On the oscillation at the final stages of rolling of a hard sphere on an elastic base : J. Halaunbrenner and P. Sukiennik, J. Basic Eng., Sept. 1965, in press; ASME Paper No. 64-Lub-5; 4 figs., 1 table, 9 refs. (See also Wear, 8 (1965) 30.)

Abstract

The mean separations for tin, aluminium and silver rough surfaces pressed beneath a horizontal flat silver-steel anvil by high loads, disagreed with predictions from Tsukizoe and Hisakado theory, which incorrectly assumes that the real contact area equals the applied pressure P divided by the micro-hardness M of the softer contacting material. The point of initial contact (or zero penetration) corresponded to the truncation of surface heights at t = 3.5, for surfaces having Gaussian distributions, where t is the statistical probability function.At high loads, the real contact area as calculated from experimental separation data, corroborated values obtained from profilometry but disagreed with predictions from classical plastic deformation theory. The real area of contact equalled K (PM)m, where K and m are constants which take different values for each of three load ranges.For plastic deformations, the assumption that the relation between the contact area and the separation can be obtained directly from the bearing area curve can be in error by up to 20% at high loads fi.e. for PM >5 × 10−2.