Numerical Analysis of Contact Mechanics between a Spherical Sliderand a Flat Disk with Low Roughness Considering Lennard–Jones Surface Forces

2011 ◽  
pp. 3-24
Author(s):  
Kyosuke Ono
Keyword(s):  
Numerical Analysis ◽  
Contact Mechanics ◽  
Surface Forces ◽  
Lennard Jones ◽  
Flat Disk

Numerical Analysis Method of Contact Mechanics Between a Sphere and a Flat Considering Lennard-Jones Surface Forces of Contacting Asperities and All Rough Height Surfaces

2011 ◽  
Author(s):  
Kyosuke Ono
Keyword(s):  
Numerical Analysis ◽  
Contact Mechanics ◽  
Present Theory ◽  
Adhesive Contact ◽  
Surface Forces ◽  
Asperity Contact ◽  
Analysis Method ◽  
Surface Theory ◽  
Numerical Analysis Method ◽  
Lennard Jones

A new numerical analysis method for elastic adhesive contact mechanics between a sphere and a flat with a sub-nanometer roughness is presented. In contrast to conventional theories, the elastic deformations of both contacting asperities and mean height surface and Lennard-Jones (LJ) surface forces of both contacting asperities and all rough surfaces including valley areas are taken into account New adhesive force of contacting asperity is used from asperity contact analysis. Calculated results for head-disk asperity contact with current low roughness are shown in comparison with conventional theories. The relationship among present theory, mean height surface theory and perfectly smooth surface theory is discussed.

Numerical Method of Analyzing Contact Mechanics between a Sphere and a Flat Considering Lennard-Jones Surface Forces of Contacting Asperities and Noncontacting Rough Surfaces

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Kyosuke Ono
Keyword(s):  
Numerical Method ◽  
Contact Mechanics ◽  
Rough Surfaces ◽  
Present Theory ◽  
Adhesive Contact ◽  
Adhesive Force ◽  
Surface Forces ◽  
Contact Theory ◽  
Magnetic Disk ◽  
Lennard Jones

A new numerical method of analyzing adhesive contact mechanics between a sphere and a flat with sub-nanometer roughness is presented. In contrast to conventional theories, the elastic deformations of mean height surfaces and contacting asperities, and Lennard-Jones (LJ) surface forces of both the contacting asperities and noncontacting rough surfaces including valley areas are taken into account. Calculated contact characteristics of a 2-mm-radius glass slider contacting a magnetic disk with a relatively rough surface and a 30-mm-radius head slider contacting a currently available magnetic disk with lower roughness are shown in comparison with conventional adhesive contact theories. The present theory was found to give a larger adhesive force than the conventional theories and to converge to a smooth sphere-flat contact theory as the roughness height approaches zero.

Numerical Method of Analyzing Contact Mechanics Between a Sphere and a Flat Considering Lennard-Jones Surface Forces of Contacting Asperities and Mean Height Surfaces

2010 ◽  
Author(s):  
Kyosuke Ono
Keyword(s):  
Contact Mechanics ◽  
Adhesion Force ◽  
Surface Forces ◽  
Elastic Contact ◽  
Analysis Method ◽  
Elastic Deformations ◽  
Magnetic Disk ◽  
Head Slider ◽  
Lennard Jones ◽  
Relaxation Iteration

A numerical analysis method for elastic contact mechanics between a sphere and a flat with a sub-nanometer roughness is presented by taking account of Lennard-Jones (LJ) surface forces. In contrast to conventional theories, the elastic deformations and LJ surface forces of both mean surfaces and contacting asperities are taken into account. Convergent solutions obtained by a simple under-relaxation iteration method are discussed for 2-mm radius glass slider and 20-mm radius head slider contacting with a magnetic disk. It is found that the increase in adhesion force with a decrease in surface roughness can be suppressed by deceasing asperity radius and increasing asperity density.

Numerical analysis of hemivariational inequalities in contact mechanics

Acta Numerica ◽  
2019 ◽  
Vol 28 ◽  
pp. 175-286 ◽  
Author(s):  
Weimin Han ◽  
Mircea Sofonea
Keyword(s):  
Numerical Analysis ◽  
Mathematical Models ◽  
Contact Mechanics ◽  
Numerical Solutions ◽  
Deformable Body ◽  
Industrial Process ◽  
Contact Problems ◽  
Hemivariational Inequalities ◽  
Uniqueness Results ◽  
Simulation Results

Contact phenomena arise in a variety of industrial process and engineering applications. For this reason, contact mechanics has attracted substantial attention from research communities. Mathematical problems from contact mechanics have been studied extensively for over half a century. Effort was initially focused on variational inequality formulations, and in the past ten years considerable effort has been devoted to contact problems in the form of hemivariational inequalities. This article surveys recent development in studies of hemivariational inequalities arising in contact mechanics. We focus on contact problems with elastic and viscoelastic materials, in the framework of linearized strain theory, with a particular emphasis on their numerical analysis. We begin by introducing three representative mathematical models which describe the contact between a deformable body in contact with a foundation, in static, history-dependent and dynamic cases. In weak formulations, the models we consider lead to various forms of hemivariational inequalities in which the unknown is either the displacement or the velocity field. Based on these examples, we introduce and study three abstract hemivariational inequalities for which we present existence and uniqueness results, together with convergence analysis and error estimates for numerical solutions. The results on the abstract hemivariational inequalities are general and can be applied to the study of a variety of problems in contact mechanics; in particular, they are applied to the three representative mathematical models. We present numerical simulation results giving numerical evidence on the theoretically predicted optimal convergence order; we also provide mechanical interpretations of simulation results.

Boundary Lubrication and Its Stability

2008 ◽  
Author(s):  
Kamaljit Singh ◽  
Saurabh Baghmar ◽  
Jagdish Sharma ◽  
M. V. Khemchandani ◽  
Q. J. Wang
Keyword(s):  
Solid Surface ◽  
Boundary Lubrication ◽  
Surface Forces ◽  
Aluminum Surface ◽  
Boundary Lubrication Friction ◽  
Lennard Jones ◽  
Boundary Lubricant ◽  
Zone Of Influence ◽  
En 31 ◽  
Experimental Values

The interaction between lubricant molecules and the solid surface to be lubricated depends upon the surface forces which can be attractive, and repulsive. It thus forms an interactive zone above the solid surface having a band width and height of surface potential and is considered as ‘Zone of Influence’-(ZOI). Its value will vary with the nature of surface finish, distribution of alloying constituents on surface matrix and its size which play very important role in prediction of stability and failure of boundary lubrication friction including absorption and desorption of lubricant molecules. A theoretical model for the formation of boundary lubrication is proposed by combining Lennard Jones (6–12) potential to incorporate for estimating the critical temperature of boundary lubricant, friction coefficient and variation of ZOI for a given condition. Experimental values using EN 31 Ball sliding against the aluminum surface with 0.4% stearic acid as lubricant data agrees well with theoretical values.

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