The primary goal of this research project is to investigate the local and global dynamics in the motion of a spinning disc system and to numerically and experimentally verify the theoretical results. The results of this research will be useful in applications such as computer disc memory devices, industrial circular saw blades, and turbine rotor dynamics. The objectives of the research are four-fold. First, the general nonlinear equations of motion governing the disc dynamics will be derived systematically to include the effects due to inherent bending rigidity, membrane stresses arising from centrifugal forces, non-axismmetry of the inplane and transverse displacements, geometric nonlinearities, aerodynamic damping arising from air stationary and moving with respect to the disc, parametric excitation due to time varying spring rate, etc.. Second, is equations, along with symmetry-breaking bifurcations, will also be examined. Third the mechanisms which five rise to global bifurcations in nonlinear spinning disc to identify the important modes, locate the stability boundaries, and examine the nature of the nonlinear response to verity the theoretical predictions. Validation studies will be carried out using actual data from manufacturers of spinning discs. Experimental verification and validation in turn, guide the development and refinement of the theories to incorporate any new phenomena observed.
