FEA Simulation of Linear and Rotary Drop Test for Small Form Factor HDD

As small form factor (one-inch and smaller) hard disk drives are widely used in portable consumer appliances and gadgets, their mechanical robustness is of greater concern. In this paper, the non-operational shock response for the one-inch drive is investigated. A finite element model of the hard disk drive was developed in the commercially available finite element package, ANSYS. The overall model includes the HDD enclosure base, the HSA, the pivot bearing and the disk. The non-operational linear drop test and rotary drop test are simulated using the implicit to explicit analysis function of ANSYS. In linear drop test, a half-sine acceleration pulse is applied to the two short edges of the enclosure base. In rotary drop test, a half-sine acceleration pulse is applied to the impact edge. The translational freedom of the opposite edge, which acts as the rotating axis, is constrained. Both linear drop test and rotary drop test under different amplitude and duration of the half-sine acceleration pulse are simulated. The head slap behavior in these simulations is investigated and compared to identify the most vulnerable drop condition for the HDD