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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 the previous work, it is found that when the disk is more tightly clamped, it helps to decrease the shock response of the disk and then avoid the head slap. In this paper, the real boundary condition of the disk for a small form factor hard disk drive from Seagate is investigated numerically. The disk is clamped between the clamp and the hub. The shock response of the disk under a half-sine acceleration pulse is simulated by using the finite element method. In the finite element model, both contact between disk and clamp and contact between disk and hub are considered. According to the simulation results, how to decrease the shock response of the disk is suggested.

The interest in the effects of shock on HDDs has come into currency due to the reduction of the flying height of the head/disk interface and the increasingly hostile environments encountered in the usage of many consumer electronics and portable devices. This paper discusses the shock pulse amplitude and width effects on the shock response of an operational disk drive. The drive is subjected to half sine acceleration shock pulse with varying amplitude and width. A finite element model of the hard disk drive is developed in the commercially available finite element package, ANSYS/LSDYNA. The air bearing between the disk and the slider is modeled by nonlinear springs. The contact between the disk and the slider is also considered. It is found that the shock response of the drive is sensitive to both the shock pulse amplitude and width.

The use of a pseudodynamic testing method to obtain a response from an impulsive loading may lead to an incorrect test result even though the test setup is properly adjusted and the time step is appropriately chosen based on general considerations. The cause to this problem is analytically explored and a pseudodynamic technique is proposed to overcome this difficulty. The technique is to perform a single small time step immediately upon termination of the applied impulse, while the other time steps can still be conducted by the time step determined from general considerations. The feasibility of this technique is analytically verified and confirmed by a series of pseudodynamic tests for both linear elastic systems and inelastic systems.

This paper analyses the dynamic characteristics of MWMS by optimizing the design of the anvil table to ensure the waveform in allowing limit, simulating the impact of MWMS, and demonstrating the influence of the low-pass filter and the height of hammer drop to test results.