Model Updating of Fluid-Structure Interaction Effects on Piping System

Author(s):  
Srijan Rajbamshi ◽  
Qintao Guo ◽  
Ming Zhan
1999 ◽  
Author(s):  
Zongxia Jiao ◽  
Qing Hua ◽  
Kai Yu

Abstract In the analysis of liquid-filled piping systems there are Poisson-coupled axial stress waves in the pipe and liquid column, which are caused by the dilation of the pipe. In some conditions the influence of viscous friction that is usually frequency-dependent should not be omitted, which in fact is another kind of coupled form. It directly influences the amplitude of vibration of piping systems to some degree. The larger the viscosity of the liquid is, the greater the influence will be. Budny (1991) included the viscous friction influence in time domain analysis of fluid-structure interaction, but did not give frequency domain analysis. Lesmez (1990) gave the model analysis liquid-filled piping systems without considering friction. If the friction is not included in frequency domain analysis, the vibration amplitude will be greater than that when friction is included, especially at harmony points, cause large errors in the simulation of fluid pipe network analysis, although it may have little influence on the frequency of harmony points. The present paper will give detail solutions to the transfer matrix that represents the motion of single pipe section, which is the basis of complex fluid-structure interaction analysis. Combined with point matrices that describe specified boundary conditions, overall transfer matrix for a piping system can be assembled. Corresponding state vectors can then be evaluated to predict the piping and liquid motion. At last, a twice-coordinate transformation method is adopted in joint coupling. Consequently, the vibration analysis of spatial liquid-filled piping systems can be carried out. It is proved to be succinct, valid and versatile. This method can be extended to the simulation of the curved spatial pipeline systems.


Author(s):  
A. R. M. Gharabaghi ◽  
A. Arablouei ◽  
A. Ghalandarzadeh ◽  
K. Abedi

The dynamic response of gravity type quay wall during earthquake including soil-sea-structure interaction is calculated using ADINA finite element techniques. The main objective of this study is to investigate the effects of fluid-structure interaction on the residual displacement of wall after a real earthquake. A direct symmetric coupled formulation based on the fluid velocity potential is used to calculate the nonlinear hydrodynamic pressure of sea water acting on the wall. The doubly asymptotic approximation (DAA) is used to account for the effects of outer fluid on the inner region. The non-associated Mohr-Coulomb material behavior is applied to model the failure of soil. The full nonlinear effective stress analysis is performed in this study and the soil-pore fluid interaction effects are modeled using porous media formulation. Viscous boundary condition is implemented to model the artificial boundary in direct method analysis of soil-structure interaction system and sliding contact condition was modeled in the interface of wall and surrounding soil. A typical configuration of gravity quay wall is used for analysis and three real earthquakes excitation are applied as base acceleration. The results show that influence of fluid-structure interaction effects on the permanent displacement of a gravity quay wall constructed on relatively non-liquefiable site is not considerable.


2006 ◽  
Vol 129 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Jean-François Sigrist ◽  
Daniel Broc ◽  
Christian Lainé

The present paper deals with the modal analysis of a nuclear reactor with fluid-structure interaction effects. The proposed study aims at describing various fluid-structure interaction effects using several numerical approaches. The modeling lies on a classical finite element discretization of the coupled fluid-structure equation, enabling the description of added mass and added stiffness effects. A specific procedure is developed in order to model the presence of internal structures within the nuclear reactor, based on periodical homogenization techniques. The numerical model of the nuclear pressure vessel is developed in a finite element code in which the homogenization method is implemented. The proposed methodology enables a convenient analysis from the engineering point of view and gives an example of the fluid-structure interaction effects, which are expected on an industrial structure. The modal analysis of the nuclear pressure vessel is then performed and highlights of the relative importance of FSI effects for the industrial case are evaluated: the analysis shows that added mass effects and confinement effects are of paramount importance in comparison to added stiffness effects.


1986 ◽  
Vol 108 (3) ◽  
pp. 249-255 ◽  
Author(s):  
T. Belytschko ◽  
M. Karabin ◽  
J. I. Lin

In the waterhammer analysis of piping systems, incompressible (or added mass) representations are generally used in computing the response of the piping. It is shown that this procedure is not necessarily conservative, particularly for thin-walled, flexible piping systems, and that fully coupled fluid-structure solutions can predict higher loads and stresses. A modal recovery procedure which easily permits the representation on the acoustic effects of the fluid to be included in a structural model is also presented. Results are given for both simple models and a piping system from an LMFBR design.


2009 ◽  
Vol 131 (6) ◽  
Author(s):  
P. Tang ◽  
J. Yang ◽  
J. Y. Zheng ◽  
C. K. Lam ◽  
I. Wong ◽  
...  

Erosion-corrosion failures frequently found in piping systems can lead to the leakage of pipes, or even damage of the whole system. Erosion-corrosion is a form of material degradation that involves electrochemical corrosion and mechanical wear processes encountered on the surface of metal pipes. Fluid-structure interactions have a profound influence on such erosion-corrosion phenomena. This paper is focused on the multiphase flow-induced erosion-corrosion phenomena in pipes, with multiscale analysis, to study the interactions between the flow and the protective film inside the piping system. The shear stress and the pressure of the flow in a pipe with a step were first obtained using a multiphase flow dynamic analysis. The erosion-corrosion rules of the pipes under the multiphase flow were then summarized. Using the microscale flow simulation method, the fluid-structure interaction between the flow and the protective film at the critical position was modeled. The deformation of the protective films was shown to vary with the flow velocity and the corresponding flow regime. According to the simulation results of the fluid-structure interaction, the location, rate, and extent of the erosion-corrosion on pipe surfaces can be predicted. The prediction was also proven by actual instances. Moreover, the method can be used in optimizing the design of the inner sleeves of pipes.


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