Three Dimensional Vibration of Disks and Cylinders
Professor J Wickert
Carnegie Mellon University
Annular disks and cylinders are common structural components in
engineering with some applications to rotating machinery including disk
and drum brakes, bladed disk assemblies, and computer disk drives. In
this seminar, the three dimensional vibration of disks and cylinders
having arbitrary dimensions, and either free or constrained boundary
conditions, will be discussed. Natural frequencies and mode shapes are
predicted by discretizing the equations of three dimensional
elastodynamics through the Ritz method, and those results are compared
with laboratory measurements. For appropriate limiting values of the
model's parameters, this treatment encompasses traditional models for
beams, rods, shafts, plates, cylinders, rings, and shells. With a view
towards interesting or unexpected phenomena, the seminar will emphasize
in-plane vibration modes, disk-hat structures, and frequency clusters
that develop for families of radial and longitudinal shear modes.
Implications of the findings for modal testing and forced response will
also be discussed.
