Modal Analysis for Beam Bundle in Fluid

2002 ◽  
Vol 124 (2) ◽  
pp. 223-228
Author(s):  
R. J. Zhang ◽  
W. Q. Wang ◽  
S. H. Hou ◽  
C. K. Chan
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Modal Analysis ◽  
Velocity Potential ◽  
Fluid Velocity ◽  
Fluid Pressure ◽  
Response Analysis ◽  
Gyroscopic System ◽  
Similar Relation ◽  
Homogenized Model

In the present paper, a 3-D homogenized model for beam bundle in fluid is developed and formulated in terms of fluid velocity potential and displacement of beams as fundamental unknowns. It can be seen that the homogenized model is associated with a set of finite element equations in the form of a conservative gyroscopic system. Based on these equations, an algorithm for the modal analysis and the dynamic response analysis of the beam bundle is also given. It is found that both the displacement and the fluid pressure response of the bundle have a similar relation with time, but different amplitudes.

Parametric Design and Modal Analysis on Four-Order Elliptical Gear

2013 ◽  
Vol 423-426 ◽  
pp. 1516-1519
Author(s):  
Zhi Dong Huang ◽  
An Min Hui ◽  
Guang Yang ◽  
Rui Yang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Response ◽  
Modal Analysis ◽  
Dynamic Model ◽  
Natural Frequencies ◽  
Parametric Design ◽  
Three Dimensional ◽  
Response Analysis ◽  
Dynamic Design

The characteristics of four-order elliptical gear is analyzed. The parameters of four-order elliptical gear are chosen and calculated. The three-dimensional solid modeling of four-order elliptical gear is achieved. The dynamic model of four-order elliptical gear is established by finite element method and modal analysis of four-order elliptical gear is investigated. The natural frequencies and major modes of the first six orders are clarified. The method and the result facilitate the dynamic design and dynamic response analysis of high-order elliptical gear.

Dynamic response analysis of aero hydraulic pipeline system under pump fluid pressure fluctuation

2018 ◽  
Vol 233 (5) ◽  
pp. 1585-1595 ◽  
Author(s):  
Pei-xin Gao ◽  
Jing-yu Zhai ◽  
Qing-kai Han
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Response ◽  
Pressure Fluctuation ◽  
Method Of Characteristics ◽  
Fluid Pressure ◽  
Numerical Code ◽  
Response Analysis ◽  
Pipeline System ◽  
Element Method

The pressure fluctuation excited by the hydraulic pump can cause serious vibration in aero hydraulic pipeline system, which poses a serious threat to the safety of the aircraft. Therefore, an effective method for predicting the fluid pressure fluctuation and dynamic response of pipeline is strongly recommended. In this paper, a comprehensive model for predicting the dynamic response of pipeline, which includes the Poisson coupling, friction coupling, the vibration damping, Coriolis, and centrifugal forces is proposed. A numerical code is presented to solve the hydraulic pipeline equations. In this code, the hydraulic equations are solved by the method of characteristics and the dynamic equations of pipeline are solved by the finite element method combined with the Newmark algorithm. The numerical code is validated through the comparison of the dynamic response for a typical hydraulic pipeline with experiment. The obtained results indicate that the current combining method of characteristics and finite element method approach can predict the dynamic response of hydraulic pipeline with sufficient accuracy, which can serve as an efficient tool in the design and maintenance of aero hydraulic pipeline.

Dynamic Response Analysis for Two Typical Structures of Saturated Asphalt Pavements with 3D Finite Element Method

2011 ◽  
Vol 255-260 ◽  
pp. 3391-3396
Author(s):  
Rui Bo Ren ◽  
Li Tao Geng ◽  
Wen Yang Qi
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Asphalt Pavement ◽  
Fluid Pressure ◽  
Asphalt Mixture ◽  
Temporal Distribution ◽  
Element Model ◽  
Response Analysis ◽  
Flexible Base ◽  
Base Course

The combined effect of moisture and dynamic loading on asphalt mixtures has been recognized as one of the main causes of premature deterioration of flexible pavements. Based on porous medium theory, the asphalt mixture is regard as saturated porous material, and a three-dimensional finite element model is established to investigate dynamic response of two typical asphalt pavement structures, which are the semi-rigid asphalt pavement and the semi-rigid asphalt pavement with flexible base course. Then the spatial and temporal distribution of stress, strain and pore fluid pressure of the two structures are calculated, respectively. Analysis results show the superiority of semi-rigid asphalt pavement structure with flexible base course to the semi-rigid asphalt pavement in aspect of moisture resistance capability.

Fluid Pressures on Unanchored Rigid Flat-Bottom Cylindrical Tanks Under Action of Uplifting Acceleration

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Tomoyo Taniguchi ◽  
Yoshinori Ando
Keyword(s):  
Velocity Potential ◽  
Fluid Velocity ◽  
Fluid Pressure ◽  
Angular Acceleration ◽  
Bottom Plate ◽  
Center Line ◽  
Cylindrical Tank ◽  
Cylindrical Coordinates ◽  
Flat Bottom ◽  
Cylindrical Tanks

To protect flat-bottom cylindrical tanks against severe damage from uplift motion, accurate evaluation of accompanying fluid pressures is indispensable. This paper presents a mathematical solution for evaluating the fluid pressure on a rigid flat-bottom cylindrical tank in the same manner as the procedure outlined and discussed previously by the authors (Taniguchi, T., and Ando, Y., 2010, “Fluid Pressures on Unanchored Rigid Rectangular Tanks Under Action of Uplifting Acceleration,” ASME J. Pressure Vessel Technol., 132(1), p. 011801). With perfect fluid and velocity potential assumed, the Laplace equation in cylindrical coordinates gives a continuity equation, while fluid velocity imparted by the displacement (and its time derivatives) of the shell and bottom plate of the tank defines boundary conditions. The velocity potential is solved with the Fourier–Bessel expansion, and its derivative, with respect to time, gives the fluid pressure at an arbitrary point inside the tank. In practice, designers have to calculate the fluid pressure on the tank whose perimeter of the bottom plate lifts off the ground like a crescent in plan view. However, the asymmetric boundary condition given by the fluid velocity imparted by the deformation of the crescent-like uplift region at the bottom cannot be expressed properly in cylindrical coordinates. This paper examines applicability of a slice model, which is a rigid rectangular tank with a unit depth vertically sliced out of a rigid flat-bottom cylindrical tank with a certain deviation from (in parallel to) the center line of the tank. A mathematical solution for evaluating the fluid pressure on a rigid flat-bottom cylindrical tank accompanying the angular acceleration acting on the pivoting bottom edge of the tank is given by an explicit function of a dimensional variable of the tank, but with Fourier series. It well converges with a few first terms of the Fourier series and accurately calculates the values of the fluid pressure on the tank. In addition, the slice model approximates well the values of the fluid pressure on the shell of a rigid flat-bottom cylindrical tank for any points deviated from the center line. For the designers’ convenience, diagrams that depict the fluid pressures normalized by the maximum tangential acceleration given by the product of the angular acceleration and diagonals of the tank are also presented. The proposed mathematical and graphical methods are cost effective and aid in the design of the flat-bottom cylindrical tanks that allow the uplifting of the bottom plate.

Dynamics Analysis of Refrigeration Compressor Based on Finite Element and Experimental Modes

2012 ◽  
Vol 499 ◽  
pp. 238-242
Author(s):  
Li Zhang ◽  
Hong Wu ◽  
Yan Jue Gong ◽  
Shuo Zhang
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Modal Analysis ◽  
Natural Frequency ◽  
High Precision ◽  
3D Model ◽  
Finite Element Models ◽  
Dynamics Analysis ◽  
Response Characteristics ◽  
Dynamic Response Characteristics

Based on the 3D model of refrigeration's compressor by Pro/E software, the analyses of theoretical and experimental mode are carried out in this paper. The results show that the finite element models of compressor have high precision dynamic response characteristics and the natural frequency of the compressor, based on experimental modal analysis, can be accurately obtained, which will contribute to further dynamic designs of mechanical structures.

BLOOD FLOW IN CORONARY ARTERY BIFURCATION CALCULATED BY TURBULENT FINITE ELEMENT MODEL

2021 ◽  
Author(s):  
Aleksandar Nikolić ◽  
◽  
Marko Topalović ◽  
Milan Blagojević ◽  
Vladimir Simić
Keyword(s):  
Finite Element ◽  
Blood Flow ◽  
Kinetic Energy ◽  
Finite Element Model ◽  
Fluid Velocity ◽  
Fluid Pressure ◽  
Element Model ◽  
Viscous Sublayer ◽  
Flow Problems ◽  
Analysis Of Results

Simulation of blood flow in this paper is analyzed using two-equation turbulent finite element model that can calculate values in the viscous sublayer. Implicit integration of the equations is used for determining the fluid velocity, fluid pressure, turbulence, kinetic energy, and dissipation of turbulent kinetic energy. These values are calculated in the finite element nodes for each step of incremental- iterative procedure. Developed turbulent finite element model, with the customized generation of finite element meshes, is used for calculating complex blood flow problems. Analysis of results showed that a cardiologist can use proposed tools and methods for investigating the hemodynamic conditions inside bifurcation of arteries.

The Finite Element Analysis of Dynamic Interaction of High-Speed Shinkansen, the Rail, and Bridge

1993 ◽  
Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Nobuyuki Matsumoto
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
High Speed ◽  
Response Analysis ◽  
Element Formulation ◽  
Element Analysis ◽  
Finite Element Program ◽  
The Finite Element Analysis ◽  
Element Program ◽  
The Impact

Abstract A finite element formulation to solve the dynamic behavior of high-speed Shinkansen cars, rail, and bridge is given. A mechanical model to express the interaction between wheel and rail is described, in which the impact of the rail on the flange of wheel is also considered. The bridge is modeled by using various finite elements such as shell, beam, solid, spring, and mass. The equations of motions of bridge and Shinkansen cars are solved under the constitutive and constraint equations to express the interaction between rail and wheel. Numerical method based on a modal transformation to get the dynamic response effectively is discussed. A finite element program for the dynamic response analysis of Shinkansen cars, rail, and bridge at the high-speed running has been developed. Numerical examples are also demonstrated.

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