Application of Transfer Matrix Method to Dynamic Analysis of Pipes With FSI

Author(s):  
Shuaijun Li ◽  
Bryan W. Karney ◽  
Gongmin Liu

Analytical models of three dimensional pipe systems with fluid structure interaction (FSI) are described and discussed, in which the longitudinal vibration, transverse vibration and torsional vibration were included. The transfer matrix method (TMM) is used for the numerical modeling of both fluidic and structural equations and then applied to the problem of predicting the natural frequencies, modal shapes and frequency responses of pipe systems with various boundary conditions. The main advantage of the present approach is that each pipe section of pipe system can be independently analyzed by a unified matrix expression. Thus the modification of any parameter such as pipe shapes and branch numbers does not involve any change to the solution procedures. This makes a parameterized analysis and further mechanism investigation much easier to perform compared to most existing procedures.

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Masayuki Arai ◽  
Shoichi Kuroda ◽  
Kiyohiro Ito

Abstract Pipe systems have been widely used in industrial plants such as power stations. In these systems, the displacement and stress distributions often need to be predicted. Analytical and numerical methods, such as the finite element method (FEM), boundary element method (BEM), and frame structure method (FSM), are typically adopted to predict these distributions. The analytical methods, which can only be applied to problems with simple geometries and boundary conditions, are based on the Timoshenko beam theory. Both FEM and BEM can be applied to more complex problems, although this usually requires a stiffness matrix with a large number of degrees-of-freedom. In FSM, although the structure is modeled by a beam element, the stiffness matrix still becomes large; furthermore, the matrix size needed in FEM and BEM is also large. In this study, the transfer matrix method, which is simply referred to as TMM, is studied to effectively solve complex problems, such as a pipe structure under a small size stiffness matrix. The fundamental formula is extended to a static elastic-plastic problem. The efficiency and simplicity of this method in solving a space-curved pipe system that involves an elbow are demonstrated. The results are compared with those obtained by FEM to verify the performance of the method.


1993 ◽  
Vol 115 (4) ◽  
pp. 490-497 ◽  
Author(s):  
An-Chen Lee ◽  
Yuan-Pin Shih ◽  
Yuan Kang

A general transfer matrix method (GTMM) is developed in the present work for analyzing the steady-state responses of rotor-bearing systems with an unbalancing shaft. Specifically, we derived the transfer matrix of shaft segments by considering the state variables of shaft in a continuous system sense to give the most general formulation. The shaft unbalance, axial force, and axial torque are all taken into consideration so that the completeness of transfer matrix method for steady-state analysis of linear rotor-bearing systems is reached. To demonstrate the effectiveness of this approach, a numerical example is presented to estimate the effect of three-dimensional distribution of shaft unbalance on the steady-state responses by GTMM and finite element method (FEM).


Author(s):  
Masayuki Arai ◽  
Shoichi Kuroda ◽  
Kiyohiro Ito

Abstract Pipe systems have been widely used in industrial plants such as power stations. In these systems, it is often required to predict the displacement and stress distribution. Analytical and numerical methods such as the finite element method (FEM), boundary element method (BEM), and frame structure method (FSM) are typically adopted to predict the displacement and stress distribution. The analytical methods are solved based on the Timoshenko beam theory, but the problem that can be solved is limited to simple geometry under simple boundary conditions. Both FEM and BEM can be applied to more complicated problems, although this usually involves a large number of degrees of freedom in a stiffness matrix. The structure is modeled by a beam element in FSM. However, the stiffness matrix still becomes large, as does the matrix size constructed in FEM and BEM. In this study, the transfer matrix method (TMM) is studied to effectively solve complicated problems such as a pipe structure under a small size of the stiffness matrix. The fundamental formula is extended to apply to an elastic-plastic problem. The efficiency and simplicity of this method is demonstrated to solve a space-curved pipe system that involves elbows. The results are compared with those obtained by FEM to verify this method.


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