Finite Element Analysis of a Computer Hard Disk Drive Under Shock

Abstract

Shock of computer hard disk drives (HDD) in both portable and desktop computers is a common problem. Shock of an HDD can occur during installing the HDD into the computer, HDD testing, HDD handling, and so forth. It is important to identify key design parameters to improve HDD shock performance. This paper presents the finite element studies of a HDD under a non-operational linear drop shock. A complete HDD model is built in ANSYS finite element package. GP commands are used to apply the preload and define the interface between the head and the disk. Shock pulses with different amplitudes and pulse widths are applied to the HDD. The minimum shock amplitude required to lift off the head from the disk is determined for different shock pulse width. Discrete Fourier Transform studies are used to identify critical frequency ranges for different shock pulse widths. The design guideline for the minimum space required between the swage plates and the disk is provided. The effects of drive base stiffness, disk thickness, actuator arm stiffness, and bearing stiffness on HDD shock performance are investigated.