Numerical investigation of fracture of small form factor glass disks as a function of shock level

Disk drives with 27.4 mm diameter disks are currently available commercially and disk form factors below 27.4 mm have recently been proposed. Since these so-called micro drives are to be used mainly in hand-held consumer devices, it is likely that they will experience very high shock levels, on the order of several thousand G´s. Thus, the behavior of disk drives at ultra high shock levels becomes an important factor in the design and analysis of micro drives. In this paper we present numerical results for crack formation in glass disks subject to ultra high shock levels. The results provide design guidelines for the maximum allowable shock levels in small form factor disk drives with glass disks.