Frequency and Stability Analysis Method of Asymmetric Anisotropic Rotor-Bearing System Based on Three-Dimensional Solid Finite Element Method

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Ma Wei Meng ◽  
Wang Jian Jun ◽  
Wang Zhi
Keyword(s):  
Finite Element ◽  
Differential Equations ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Frequency Characteristics ◽  
Analysis Method ◽  
Rotor Bearing ◽  
Finite Element Procedure ◽  
Linear Differential ◽  
3D Solid

An efficient analysis method is suggested to investigate the frequency characteristics and stability of asymmetric anisotropic rotor-bearing systems. Modifications are made to incorporate the effect of stator asymmetry into an existing three-dimensional (3D) solid finite element procedure developed for rotors with symmetric supports. The reduced ordered linear differential equations with periodic coefficients of the asymmetric anisotropic rotor model are established in the rotating frame. The frequency characteristics and stability of the obtained periodic time-varying coefficient differential equations are investigated based on Floquet theory and Hill's method. Numerical examples and experimental studies are presented to validate the effectiveness of the presented method.

scholarly journals Evaluation of the Effects of the Chincup Appliance on the Craniofacial Structures by the Finite Element Analysis

2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Fe Model ◽  
Analysis Method ◽  
Class Iii ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Clinical Changes

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.

A Biomechanical Model of Lumbar Spine

2000 ◽  
Author(s):  
Subramanya Uppala ◽  
Robert X. Gao ◽  
Scott Cowan ◽  
K. Francis Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Element Model ◽  
Fe Model ◽  
Flexion Extension ◽  
Cortical Shell ◽  
Three Dimensional Finite Element

Abstract The strength and stability of the lumbar spine are determined not only by the bone and muscles, but also by the visco-elastic structures and the interplay between the different components of the spine, such as ligaments, capsules, annulus fibrosis, and articular cartilage. In this paper we present a non-linear three-dimensional Finite Element model of the lumbar spine. Specifically, a three-dimensional FE model of the L4-5 one-motion segment/2 vertebrae was developed. The cortical shell and the cancellous bone of the vertebral body were modeled as 3D isoparametric eight-nodal elements. Finite element models of spinal injuries with fixation devices are also developed. The deformations across the different sections of the spine are observed under the application of axial compression, flexion/extension, and lateral bending. The developed FE models provided input to both the fixture design and experimental studies.

Finite Element Modeling of Hard Roller Burnishing: An Analysis on the Effects of Process Parameters Upon Surface Finish and Residual Stresses

2007 ◽  
Vol 129 (4) ◽  
pp. 705-716 ◽  
Author(s):  
Partchapol Sartkulvanich ◽  
Taylan Altan ◽  
Francisco Jasso ◽  
Ciro Rodriguez
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Process Parameters ◽  
Surface Finish ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Cost Effective ◽  
Machined Surface ◽  
Fem Model ◽  
Roller Burnishing

Hard roller burnishing is a cost-effective finishing and surface enhancement process where a ceramic ball rolls on the machined surface to flatten the roughness peaks. The ball is supported and lubricated by hydrostatic fluid in a special tool holder. The process not only improves surface finish but also imposes favorable compressive residual stresses in functional surfaces, which can lead to long fatigue life. Most research in the past focused on experimental studies. There is still a special need for a reliable finite element method (FEM) model that provides a fundamental understanding of the process mechanics. In this study, two-dimensional (2D) and three-dimensional FEM models for hard roller burnishing were established. The developed 2D FEM model was used to study the effects of process parameters (i.e., burnishing pressure, feed rate) on surface finish and residual stresses. The simulation results were evaluated and compared to the experimental data. Results show that the established FEM model could predict the residual stresses and provided useful information for the effect of process parameters. Both FEM and experiments show that burnishing pressure is the most influence, where high burnishing pressure produces less roughness and more compressive residual stress at the surface.

Soret and Dufour Effects on Three Dimensional Upper-Convected Maxwell Fluid with Chemical Reaction and Non-Linear Radiative Heat Flux

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
M. Ramzan ◽  
M. Bilal ◽  
Jae Dong Chung
Keyword(s):  
Heat Flux ◽  
Differential Equations ◽  
Chemical Reaction ◽  
Radiative Heat ◽  
Three Dimensional ◽  
Maxwell Fluid ◽  
Radiative Heat Flux ◽  
Soret And Dufour Effects ◽  
Non Linear ◽  
Linear Differential

Abstract Three dimensional chemically reactive upper-convected Maxwell (UCM) fluid flow over a stretching surface is considered to examine Soret and Dufour effects on heat and mass transfer. During the formulation of energy equation, non-linear radiative heat flux is considered. Similarity transformation reduces the partial differential equations of flow problem into ordinary differential equations. These non-linear differential equations are then solved by using bvp4c MATLAB built-in function. A comparison of the present results with the published work is also included. Effects of some prominent parameters such as Soret and Dufour number, chemical reaction parameter, Prandtl number, Schmidt number and thermal radiation on velocity, temperature and concentration are discussed graphically and numerically. A comparison with the previously published work is also included in a tabular form.

A Novel Finite-Element– Numerical-Integration Model for Composite Laminates Supported on Opposite Edges

2007 ◽  
Vol 74 (6) ◽  
pp. 1114-1124 ◽  
Author(s):  
Tarun Kant ◽  
Sandeep S. Pendhari ◽  
Yogesh M. Desai
Keyword(s):  
Finite Element ◽  
Differential Equations ◽  
Composite Laminates ◽  
Three Dimensional ◽  
Laminated Composite ◽  
Composite Plates ◽  
Coupled System ◽  
Integration Model ◽  
Numerical Integrators ◽  
Support Conditions

An attempt is made here to devise a new methodology for an integrated stress analysis of laminated composite plates wherein both in-plane and transverse stresses are evaluated simultaneously. The method is based on the governing three-dimensional (3D) partial differential equations (PDEs) of elasticity. A systematic procedure is developed for a case when one of the two in-plane dimensions of the laminate is considered infinitely long (y direction) with no changes in loading and boundary conditions in that direction. The laminate could then be considered in a two-dimensional (2D) state of plane strain in x-z plane. It is here that the governing 2D PDEs are transformed into a coupled system of first-order ordinary differential equations (ODEs) in transverse z direction by introducing partial discretization in the finite inplane direction x. The mathematical model thus reduces to solution of a boundary value problem (BVP) in the transverse z direction in ODEs. This BVP is then transformed into a set of initial value problems (IVPs) so as to use the available efficient and effective numerical integrators for them. Through thickness displacement and stress fields at the finite element discrete nodes are observed to be in excellent agreement with the elasticity solution. A few new results for cross-ply laminates under clamped support conditions are also presented for future reference and also to show the generality of the formulation.

scholarly journals A hybrid analytical-numerical solution for a circular pile under lateral load in multilayered soil

2020 ◽  
Vol 14 (1) ◽  
pp. 1-14
Author(s):  
Nghiem Xuan Hien
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Differential Equations ◽  
Numerical Solution ◽  
Elastic Foundation ◽  
Three Dimensional ◽  
Bending Moment ◽  
Lateral Load ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

A hybrid analytical-numerical solution is proposed to solve the problem of a laterally loaded pile with a circular cross-section in multilayered soils. In the pile-soil model, the lateral load is located at the pile head including both lateral force and bending moment. The single pile is considered as a beam on elastic foundation while shear beams model the soil column below the pile toe. The differential equations governing pile deflections are derived based on the energy principles and variational approaches. The differential equations are solved iteratively by using the finite element method that provides results of pile deflection, rotation angle, shear force, and bending moment along the pile and equivalent stiffness of the pile-soil system. The modulus reduction equation is also developed to match the proposed results well to the three-dimensional finite element analyses. Several examples are conducted to validate the proposed method by comparing the analysis results with those of existing analytical solutions, the three-dimensional finite element solutions. Keywords: beam on elastic foundation; finite element method; pile; energy principle; lateral load.

Finite Element Analysis for Cycloid Gear and pin Teeth of FA Cycloid Drive Based on ANSYS

2012 ◽  
Vol 215-216 ◽  
pp. 1197-1200 ◽  
Author(s):  
Lei Lei ◽  
Xiao Chun Shi ◽  
Tian Min Guan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Analysis Method ◽  
Force Analysis ◽  
Element Analysis ◽  
Fem Model ◽  
Contact State ◽  
Analysis Theory ◽  
Calculation Results

In order to validate the force analysis between cycloid gear and pin wheel, the paper built the contact FEM model of between cycloid gear and pin teeth, analyzed statically three-dimensional contact analysis for them and get their contact state. The calculation results coincided with the force analysis method and proved the correctness of the stress analysis theory.

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