• Title/Summary/Keyword: 미분구적법

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Vibration Analysis for Circular Arches with Variable Cross-section by using Differential Transformation and Generalized Differential Quadrature (미분변환법과 일반화 미분구적법을 이용한 가변단면 원호 아치의 진동 해석)

  • Shin, Young Jae;Kwon, Kyung Mun;Yun, Jong Hak;Yoo, Yeong Chan;Lee, Ju Hyung
    • Journal of Korean Society of Steel Construction
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    • v.16 no.1 s.68
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    • pp.81-89
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    • 2004
  • The vibration analysis of the circular arch as a member of a structure has been an important subject of mechanics due to its various applications to many industrial fields. In particular, circular arches with variable cross section are widely used to optimize the distribution of weight and strength and to satisfy special architectural and functional requirements. The Generalized Differential Quadrature Method (GDQM) and Differential Transformation Method (DTM) were recently proposed by Shu and Zou, respectively. In this study, GDQM and DTM were applied to the vibration analysis of circular arches with variable cross section. The governing equations of motion for circular arches with variable cross section were derived. The concepts of Differential Transformation and Generalized Differential Quadrature were briefly introduced. The non-dimensionless natural frequencies of circular arches with variable cross section were obtained for various boundary conditions. The results obtained using these methods were compared with those of previous works. GDQM and DTM showed fast convergence, accuracy, efficiency, and validity in solving the vibration problem of circular arches with variable cross section.

Stress Analysis of Helical Spring Using DQM (미분구적법을 이용한 핼리컬 스프링의 응력해석)

  • Ki-Jun Kang
    • Journal of the Korean Society of Safety
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    • v.16 no.4
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    • pp.208-212
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    • 2001
  • DQM(differential quadrature method) is applied to computation of two dimensional elasticity problems in helical spring. Elastic shear stresses in an axially loaded helical spring having rectangular and square cross sections are calculated. The results are compared with those obtained using the method of successive approximations. The differential quadrature method gives good accuracy even when only a limited number of grid points is used.

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Free Vibration Analysis of Curved Beams with Varying Cross-Section (단면적이 변하는 곡선보의 진동해석)

  • Kang, Ki-Jun;Kim, Young-Woo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.5
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    • pp.453-462
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    • 2009
  • The differential quadrature method(DQM) is applied to the free in-plane vibration analysis of circular curved beams with varying cross-section neglecting transverse shearing deformation. Natural frequencies are calculated for the beams with various opening angles and end conditions. Results obtained by the DQM are compared with available results by other methods in the literature. It is found that the DQM gives good accuracy even with a small number of grid points. In addition, the corrected results are given for the beams not previously presented for this problem.

Free Vibration Analysis of Compressive Tapered Members Resting on Elastic Foundation Using Differential Quadrature Method (미분구적법(DQM)을 이용한 탄성지반 위에 놓인 변단면 압축부재의 자유진동 해석)

  • 이병구;최규문;이태은;김무영
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.4
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    • pp.629-638
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    • 2002
  • This paper deals with the free vibration analysis of compressive tapered members resting on elastic foundation using the Differential Quadrature Method. Based on the differential equation subjected to the boundary conditions, adopted from the open literature, which governs the free vibrations of such member, this equation is applied to the Differential Quadrature Method. For computing natural frequencies, the numerical procedures are developed by QR Algorithm, in which the Chebyshev-Gauss-Lobatto method is used for choosing the grid points. The numerical methods developed herein for computing natural frequencies are programmed in FORTRAN code, and all solutions obtained in this study are quite agreed with those in the open literature.

In-Plane Inextensional and Extensional Vibration Analysis of Curved Beams Using DQM (미분구적법(DQM)을 이용한 곡선보의 내평면 비신장 및 신장 진동해석)

  • Kang, Ki-jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.11
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    • pp.8064-8073
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    • 2015
  • One of the efficient procedures for the solution of partial differential equations is the method of differential quadrature. This method has been applied to a large number of cases to circumvent the difficulties of the complex algorithms of programming for the computer, as well as excessive use of storage due to conditions of complex geometry and loading. In-plane vibrations of curved beams with inextensibility and extensibility of the arch axis are analyzed by the differential quadrature method (DQM). Fundamental frequencies are calculated for the member with various end conditions and opening angles. The results are compared with exact experimental and numerical results by other methods for cases in which they are available. The DQM gives good accuracy even when only a limited number of grid points is used, and new results according to diverse variation are also suggested.

Out-of-Plane Vibration Analysis of Curved Beams Considering Shear Deformation Using DQM (전단변형이론 및 미분구적법을 이용한 곡선보의 면외 진동해석)

  • Kang, Ki-Jun;Kim, Jang-Woo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.4
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    • pp.417-425
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    • 2007
  • The differential quadrature method(DQM) is applied to computation of eigenvalues of the equations of motion governing the free out-of-plane vibration for circular curved beams including the effects of rotatory inertia and transverse shearing deformation. Fundamental frequencies are calculated for the members with clamped-clamped end conditions and various opening angles. The results are compared with exact solutions or numerical solutions by other methods for cases in which they are available. The DQM provides good accuracy even when only a limited number of grid points is used.

Vibration Analysis of Euler-Bernoulli Beam with Open Cracks on Elastic foundations Using Differential Transformation Method and Generalized Differential Quadrature Method (미분변환법과 일반화 미분구적법을 이용한 탄성 지반상의 열림 균열을 가진 Euler-Bernoulli 보의 진동 해석)

  • Hwang Ki-Sup;Yun Jong-Hak;Shin Young-Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.3 s.246
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    • pp.279-286
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    • 2006
  • The main purpose of this paper is to apply differential transformation method(DTM) and generalized differential quadrature method(GDQM) to vibration analysis of Euler-Bernoulli beam with open cracks on elastic foundation. In this paper the concepts of DTM and GDQM were briefly introduced. The governing equation of motion of the beam with open cracks on elastic foundation is derived. The cracks are modeled by massless substitute spring. The effects of the crack location, size and the foundation constants, on the natural frequencies of the beam, are investigated. Numerical calculations are carried out and compared with previous published results.

Free Vibration Analysis of Circular Arches Considering Effects of Midsurface Extension and Rotatory Inertia Using the Method of Differential Quadrature (미분구적법을 이용 중면신장 및 회전관성의 영향을 고려한 원형아치의 고유진동해석)

  • Kang, Ki-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.9-17
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    • 2021
  • Curved beams are increasingly used in buildings, vehicles, ships, and aircraft, which has resulted in considerable effort being directed toward developing an accurate method for analyzing the dynamic behavior of such structures. The stability behavior of elastic circular arches has been the subject of a large number of investigations. One of the efficient procedures for the solution of ordinary differential equations or partial differential equations is the differential quadrature method DQM. This method has been applied to a large number of cases to overcome the difficulties of the complex computer algorithms, as well as excessive use of storage due to conditions of non-linear geometries, loadings, or material properties. This study uses DQM to analyze the in-plane vibration of the circular arches considering the effects of midsurface extension and rotatory inertia. Fundamental frequency parameters are calculated for the member with various parameter ratios, boundary conditions, and opening angles. The solutions from DQM are compared with exact solutions or other numerical solutions for cases in which they are available and given to analyze the effects of midsurface extension and rotatory inertia on the frequency parameters of the circular arches.

In-Plane Buckling Analysis of Asymmetric Curved Beam Using DQM (미분구적법(DQM)을 이용한 비대칭 곡선보의 내평면 좌굴해석)

  • Kang, Ki-Jun;Park, Cha-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.4706-4712
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    • 2013
  • One of the efficient procedures for the solution of partial differential equations is the method of differential quadrature. This method has been applied to a large number of cases to circumvent the difficulties of programming complex algorithms for the computer, as well as excessive use of storage due to conditions of complex geometry and loading. Under in-plane uniform distributed load, the buckling of asymmetric curved beam with varying cross section is analyzed by using differential quadrature method (DQM). Critical load due to diverse cross section variation and opening angle is calculated. Analysis result of DQM is compared with the result of exact analytic solution. As DQM is used with small grid points, exact analysis result is shown. New result according to diverse cross section variation is also suggested.

Extensional Vibration Analysis of Curved Beams Including Rotatory Inertia and Shear Deformation Using DQM (미분구적법(DQM)을 이용 회전관성 및 전단변형을 포함한 곡선 보의 신장 진동해석)

  • Kang, Ki-Jun;Park, Cha-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.284-293
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    • 2016
  • One of the most efficient procedures for the solution of partial differential equations is the method of differential quadrature. The differential quadrature method (DQM) has been applied to a large number of cases to overcome the difficulties of complex algorithms of computer programming, as well as the excessive use of storage due to the conditions of complex geometry and loading. The in-plane vibrations of curved beams with extensibility of the arch axis, including the effects of rotatory inertial and shear deformation, are analyzed by the DQM. The fundamental frequencies are calculated for members with various slenderness ratios, shearing flexibilities, boundary conditions, and opening angles. The results are compared with the numerical results obtained by other methods for cases in which they are available. The DQM gives good mathematical precision even when only a limited number of grid points is used, and new results according to diverse variations are also suggested.