Static and dynamic stability of variable thickness annular plates

The static and dynamic stability of variable thickness annular plates subject to periodic in-plane forces is studied. For this purpose a sector finite element model with the wave propagation technique of cyclic symmetry is developed. Plate thickness is both increased and decreased in the outward radial direction by the equations h = h_max( r r_o)^+λ or h = h_max( r r_i)^-λ respectively. The Mindlin plate finite element model is used to handle both the thick and thin plates. The instability regions are determined for a wide range of excitation frequencies with different boundary conditions by using Bolotin's method with the effect of static forces taken into account.