Influence of a Hard Surface Layer on the Limit of Elastic Contact—Part I: Analysis Using a Real Surface Model

A numerical simulation technique for calculating the pressure distribution and the deformed geometry of an elastic half space which has a hard surface layer in contact with a rigid indenter with a rough surface is presented. In order to reduce the computing time, the Conjugate Gradient Method ( CGM ) is applied to solve a set of linear equations for unknown pressures. In each iteration of the CGM, the Fast Fourier Transform (FFT) is used for the task of multiplying a direction vector by an influence coefficient matrix. An FFT-based scheme for evaluating subsurface stresses in the layer and the substrate is also presented. As an example, the pressure distribution and the deformed geometry of a steel surface coated with a TiN layer in contact with a rigid rough indenter are calculated. The subsurface stresses are also compared with von Mises yield criterion to investigate the deformation mode at the asperity contacts. The results show that the limit of elastic contact is highly dependent on the layer thickness and the surface roughness.

[1]  N. Suh,et al.  The role of hard layers in lubricated and dry sliding , 1987 .

[2]  R. S. Sayles,et al.  Numerical Contact Model of a Smooth Ball on an Anisotropic Rough Surface , 1994 .

[3]  B. Bhushan,et al.  A Numerical Three-Dimensional Model for the Contact of Rough Surfaces by Variational Principle , 1996 .

[4]  R. S. Sayles,et al.  A Numerical Model for the Elastic Frictionless Contact of Real Rough Surfaces , 1986 .

[5]  M. Hestenes,et al.  Methods of conjugate gradients for solving linear systems , 1952 .

[6]  R. S. Sayles,et al.  A Numerical Model for the Contact of Layered Elastic Bodies With Real Rough Surfaces , 1992 .

[7]  E. Ioannides,et al.  A Fast Solution of the Dry Contact Problem and the Associated Sub-Surface Stress Field, Using Multilevel Techniques , 1991 .

[8]  R. King,et al.  Sliding Contact Stress Field Due to a Spherical Indenter on a Layered Elastic Half-Space , 1988 .

[9]  R. Winther.  Some Superlinear Convergence Results for the Conjugate Gradient Method , 1980 .

[10]  J. Greenwood,et al.  Contact of nominally flat surfaces , 1966, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[11]  E. O. Brigham,et al.  The Fast Fourier Transform , 1967, IEEE Transactions on Systems, Man, and Cybernetics.

[12]  R. S. Sayles,et al.  Paper VIII(i) A 3-dimensional method of studying 3-body contact geometry and stress on real rough surfaces , 1987 .

[13]  Ning Ren,et al.  Contact Simulation of Three-Dimensional Rough Surfaces Using Moving Grid Method , 1993 .

[14]  T. R. Thomas,et al.  Measurements of the Statistical Microgeometry of Engineering Surfaces , 1979 .

[15]  K. Johnson.  Contact Mechanics: Frontmatter , 1985 .

[16]  R. S. Sayles,et al.  Effect of Roughness and Sliding Friction on Contact Stresses , 1991 .

[17]  H. Hintermann.  Adhesion, friction and wear of thin hard coatings , 1984 .

[18]  Liang Xian,et al.  A numerical model for the elastic contact of three-dimensional real rough surfaces , 1991 .

[19]  L. E. Goodman,et al.  The Stress Field Created by a Circular Sliding Contact , 1966 .

[20]  J. W. Kannel,et al.  Analyses of the Role of Surface Roughness on Contact Stresses Between Elastic Cylinders With and Without Soft Surface Coating , 1989 .