• Title/Summary/Keyword: Dynamic interaction

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The Effect of Fluid-Structure Interaction on the Dynamic Response of Reactor Internals (유체-구조물 상호작용이 원자로내부구조물의 동적응답에 미치는 영향)

  • 정명조;박찬국;황원걸
    • Computational Structural Engineering
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    • v.6 no.4
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    • pp.73-82
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    • 1993
  • Investigated in this paper is the effect of fluid-structure interaction between reactor internal components due to their immersion in a confining fluid on the dynamic responses. A non-linear mathematical model is developed for the dynamic analysis of the reactor internals, which includes lumped masses, stiffnesses and hydrodynamic couplings. The hydrodynamic mass matrix which characterizes the fluid-structure interaction is calculated. Also, the equations of motion containing hydrodynamic mass matrix are presented. The responses of the reactor internals due to seismic and pipe break excitations are obtained for the case of with- and without-hydrodynamic couplings and the different response characteristics are investigated.

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Dynamic Analysis of Base-Isolated Rectangular Liquid Storage Structures (기초격리된 직사각형 유체 저장 구조물의 동적 해석)

  • Park, Jang-Ho
    • Journal of the Korean Society of Safety
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    • v.19 no.4 s.68
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    • pp.109-116
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    • 2004
  • The dynamic behavior of the rectangular liquid storage structure is known to be greatly influenced by fluid-structure interaction. By mounting the liquid storage structure on the properly designed base isolators, dynamic response of the superstructure can be reduced. However, base isolators inevitably incur large displacement of the structure to the ground ·ind may give adverse effects on the sloshing height. This paper presents the analysis method for fluid-structure-isolator interaction in base-isolated rectangular liquid storage structures. In the method, the irrotational motion of invicid and incompressible ideal fluid is expressed by analytic solutions and the superstructure and isolators are properly modeled by finite element and bilinear model. Free surface sloshing motion, hydrodynamic pressure acting on the wall and structural response are obtained by the presented method.

Dynamic Stability Evaluation of Special Bridge for High Speed Railroad under Vertical Ground Motion (연직 지진하중을 받는 고속철도 특수교량의 주행안정성 평가)

  • Kim, Dong-Seok;Kim, Sung-Il
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1464-1469
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    • 2010
  • In this paper, the dynamic stability evaluation of special bridge for high speed railway under ground excitation is performed. The mass, damping, stiffness matrices of bridge are derived from the modal frequencies and mode shape vectors which can be obtained by commercial program. And the high speed train is modeled as multi-single d.o.f models for the sake of vehicle-bridge interaction analysis. In the vehicle-bridge interaction analysis, the vertical directional interaction is only considered. As a numerical example, the 3 span Extradosed bridge which is expected to be installed in Ho-Nam high speed railroad is considered. The analysis results show that the example bridge satisfies the criteria of dynamic stability.

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Ship Collision Analysis of Structure (구조물의 선박충돌 해석)

  • Lee Seong-Lo;Bae Yong-Gwi
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.347-350
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    • 2005
  • A ship collision analysis by finite element method is performed considering the effects of mass and speed of ship and material and shape of structures to analyze the dynamic characteristics by ship collision. From this analysis, collision load-time history and inelastic deformation of ship and structures are obtained. Dynamic characteristics are different from each other according to interaction. between ship and structures. It seems that there are lots of factor to have effects on the ship-structures interaction. But because little information is available on the behavior of the inelastic deformation of materials and structures during the type of dynamic impacts associated with vessel impact, assumptions based on experience and sound engineering practice should be substituted. Therefore more researches on the interaction between ship and structures are required.

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A Study on the Dynamic Interaction for a Pantograph and Rigid contact wire System (도시철도 판토그래프와 강체전차선의 동적 상호작용에 관한 연구)

  • Kwon Kwon-Ki;Cho Yong-Hyun;Kim Ki-Hwan;Won Si-Tae
    • Proceedings of the KSR Conference
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    • 2003.10c
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    • pp.15-21
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    • 2003
  • Generally, subway runs under the ground, so it uses rigid contact wire. Pantograph and contact wire, they have effect on the contact force each other. This paper is on the dynamic interaction of a pantograph and rigid contact wire system. For this we developed simulation program of current collecting capability for dynamic interaction for pantograph and rigid contact wire. As a result, we got contact force and displacement between pantograph and rigid contact wire. This paper shows the possibility of better pantograph's suspension design and better maintaining of current collecting capability than present when suspention of pantograph is developed by theoretic result.

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Three Dimesional Analysis of Liquid Storage Tanks Using FE-BE Coupling Method in Frequency Domin (유한요소-경계요소 조합에 의한 3차원 유체저장 구조물의 주파수 응답해석)

  • 김문겸
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.04a
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    • pp.275-283
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    • 1999
  • To predict the dynamic behavior of the cylindrical liquid storage tank subjected to seismic ground motion three dimesional analysis with liquid-structure interaction must be performed, In this study a three dimensional dynamic analysis method over the frequency domain using FE-BE coupling technique which combines the efficiency of the boundary elements for liquid with the versatility of the finite shell elements for tank. The liquid region is modeled using boundary elements which can counter the sloshing effect at free surface and the structure region the tank itself is modeled using the degenerated finite shell elements. At the beginning of the procedure the equivalent mass matrix of the liquid is generated by boundary elements procedure. Then this equivalent mass matrix is combined with the mass matrix of the structure to produce the global mass matrix in the equation of the motion of fluid-structure interaction problem In order to demonstrate the accuracy and validity of the developed method the numerical results re compared with the previous studies. Finally the effects of the fluid-structure interaction on the natural frequency and dynamic response of the system are analyzed.

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Dynamic Analysis of Rectangular Liquid Storage Containers Considering Fluid-Structure Interaction effects (유체-구조물 상호작용 효과를 고려한 직사각형 단면의 수조구조물의 동적 해석)

  • 박장호;권기준
    • Journal of the Korean Society of Safety
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    • v.15 no.3
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    • pp.96-101
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    • 2000
  • The effects of internal fluid motion have to be considered in the analysis of liquid storage containers. Therefore this thesis developed a three-dimensional boundary element-finite element method for the analysis of rectangular liquid storage containers. The irrotational motion of inviscid and incompressible ideal fluid is modeled by using boundary elements and the motion of structure by finite elements. Coupling is performed by using compatibility and equilibrium conditions along the interface. Dynamic response characteristics of rectangular liquid storage containers such as sloshing motion, hydrodynamic pressure, displacement by fluid-structure interaction are investigated.

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Stochastic analysis of fluid-structure interaction systems by Lagrangian approach

  • Bayraktar, Alemdar;Hancer, Ebru
    • Structural Engineering and Mechanics
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    • v.20 no.4
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    • pp.389-403
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    • 2005
  • In the present paper it is aimed to perform the stochastic dynamic analysis of fluid and fluidstructure systems by using the Lagrangian approach. For that reason, variable-number-nodes twodimensional isoparametric fluid finite elements are programmed in Fortran language by the authors and incorporated into a general-purpose computer program for stochastic dynamic analysis of structure systems, STOCAL. Formulation of the fluid elements includes the effects of compressible wave propagation and surface sloshing motion. For numerical example a rigid fluid tank and a dam-reservoir interaction system are selected and modeled by finite element method. Results obtained from the modal analysis are compared with the results of the analytical and numerical solutions. The Pacoima Dam record S16E component recorded during the San Fernando Earthquake in 1971 is used as a ground motion. The mean of maximum values of displacements and hydrodynamic pressures are compared with the deterministic analysis results.

Theoretical formulation for vehicle-bridge interaction analysis based on perturbation method

  • Tan, Yongchao;Cao, Liang;Li, Jiang
    • Structural Engineering and Mechanics
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    • v.82 no.2
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    • pp.191-204
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    • 2022
  • A three-mass vehicle model including one rigid mass and two unsprung masses is adopted to predict the vehicle-bridge interaction (VBI) and to establish the nonlinear coupled governing equations. To overcome the numerical instability and large computation problems concerning the vehicle-bridge system, the perturbation method is used to convert the nonlinear coupled governing equations into a set of linear uncoupled equations. Formulas for bridge's natural frequencies considering both the VBI and the dynamic responses of bridge and vehicle are proposed. Compared with the numerical results obtained by the Newmark-β method, the theoretical solutions for natural frequencies and dynamic responses are validated. The effects of the important factors of unsprung mass, vehicle damping, surface irregularity on the natural frequencies and dynamic responses of bridge and vehicle are discussed, based on the theoretical solutions.

Seismic response of adjacent buildings interconnected by viscous dampers considering soil-structure interaction

  • Yavuz S. Hatipoglu;Oguz A. Duzgun
    • Earthquakes and Structures
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    • v.24 no.3
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    • pp.165-181
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    • 2023
  • The effectiveness of fluid viscous dampers (FVDs) on dynamic response mitigation of coupled two adjacent structures was investigated, considering soil-structure interaction (SSI) effects under earthquake excitation. A numerical procedure was employed to evaluate system response. The finite elements were used for the numerical treatment of the adjacent buildings and soil region. Viscous boundary conditions were used as special non-reflecting boundaries on the edges of finite soil region. According to the results, the FVDs were found to be very effective for dynamic response mitigation of the adjacent buildings, even if considering the soil medium. The results showed that the most affecting parameter on the system response was found to be soil type. It was also concluded that when adjacent structures coupled by FVDs, the maximum values of the roof displacements, the base shear forces, and the base bending moments could decrease up to around 50%. Changing in lateral stiffness of the one building has minor effects on the effectiveness of viscous dampers.