Effect of Hydrostatic Pressure and Depth of Fluid on the Vibrating Rectangular Plates Partially in Contact with a Fluid

2011 ◽  
Vol 110-116 ◽  
pp. 927-935
Author(s):  
Korosh Khorshidi

This study is focused on vibration analysis of a rectangular plate in partial coupled with a vertical bounded fluid. The fluid displacement potential satisfying the fluid boundary conditions is derived and the wet dynamic modal functions of the plate are expanded in terms of the finite Fourier series for a compatibility requirement along the contacting surface between the plate and the fluid. The natural frequencies of the plate coupled with sloshing fluid modes are calculated using Rayleigh–Ritz method based on minimizing the Rayleigh quotient. The proposed analytical method is verified by comparing the presented results with the results obtained by three–dimensional finite element analysis. Finally, the influence of hydrostatic pressure and fluid depth on the natural frequencies are examined and discussed in details.

Author(s):  
Kyeong-Hoon Jeong ◽  
Jin-Seok Park ◽  
Won-Jae Lee

This paper presents a theoretical analysis for the hydroelastic vibration of a rectangular tank partially filled with an ideal liquid. The wet dynamic displacement of the tank is approximated by combining the orthogonal polynomials satisfying the simply supported boundary conditions, since the rectangular tank is composed of four rectangular plates. As the facing rectangular plates are geometrically identical, the vibration modes of the facing plates can be divided into two categories: symmetric modes and asymmetric modes with respect to the vertical centerlines of the plates. The liquid displacement potential satisfying the boundary conditions is derived and the wet dynamic modal functions of the four plates are expanded by the finite Fourier transformation for a compatibility requirement along the contacting surface between the tank and the liquid. The natural frequencies of the rectangular tank in the wet condition are calculated by using the Rayleigh-Ritz method. The proposed analytical method is verified by observing an excellent agreement with three-dimensional finite element analysis results.


2014 ◽  
Vol 1030-1032 ◽  
pp. 1201-1205
Author(s):  
Hong Ren ◽  
Fan Chun Li ◽  
Tian Yu Zhao

The present work is aimed to free vibration characteristics of marine propeller in fluid, and analyze the influence of fluid inertial effect on propeller. The fully coupled three dimensional finite element method is applied, and the commercial finite element code, ANSYS WORKBENCH, has been used to perform modal analysis for both wet and dry configurations via fluid-structure interaction APDL commands for secondary development. On this basis, analyze a marine propeller in air and in fluid with finite element analysis, then the differences of natural vibration frequencies and vibration modes of the propeller for different boundary conditions are discussed. In addition, the natural frequencies curves are presented. Results show that the natural frequencies of propeller in fluid are significantly lower than those in air, the fluid inertia effect also has some influences on vibration mode.


Author(s):  
Hossein Rokni D. T. ◽  
Abbas S. Milani ◽  
Rudolf J. Seethaler ◽  
Jonathan Holzman

In this study, the natural frequencies and mode shapes of carbon nanotube (CNT) reinforced polymer composite microcantilever beams are investigated by means of a micromechanical model and the three-dimensional finite element analysis. Microcantilever beams are made of Poly vinyl chloride (PVC) and reinforced with multi-wall carbon nanotubes (MWCNTs). MWCNTs can be distributed along the length/width/thickness of the nanocomposite beam. To validate the accuracy and effectiveness of the model, a direct comparison of results is made with an analytical solution for a test case. Next, various material types of the nanocomposite microcantilever beam are introduced and the effect of different distribution patterns and the weight-percents (wt%) of MWCNTs on the first six natural frequencies and mode shapes is found.


2020 ◽  
Vol 103 (4) ◽  
pp. 003685042096954
Author(s):  
Yufei Zhang ◽  
Jingtao Du

Vibration analysis of the classical elastic structures is not only essential for the study of vibration reduction by predicting the dynamic behavior, but also important to ensure a reliable, safe, and lasting structural performance through the proper design procedure. In this paper, the influence of boundary conditions on the free and forced three-dimensional vibration analysis of thick rectangular plates has been performed using the improved Fourier series method. For the elastically restrained thick rectangular plate, the three-dimensional improved Fourier series displacement forms are used to model the vibration field. The energy formula is employed to describe the three-dimensional dynamics of the plate. All the unknown Fourier series coefficients are then solved by the Rayleigh-Ritz method. In order to validate the proposed model, several numerical examples are provided and compared against the results from the literature and Finite Element Analysis (FEA). In addition, the effects of the boundary restraining spring stiffness and the thickness ratios of thick rectangular plates are analyzed under elastically restrained boundary conditions to develop an in-depth understanding of the three-dimensional vibration characteristics of thick rectangular plates.


2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


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