SHOCK-PROOF DESIGN OF HEAD DISK ASSEMBLY SUBJECTED TO IMPULSIVE EXCITATION

This paper reports a study on the transient response of a head disk as sembly (HDA) subjected to a half-sine shock pulse in the axial and pit ching directions. The solution is obtained using the multi-modal expan sion approximation and applying the Galerkin method to the resulting e quations. Numerical results are obtained by the Newmark beta method fo r a 3.5'' hard disk-head system. It is found that the relative distanc e between the head and the disk reduces to the minimum when the input duration tau is about 1.5 times the natural half-period of the fundame ntal (0, 0) mode. Results obtained also show that the shock-proof head satisfies (1/2 pi)(k/m)(1/2)=f(00), where k is the stiffness of the h ead arm, m the head mass and f(00) the (0, 0) mode frequency of the ro tating disk, and that the head slider should be designed so that the a ssembled system of the head and the disk has a high air-film stiffness .