Statistical Analysis of Perfect Contact and Wear Durability Conditions of a Single-Degree-of-Freedom Contact Slider

Abstract

In this paper, the design condition of a single-degree-of-freedom (1DOF) contact slider over a random wavy surface of a disk is analyzed statistically. It is numerically confirmed that when the slider is in contact with a disk, spacing variation histograms are close to Gaussian even if surface waviness histogram is not close to Gaussian. The design condition of the slider and the surface waviness necessary for perfect contact sliding is derived from 3σs<δ, where σs and δ are the standard deviation of spacing variation and the static penetrating depth, respectively, and it is verified both numerically and experimentally. The necessary condition for wear durability under uniform contact pad pressure is also derived. An example of the slider-to-disk interface design which satisfies both perfect contact sliding and wear durability is shown. In order to evaluate σs adequately, frequency response of slider must be integrated over the range from fr/2 to 2 fr where fr is the contact resonance frequency. It is found that a disk surface should be extremely smooth to satisfy both the perfect contact sliding and wear durability conditions. [S0742-4787(00)03001-0]