The Effect of Carbon Nanotubes on the Natural Frequencies of Microcantilever Beams

2010 ◽  
Author(s):  
Hossein Rokni D. T. ◽  
Abbas S. Milani ◽  
Rudolf J. Seethaler ◽  
Jonathan Holzman
Keyword(s):  
Carbon Nanotubes ◽  
Natural Frequencies ◽  
Micromechanical Model ◽  
Three Dimensional ◽  
Distribution Patterns ◽  
Mode Shapes ◽  
Test Case ◽  
Element Analysis ◽  
Multi Wall Carbon Nanotubes ◽  
Three Dimensional Finite Element

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.

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
Keyword(s):  
Hydrostatic Pressure ◽  
Natural Frequencies ◽  
Ritz Method ◽  
Three Dimensional ◽  
Rayleigh Quotient ◽  
Rectangular Plates ◽  
Element Analysis ◽  
Displacement Potential ◽  
Fluid Displacement ◽  
Three Dimensional Finite Element

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.

Modal Analysis of Marine Propeller Submerged in Fluid

2014 ◽  
Vol 1030-1032 ◽  
pp. 1201-1205
Author(s):  
Hong Ren ◽  
Fan Chun Li ◽  
Tian Yu Zhao
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Three Dimensional ◽  
Secondary Development ◽  
Marine Propeller ◽  
Fluid Inertia ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

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.

All-on-4 Concept: A 3-Dimensional Finite Element Analysis

2015 ◽  
Vol 41 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Gianpaolo Sannino
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Distribution Patterns ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Biomechanical Behavior ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element

The aim of this work was to study the biomechanical behavior of an All-on-4 implant-supported prosthesis through a finite element analysis comparing 3 different tilt degrees of the distal implants. Three-dimensional finite element models of an edentulous maxilla restored with a prosthesis supported by 4 implants were reconstructed to carry out the analysis. Three distinct configurations, corresponding to 3 tilt degrees of the distal implants (15°, 30°, and 45°) were subjected to 4 loading simulations. The von Mises stresses generated around the implants were localized and quantified for comparison. Negligible differences in von Mises stress values were found in the comparison of the 15° and 30° models. From a stress-level viewpoint, the 45° model was revealed to be the most critical for peri-implant bone. In all the loading simulations, the maximum stress values were always found at the neck of the distal implants. The stress in the distal implants increased in the apical direction as the tilt degree increased. The stress location and distribution patterns were very similar among the evaluated models. The increase in the tilt degree of the distal implants was proportional to the increase in stress concentration. The 45° model induced higher stress values at the bone-implant interface, especially in the distal aspect, than the other 2 models analyzed.

scholarly journals Nonlinear Analysis of Tie Confined Columns

2020 ◽  
Vol 3 (1) ◽  
pp. 130-138
Author(s):  
Ranajay Bhowmick
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Distribution Patterns ◽  
Complex Stress ◽  
Element Analysis ◽  
Suitable Material ◽  
Dimensional Finite Element ◽  
Static And Dynamic Loads ◽  
Three Dimensional Finite Element ◽  
Concentric Loading

Columns, being a very important component of the building structure, are required to be strong enough and also sufficiently deformable to withstand all possible static and dynamic loads to maintain the integrity of the structure throughout their entire life. The strength and the deformability of the columns can be increased by confining the concrete with lateral reinforcements provided in the form of the spirals, hoops or ties. Several experimental and analytical studies have been carried out by various researchers over the years to determine the extent of improvement that can be made to the strength and ductility of the columns, subjected to concentric loading, by confining them using lateral reinforcements. In the present study three-dimensional finite element models of confined concrete columns have been made using ANSYS and analyzed under the application of static concentric loading to find out the effects of lateral confinement. Suitable material models for both concrete and steel have been chosen and nonlinear finite element analysis (FEA) of laterally confined three-dimensional concrete column models have been carried out. The numerical methodology, at first, has been verified against previous experimental results. Then different types of lateral confinements have been modeled and the stress-strain responses and the complex stress distribution patterns have been studied and compared to find out the better type of confinement.

Three Dimensional Finite Element Analysis of Transverse Free Vibration of Self-Pierce Riveting Beam

2007 ◽  
Vol 344 ◽  
pp. 647-654 ◽  
Author(s):  
Xiao Cong He ◽  
Ian Pearson ◽  
Ken W. Young
Keyword(s):  
Finite Element ◽  
Young’S Modulus ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Self-pierce riveting (SPR) is nowadays widely used in the car manufacturing industry where aluminium alloys are used for body construction. For the design of mechanical structures, formed by the joining of component parts, a knowledge of the vibration characteristics of different joint types (adhesive bonding, spot welding, SPR etc) is essential. The free transverse vibration characteristics of single lap-jointed encastre SPR beams are investigated theoretically in this paper using the three dimensional finite element method (FEM). Numerical examples are provided to show the influence on the natural frequencies, natural frequency ratios and mode shapes of these beams caused by variations in the material properties (E and υ) of the sheet material. It is shown that the transverse natural frequencies of single lap jointed encastre SPR beams increases significantly as the Young’s Modulus of the sheets increases, but only slight changes are encountered for variations of Poisson’s Ratio. It is found that an exponential curve gives an acceptable fit to the relationship between natural frequency and Young’s Modulus. As expected, odd modes shapes were found to be symmetrical about the mid-length position and even modes were anti-symmetrical.

Modal and harmonic analysis of three-dimensional wind turbine models

2016 ◽  
Vol 40 (6) ◽  
pp. 518-527 ◽  
Author(s):  
Takwa Sellami ◽  
Hanen Berriri ◽  
A Moumen Darcherif ◽  
Sana Jelassi ◽  
M Faouizi Mimouni
Keyword(s):  
Finite Element ◽  
Wind Turbine ◽  
Natural Frequencies ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Dynamic Responses ◽  
Mode Shapes ◽  
Element Analysis ◽  
Micro Turbine

In this article, the dynamic responses of wind turbine systems are analytically and numerically investigated. For this purpose, analytic differential equations of motion of wind turbine components subjected to vibration (the blades, the nacelle, and the tower) are solved. This allows determining their dynamic characteristics, mode shapes, and natural frequencies. Two models of two three-dimensional (3D) micro-turbine that are created by the finite element method are set up using the new version of the academic finite element analysis software ANSYS. The first wind turbine is a standard micro three-bladed turbine and the second one is a micro six-bladed Rutland 504. Their natural frequencies and mode shapes are identified based on the modal analysis principle to check the validity of designed models. Dynamic behaviors at several operating conditions of wind turbines are established. Then, spectrum graphs of the structures along x-, y- and z-axis are analyzed.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

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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