Numerical Simulations of the Head-disk Interface in Hard Disk Drives: Finite Element Solutions for the Transient and Steady State Air-bearing Equations

This monograph is based on the Doctoral thesis of the author at the University of California, Berkeley (2008). Over the past few years, hard disk drives (HDD) have become viable for many consumer products that require large storage capacities. These applications subject the HDD to adverse conditions wherein the reliability and performance of the drive becomes critical. This book presents a Finite Element based simulation methodology which is used to study dynamic events such as load/unload and shock of the HDD. The dynamics of the HDI are governed by the structural components of the HDD as well as the air-bearing which is formed between the spinning disk and the flying head. A new numerical scheme is presented to solve the resulting nonlinear coupled set of equations using stabilized finite elements, first for the steady state case and then for the time dependent case. Meshing/refinement strategies are explored in order to obtain accurate results with as few degrees of freedom as possible. Finally the methodology is applied to simulate the shock and load/unload processes in HDDs and carry out parametric studies on the performance of a 1" HDD.