Roughness Effects on Dynamic Response of High Density Disk Drives under High Knudsen Number

Abstract

Finite element method is used in this paper to analyze the air bearing characteristics and structural mechanics response in an integrated mathematical model. Galerkin's method is used to set up the finite element model for the modified Reynolds equation of the ultra-thin gas bearing. The slider-suspension-air bearing system is simulated and the roughness effects are taken into account. An analytical model to describe the disk surface topography is introduced and the roughness directional pattern can be expressed by a parameter. Simulation results show that the roughness is helpful to resist the slider divergent response and that the response time of the slider operating over a rough surface is shorter than that over a smooth surface. With the increase of the ratio of the minimum film thickness to the standard deviation of the composite roughness height the effects of the roughness directional pattern on the dynamic response of the slider can be neglected compared with the effects of the roughness height. Presented at the 55th Annual Meeting Nashville, Tennessee May 7–11, 2000