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

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.