free vibration analysis of axisymmetric conical shells was formulated with S-TSCM. The effectiveness of S-TSCM was verified by comparing numerical results of S-TSCM with those of other methods when analyzing free vibration in two computational models: a truncated conical shell and a complete (not truncated) conical shell.