Analysis of Bouncing Vibrations of a 2-DOF Model of Tripad Contact Slider Over a Random Wavy Disk Surface

Abstract

We numerically analyzed the bouncing vibrations of a two-degree-of-freedom (2-DOF) model of a tri-pad contact slider with air bearing pads over a random wavy surface and manifested the design conditions of a contact slider. The effects of the design parameters such as air bearing stiffness, contact damping ratio, the coefficient of friction, and the characteristics of the disk surface waviness on dynamic behavior and the contact sliding ability of the slider have been investigated. As a result, we found that friction force decreases the contact sliding ability at the boundary of the intermittent and continuous contact sliding. We also found that the distance between the rear air bearing center and the contact pad has a significant effect on the contact sliding ability. If the contact pad is apart from the rear air bearing center, the contact pad tends to separate from the disk. Based on this analytical study, we have proposed two design concepts: (1) Make the distance between the rear air bearing center and the contact pad as small as possible; in this case, the larger the rear air bearing stiffness results are, the better the contact ability is; (2) If some distance between the rear air bearing center and the contact pad is inevitable, then make the rear air bearing stiffness much smaller than the contact stiffness.