Dynamics experiment and analysis of a hard disk drive

The dynamics of a commercially available hard disk drive were investigated using both experimental and numerical techniques. The drive has a storage capacity of 1 GB with two 3 1/2-inch disks. First, each individual component-disk, suspension assembly, actuator arm, and arm coupled with the assembly-was briefly studied. Then, modal experiments were performed on the drive in both states of the disks, stationary or rotating. A finite element (FE) model for studying the dynamics of the drive was created. The model consists of one disk, two actuator arms, and two suspension assemblies. Good correlation between the experiment and FE analysis was achieved. It was shown that the drive exhibits very complicated modal properties and that the actuator arm significantly affects the dynamics of the drive, especially as regards track following of the sliders.