Shock response analysis on thermal stick-slip phenomenon in hard disk drive

We measured and calculated shock responses due to the thermal stick-slip phenomenon in hard disk drives, and visualized the stress wave propagation. We utilized PZT elements and the response envelopes to observe the propagation. Then we calculate the shock response and compared the results with the measurement. We observed that the stress wave propagated from the stick-slip point, through the actuator to the head. Using this calculation model, we demonstrated shock detection investigation using the shock sensors. We compared the sensor responses attached to the base plate with one on the actuator, and found the response on the actuator decreases due to the cushiony property of the pivot bearing. We proposed to use the lower-natural-frequency sensor if the sensor is on the actuator.