Passive damping of spinning disks

An investigation of the application of constrained-layer damping to compute r disk drives is presented. Nine constrained-layer disks were manufactured and tested to determine their modal parameters and variations. The eigenval ue realization algorithm was used to extract the natural frequencies and da mping ratios from the nine constrained-layer damped disks and from four sol id aluminum disks. These results provide damping values that will be useful in future stability analyses of spinning disks that include damping. Finit e element models were developed and used to calculate natural frequencies a nd damping ratios for the damped disks. The numerical results are compared to the measured values. The natural frequencies are predicted to within 8%, and the damping ratios are predicted to within 35% of the experimentally d etermined values. The finite element model provides a method to obtain damp ing values and natural frequencies for different layer thicknesses for futu re studies. The results also give an indication of the accuracy expected fr om the finite element results. Finally, the experimental results from spinn ing the constrained-layer damped disks in a disk drive assembly are present ed. The results show that the constrained-layer damping dramatically reduce s the transverse vibrations of the spinning disks in the present configurat ion.