Versatile disk-drive shock tester

摘要

There has been a trend toward greater shock robustness of disk drives because of the newer more demanding applications and requirements imposed on disk drives. A disk-drive shock tester was developed for the purposes of quickly developing fragility curves for a variety of disk drives, while simultaneously allowing for a detailed experimental investigation of the causes for failure that are due to shock. The design objectives for this shock tester were that translational and rotational shock inputs could be imparted to the disk drives in any direction; the shock pulse widths and amplitudes could be controlled over a very broad range; and a laser Doppler vibrometer or equivalent device could be used in concert with the tester. This paper discusses the design procedure used to develop the tester. This tester has been used to examine the failure modes of disk drives when subjected to non operational shocks with pulse widths varying from 0.5 ms to 2 ms and amplitudes of up to 600 g. Shock fragility curves for various models of disk drives subjected to nonoperational shocks in the y, z, and rotational directions have been generated. Time-domain and frequency-domain comparisons of shock inputs from the tester have been made with those of the industry standard half-sine-wave testers and with those experienced by disk drives during actual handling.