• Title/Summary/Keyword: Continuous Supports

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Vibration Analysis of Partially Fluid-filled Continuous Cylindrical Shells with Intermediate Supports (유체가 부분적으로 채워진 내부지지 연속 원통셸의 진동해석)

  • 김영완
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.3
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    • pp.244-252
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    • 2004
  • The theoretical method is developed to investigate the vibration characteristics for the partially fluid-filled continuous cylindrical shells with the intermediate supports. The intermediate supports are simulated by two types of artificial springs : the translational spring for the translation for each direction and the rotational spring for a rotation. The springs are continuously distributed along the circumferential direction. By allowing the spring stiffness to become very high compared to the stiffness of the structure, the rigid intermediate supports are approximated. In the theoretical procedure, the Love's thin shell theory is adopted to formulate the theoretical model. The frequency equation of the continuous cylindrical shell is derived by the Rayleigh-Ritz approach based on the energy method. Comparison and convergence studies are carried out to verify and establish the appropriate number of series term and the artificial spring stiffness to produce results with an acceptable order of accuracy. The effect of intermediate supports, their positions and fluid level on the natural frequencies and mode shapes are studied.

Simple Method of Vibration Analysis of Three Span Continuous Composite Slab Bridges with Elastic Intermediate Supports (탄성지지된 3경간 연속 복합슬래브교량의 간단한 진동해석)

  • Han, Bong Koo;Kim, Duk Hyun
    • Journal of Korean Society of Steel Construction
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    • v.17 no.3 s.76
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    • pp.317-324
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    • 2005
  • The specially orthotropic plate theory is used to analyse three-span continuous composite slab bridges with elastic intermediate supports. A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross sections and with arbitrary boundary conditions, was developed and the result of application of this method to the three-span continuous composite slab bridges with elastic intermediate supports is presented. This type of bridge represents either concrete or sandwich type three-span bridge on polymeric supports for passive control or on actuators for active control. Any method may be used to obtain the deflection influence surfaces needed for this vibration analysis. The finite difference method is used for this purpose in this paper. The influence of flexural stiffnesses and the modulus of the foundation are studied.

A Free Vibration Analysis of the Continuous Circular Cylindrical Shell with the Multiple Simple Supports Using the Receptance Method (동적응답법을 이용한 다점 단순지지된 연속원통셸의 자유진동 해석)

  • 이영신;한창환
    • Journal of KSNVE
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    • v.10 no.6
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    • pp.998-1008
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    • 2000
  • The continuous circular cylindrical shells are widely used for the high performance structures of aircraft, spacecraft, missile, nuclear fuel rod shell etc.. In this paper, a method for the free vibration analysis of the continuous circular cylindrical shells with the multiple simple supports is developed by using the receptance method. With this method, the vibrational characteristics of the continuous system is analyzed by considering as a combined structure. The system receptance is also derided by the application of the equilibrium of forces and the continuity of displacements at the support points. The natural frequencies and mode shapes are calculated numerically and they are compared with the FEM results to improve the reliability of analytical solution. Numerical results on the 4-equal-span continuous circular cylindrical shell are presented in this paper.

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Vibration Analysis of the Continuous Circular Cylindrical Shell with the Clamped-clamped Supports at Two End Edges (양단이 고정지지된 연속원통셸의 진동특성 해석)

  • 한창환;이영신
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.2
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    • pp.97-107
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    • 2002
  • The continuous circular cylindrical shells are widely used for the high performance structures of aircraft, spacecraft, missile, nuclear fuel rod shell and so on. In this paper, a method for the vibrational analysis of the continuous circular cylindrical shells with the clamped-clamped supports at two end edges is developed by using the modal expansion method. Forces and/or moments acting on the shell surface are expressed in terms of the Dirac Delta Function. Frequency equation of the continuous shell is also derided by the application of the equilibrium of forces and the continuity of displacements at the boundary. Natural frequencies of the continuous shell are calculated numerically with mathematica 3.0 and they are compared with FEM results from the ANSYS 5.3 to improve the reliability of analytic solutions. Mode shares obtained by the FEM are Presented in this paper.

Vibration Analysis of Three Span Continuous Reinforced Concrete Bridge with Elastic Intermediate Supports II

  • Kim, Duk-hyun;Han, Bong-Koo;Lee, Jung-Ho;Park, Ji-Hyun
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.11a
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    • pp.220-223
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    • 2000
  • A method of calculating the natural frequency corresponding to the modes of vibration of beams and tower structures, with irregular cross sections and with arbitrary boundary conditions was developed and reported by Kim, D. H. in 1974. In this paper, the result of application of this method to the three span continuous reinforced concrete bridge with elastic intermediate supports is presented. Such bridge represents either concrete or sandwich type three span bridge on polymeric supports for passive control or on actuators for active control The concrete slab is considered as a special orthotropic plate. The influence of the modulus of the foundation and $D_{22}$, $D_{12}$, $D_{66}$ stiffnesses on the natural frequency is thoroughly studied.

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Study on the Prestressing Effect of 3 Span Continuous Preflex Composite Beam of Bridges by Re-Up Down of Supports (지점 재 상승·하강에 의한 3경간 연속 프리플렉스 합성형의 프리스트레싱 효과에 관한 연구)

  • Koo, Min Se;Park, Young Je;Kim, Phil Sik
    • Journal of Korean Society of Steel Construction
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    • v.13 no.4
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    • pp.433-441
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    • 2001
  • Thus study presents the basic concepts of 3 span continuous preflex composite beam of bridges by re-up down of supports and analysis relationship of between variables and stress of critical section. Also, it shows the pre-compression effects of re-up down of supports method by presenting the difference of between old section and new section got from new method. This study's new method makes more economic sections to be possible and when the sections designed with the existing method are used in the new method. efficient stress state is accomplished.

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An efficient and novel strategy for control of cracking, creep and shrinkage effects in steel-concrete composite beams

  • Varshney, L.K.;Patel, K.A.;Chaudhary, Sandeep;Nagpal, A.K.
    • Structural Engineering and Mechanics
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    • v.70 no.6
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    • pp.751-763
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    • 2019
  • Steel-concrete composition is widely used in the construction due to efficient utilization of materials. The service load behavior of composite structures is significantly affected by cracking, creep and shrinkage effects in concrete. In order to control these effects in concrete slab, an efficient and novel strategy has been proposed by use of fiber reinforced concrete near interior supports of a continuous beam. Numerical study is carried out for the control of cracking, creep and shrinkage effects in composite beams subjected to service load. A five span continuous composite beam has been analyzed for different lengths of fiber reinforced concrete near the interior supports. For this purpose, the hybrid analytical-numerical procedure, developed by the authors, for service load analysis of composite structures has been further improved and generalized to make it applicable for composite beams having spans with different material properties along the length. It is shown that by providing fiber reinforced concrete even in small length near the supports; there can be a significant reduction in cracking as well as in deflections. It is also observed that the benefits achieved by providing fiber reinforced concrete over entire span are not significantly more as compared to the use of fiber reinforced concrete in certain length of beam near the interior supports in continuous composite beams.

The Role of Organizational Members in Implementing and Achieving Successful Cloud Computing: The Moderating Effects of Leadership and Continuous Supports (성공적인 클라우드 컴퓨팅 구현과 성과를 높이기 위한 조직 구성원의 역할: 리더십과 지속적 지원의 조절효과)

  • Kim, Sanghyun;Park, Hyunsun
    • The Journal of Information Systems
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    • v.29 no.2
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    • pp.197-220
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    • 2020
  • Purpose Cloud computing that provides a new paradigm for a firm's use of information technology is getting a lot of attentions by practitioners. However, the empirical investigation on members of organizations using cloud computing are insufficient. Therefore, this study aims to examine the capabilities and perceptions of organizational members that should be considered important for successful cloud computing implementation. Design/methodology/approach This study proposed factors related to the capabilities and perceptions of members of the organization, and examined the relationship between these factors and successful cloud computing implementation and performance. In addition, this study tested the moderating effect of leadership and continuous supports through empirical analysis. The proposed hypotheses were verified through structural equation modeling using SmartPLS3.0 with the collected data. Findings The results showed that four factors except 'member behavior control' had a positive effect on successful cloud computing implementation, which had a positive effect on performance. In addition, leadership and organizational continuous support have been shown to strengthen the relationship among factors.

Analysis of Rectangular Plates under Distributed Loads of Various Intensity with Interior Supports at Arbitrary Positions (분포하중(分布荷重)을 받는 구형판(矩形板)의 탄성해석(彈性解析))

  • Suk-Yoon,Chang
    • Bulletin of the Society of Naval Architects of Korea
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    • v.13 no.1
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    • pp.17-23
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    • 1976
  • Some methods of analysis of rectangular plates under distributed load of various intensity with interior supports are presented herein. Analysis of many structures such as bottom, side shell, and deck plate of ship hull and flat slab, with or without internal supports, Floor systems of bridges, included crthotropic bridges is a problem of plate with elastic supports or continuous edges. When the four edges of rectangular plate is simply supported, the double Fourier series solution developed by Navier can represent an exact result of this problem. If two opposite edges are simply supported, Levy's method is available to give an "exact" solution. When the loading condition and supporting condition of a plate does not fall into these cases, no simple analytic method seems to be feasible. Analysis of a simply supported rectangular plate under irregularly distributed loads of various intensity with internal supports is carried out by applying Navier solution well as the "Principle of Superposition." Finite difference technique is used to solve plates under irregularly distributed loads of various intensity with internal supports and with various boundary conditions. When finite difference technique is applied to the Lagrange's plate bending equation, any of fourth order derivative term in this equation produces at least five pivotal points leading to some troubles when the resulting linear algebraic equations are to be solved. This problem was solved by reducing the order of the derivatives to two: the fourth order partial differential equation with one dependent variable, namely deflection, is changed to an equivalent pair of second order partial differential equations with two dependent variables. Finite difference technique is then applied to transform these equations to a set of simultaneous linear algebraic equations. Principle of Superposition is then applied to handle the problems caused by concentrated loads and interior supports. This method can be used for the cases of plates under irregularly distributed loads of various intensity with arbitrary conditions such as elastic supports, or continuous edges with or without interior supports, and this method can also be solve the influence values of deflection, moment and etc. at arbitrary position of plates under the live load.

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