On the Mechanism of Contact between Solid Surfaces : 2nd Report, The Real Area of Contact, the Separation and the Penetrating Depth

Assuming that the asperities on normally distributed surface are cones of the same slope that depends on the surface roughness, it is deduced theoretically by the slip-line theory that the real area of contact in the case of contact between a soft conical asperity and a hard flat surface or between a hard conical asperity and a soft flat surface depends on the slopes of the conical asperities, the coefficient of friction at the interface of contact asperities, and the flow pressure. If the real area of contact is corresponding to the geometrical area obtained immediately from the bearing-area curve, the relation between the real area of contact and the separation or the penetrating depth is also obtained theoretically. A comparison of calculated values based on this theory with experimental data shows good agreement.