Numerical Contact Analysis of Transversely Isotropic Coatings: A Cylinder Within a Circumferential Groove

2000 ◽  
Vol 123 (2) ◽  
pp. 436-440 ◽  
Author(s):  
Clint Morrow, ◽  
Michael Lovell, ◽  
Zhi Deng
Keyword(s):  
Finite Element ◽  
Normal Load ◽  
Transversely Isotropic ◽  
Element Model ◽  
Contact Length ◽  
Operating Conditions ◽  
Circumferential Groove ◽  
Approach Distance ◽  
Dimensional Finite Element ◽  
Coating Parameter

The contact characteristics of transversely isotropic coatings are investigated for a cylinder within a circumferential groove using a two-dimensional finite element model. With the model, contact behavior is evaluated at more than 400 operating conditions by varying coating material, coating thickness, normal load, and cylinder/groove radii. Based on the finite element results, numerical expressions are derived for the maximum surface pressure, contact length, and approach distance as a function of a transversely isotropic coating parameter, ζ. The importance of these expressions, as related to design and the selection of materials for reducing wear in contacting surfaces, is subsequently discussed.

On the Frictional Characteristics of Ball Bearings Coated With Solid Lubricants

1999 ◽  
Vol 121 (4) ◽  
pp. 761-767 ◽  
Author(s):  
M. R. Lovell ◽  
M. M. Khonsari
Keyword(s):  
Finite Element ◽  
Friction Force ◽  
Normal Load ◽  
Transversely Isotropic ◽  
Solid Lubricants ◽  
Operating Conditions ◽  
Hertzian Contact ◽  
Ball Bearings ◽  
Normal Contact ◽  
Low Speed

The problem of a ball bearing in normal contact between two transversely isotropic coated substrates is investigated using the finite element method (FEM). A three-dimensional finite element model is developed that accurately determines the steady friction force in low-speed bearing systems containing soft layered solid lubricant films. Extensive numerical results, which are verified using Hertzian contact theory and laboratory experiments, are obtained at 540 operating conditions by varying coating material, coating thickness, normal load, ball material, and ball radius. Friction force results generated from the FEM are normalized by introducing the dimensionless transversely isotropic coating parameter, ξ. A numerical expression for the normalized friction force in coated ball bearings is determined by curvefitting the results of the 540 simulations performed. The relevance of such an expression, as related to the durability of low-speed bearings, is subsequently ascertained and discussed.

scholarly journals Refractive changes of a new asymmetric intracorneal ring segment with variable thickness and base width: A 2D finite-element model

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257222
Author(s):  
Gonzalo García de Oteyza ◽  
Juan Álvarez de Toledo ◽  
Rafael I. Barraquer ◽  
Sabine Kling
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Transversely Isotropic ◽  
Element Model ◽  
Good Alternative ◽  
Corneal Tissue ◽  
Dimensional Finite Element ◽  
Ring Segment ◽  
Robust Parameter ◽  
Base Width

Purpose To evaluate the local geometric effects of a unilateral intrastromal ring segment with a combined variation of ring thickness and base width in a finite element simulation, and to compare it against the isolated effect of thickness or base width variation alone. Methods A two-dimensional finite-element model of a transversely isotropic cornea was created assuming either axisymmetric stress or plane strain condition. The model geometry was composed of a three-layered corneal tissue (epithelium, anterior and posterior stroma) fixed at the limbus. The implantation of a triangular-shape asymmetric ring segment with varying ring thickness (150 to 300 μm) and base width (600 to 800 μm) was simulated. Also, changes induced by thickness or base width alone were studied and compared their combined effect in the asymmetric ring segment. Geometrical deformation of the simulated cornea and sagittal curvature were the main parameters of study. Results Increasing ring thickness and base width along the arc of the asymmetric ring segment produced a more pronounced flattening in this part of the ring. The asymmetric design did find a good balance between maximizing corneal flattening at one end and minimizing it at the other end, compared to the isolated effect of ring thickness and width. Ring thickness was the most robust parameter in flattening both, the central and peripheral cornea. Conclusion The finite-element model permitted a theoretical study of corneal deformation undergoing implantation of realistic and hypothetical ring geometries. Intracorneal asymmetric ring segments with varying thickness and base width can be a good alternative in corneas with asymmetric keratoconus phenotypes.

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.

Mechanical Simulation of Knee Movement in Basketball Shooting

2013 ◽  
Vol 336-338 ◽  
pp. 760-763
Author(s):  
Hui Yue
Keyword(s):  
Finite Element ◽  
Cruciate Ligament ◽  
Three Dimensional ◽  
Element Model ◽  
Basketball Player ◽  
Knee Movement ◽  
Dimensional Finite Element ◽  
Anterior Cruciate ◽  
Three Dimensional Finite Element

A short explanation of the finite element method as a powerful tool for mathematical modeling is provided, and an application using constitutive modeling of the behavior of ligaments is introduced. Few possible explanations of the role of water in ligament function are extracted from two dimensional finite element models of a classical ligament. The modeling is extended to a three dimensional finite element model for the human anterior cruciate ligament. Simulation of ligament force in pitching motion of basketball player is studied in this paper.

Sign in / Sign up

Export Citation Format

Share Document