THE EFFECTS OF BASEPLATE WARPAGE AND SKEW ON THE CONFIGURATION OF A SPINNING FLEXIBLE DISK

The behavior of a flexible disk, spinning in close proximity to a warp ed/skewed stationary baseplate, is investigated. The governing partial differential equation for the disk deflection is coupled to the Reyno lds equation of the air film. Four warped/skewed baseplate configurati ons are modeled. The effects of baseplate warpage and skew on the stea dy-state configuration of the disk are determined by investigating sma ll deviations away from the axisymmetric configuration of the disk cor responding to a perfect baseplate. Exponential Fourier series expansio ns in the circumferential direction, along with finite differences in the radial direction, are used. Numerical results are determined and c ompared for various values of the angular velocity and initial thickne sses of the air film. Among the three warpages considered, the saddle warped baseplate provides the largest change in disk deflection wherea s the spherically warped baseplate gives the smallest change. The tota l response of the disk is obtained by superposition of the deflection change caused by the warped/skewed baseplate and the deflection obtain ed from the axisymmetric solution.