Maximizing the Natural Frequencies and Transverse Stiffness of Centrally damped, Circular Disks by Thickening the Clamped Part of the Disk

Abstract

The natural frequencies and transverse stiffness of centrally damped, circular disks are computed taking into account the flexibility of the central clamp and the thickness of the damped part of the disk. When compared to experimental vibration data, these predictions are more accurate than the traditional, perfect clamping predictions, particularly, for zero and one-nodal-diameter vibration modes. The reduction in natural frequency or transverse stiffness caused by clamping flexibility can be mitigated either by increasing the clamping stiffness or by increasing the hub thickness, defined here as the thickness of the disk sandwiched by the central clamp. A design study of these two alternatives for both stationary and rotating disks shows that increasing the hub thickness is often a more attractive design alternative.