Green's function and finite element formulations for the dynamics of pipeline conveying fluid

2021 ◽  
pp. 1-18
Author(s):  
Fong Kah Soon ◽  
Tan Phey Hoon ◽  
Mohamed Latheef ◽  
A. Y. Mohd. Yassin
Keyword(s):  
Finite Element ◽  
Green’S Function ◽  
Green's Function ◽  
Finite Element Formulations ◽  
Conveying Fluid

scholarly journals Finite element based Green’s function integral equation for modelling light scattering

2019 ◽  
Vol 27 (11) ◽  
pp. 16047 ◽  
Author(s):  
Wen Li ◽  
Dong Tan ◽  
Jing Xu ◽  
Shubo Wang ◽  
Yuntian Chen
Keyword(s):  
Integral Equation ◽  
Finite Element ◽  
Light Scattering ◽  
Green’S Function ◽  
Green's Function

Formulation of Three-Dimensional Green’s Function and its Application to Fatigue Life Evaluation of Pressurizer

2006 ◽  
Vol 324-325 ◽  
pp. 387-390
Author(s):  
Yoon Suk Chang ◽  
Shin Beom Choi ◽  
Jae Boong Choi ◽  
Young Jin Kim ◽  
Myung Jo Jhung ◽  
...  
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Green’S Function ◽  
Green's Function ◽  
Three Dimensional ◽  
Stress Transfer ◽  
Life Assessment ◽  
Element Analysis ◽  
Fatigue Evaluation ◽  
Effective Assessment

Major nuclear components have been designed by conservative codes to prevent unanticipated fatigue failure. However, more realistic and effective assessment is necessary in proof of continued operation beyond the design life. In the present paper, three-dimensional stress and fatigue evaluation is carried out for pressurizer employing complex full geometry itself instead of conventional discrete subcomponents. For this purpose, temperature and mechanical stress transfer Green’s functions are derived from finite element analyses and applied to critical locations of pressurizer. In accordance with comparison of resulting stresses obtained from the Green’s function and detailed finite element analysis, suitability of the specific Green’s function is investigated. Finally, prototype of fatigue life assessment results is provided along with relevant ongoing activities.

Dynamic Behavior of String Subjected to Travelling Mass

2019 ◽  
Author(s):  
Shakti P. Jena ◽  
S. Naresh Kumar ◽  
Hemanth Cheedella
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Green’S Function ◽  
Dynamic Behavior ◽  
Green's Function ◽  
Transverse Vibration ◽  
Element Model ◽  
Numerical Approach ◽  
Complete Analysis ◽  
Numerical Example

Abstract The present study is based on the transverse vibration analogy of a string subjected to a travelling mass. The string is considered to be fixed at their both ends. The responses of the string due to the dynamic behavior of the travelling mass are determined using a numerical approach i.e. Green’s function. A Finite Element Model (FEM) has been developed to authenticate the numerical approach. For the responses analysis of the string, numerical example has been illustrated to study the behavior of the string due to the travelling mass and to check the convergence of the two proposed analogies (Green’s function and FEM). The complete analysis has been performed at constant travelling speed and different masses. The two approaches converge well and the Green’s function methodology found to be suitable one.

Development of a Three-Dimensional Green’s Function and Its Application to the Fatigue Evaluation of Reactor Pressure Vessel

2006 ◽  
Author(s):  
M. Y. Ahn ◽  
J. C. Kim ◽  
Y. S. Chang ◽  
J. B. Choi ◽  
Y. J. Kim ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Green’S Function ◽  
Green's Function ◽  
Pressure Vessel ◽  
Three Dimensional ◽  
Reactor Pressure Vessel ◽  
Element Analysis ◽  
Reactor Pressure

The design of major nuclear components for the prevention of fatigue failure has been achieved on the basis of ASME codes, which are usually very conservative. However, it is necessary to make it more accurate for the continued operation beyond the design life. In this paper, 3-dimensional stress and fatigue analyses reflecting entire geometry have been carried out. The number of operating transient data obtained from a monitoring system were filtered and analyzed. Then, Green’s function which transfers temperature gradient into the corresponding thermal stress is proposed and applied to critical locations of a reactor pressure vessel. The validity of proposed Green’s function is approved by comparing the result with corresponding 3-D finite element analysis results. Also, the amount of conservatism included in design transients in comparison with real transients is analyzed. The results for 3-D finite element analysis are also compared with corresponding 2-D finite element analysis results, and a considerable amount of difference was observed in terms of fatigue life. Therefore, it is expected that the proposed evaluation scheme adopting real operating data and Green’s function can provide more accurate fatigue life evaluation for a reactor pressure vessel.

Numerical Evaluation of a Band-Limited Green’s Function Using the Finite Element Method for Acoustic Emission Analysis

Volume 1 ◽  
2004 ◽  
Author(s):  
Ramez-Robert Naber ◽  
Hamid Bahai ◽  
Barry E. Jones
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Acoustic Emission ◽  
Green’S Function ◽  
Green's Function ◽  
The Finite Element Method ◽  
Transient Wave ◽  
Emission Analysis ◽  
Band Limited ◽  
Element Method

The ability to model transient wave propagation in solids and determine the Green’s function plays a major role in improving the reliability of quantitative source characterization of acoustic emission. In this work, the finite element method is employed to determine a numerical solution of the Green’s function of an isotropic plate due to a point source applied normally to the surface. The advantage of using the finite element method is that it can be extended to model realistic geometries that cannot be treated analytically. The numerical results presented here are based on a two-dimensional axisymmetric transient finite element analysis. A limited bandwidth approximation of a delta function is used (Hanning function) for modeling the source. Hence the solution is called the band-limited Green’s function. The exact analytical solutions of the Green’s function of an isotropic infinite plate are used to validate the numerical solutions. Further analysis is carried out to investigate the effects of varying the spatial resolution of the finite element model on the accuracy of the solutions. Finally, it is demonstrated how the results of the band-limited Green’s function can be used to accurately convolve the response of an arbitrary source function.

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