Dynamic model of hard disk drive (HDD) latch system

The goal of this project is to develop a HDD collision model, and from this model create a simulation tool to predict the impact response of the Head Actuator Assembly (HAA) when a load/unload (L/UL) type Hard Disk Drive (HDD) undergoes a drop test. In the event when the HDD is dropped against a hard surface, the impulse experienced by the HAA may cause it to lift off the ramp and land on the surface of the disk. Under these circumstances, the HDD may fail instantly or degrade over time. Various latch mechanism designs have been introduced to counteract this problem. However, there will still be instances when the latch mechanism fails to engage the HAA. Therefore, the ability to predict the impact response of the HAA is critical in improving the shock robustness of the HDD. In this report, modelling of single rigid bodies collision based on the “impulse-based collision model” method was first introduced. This was followed by modelling of articulated rigid bodies collision. Next, the concepts for these two models were extended to develop a simplified HDD model, consisting of a HDD casing with a HAA, colliding with the ground. To validate the collision models, Excel incorporating Visual Basic was used to program a simulation tool to compute the results. These computed results together with simulation results from a two – dimensional rigid body simulation software, Working Model 2D (WM2D), were then presented.Bachelor of Engineering (Mechanical Engineering