1. For rectangular plates having Nx and N con-5 t m t and NXy = 0, there i s essentially noycomplication, in principle, t o the numerous solutions that exist for unloaded rectangular plates. example, the mode shapes for SS-8s-88-SS
2. Some solutions exist for circular plates having thickn 5&3,ygriation in the radial direction only. Conway showed that for plates having flexural rigidities varying according to D = Dorm, where 0 and m are ConstantS, the solution of the differegtial equation can he considerably simplified provided Poisson's ratio i s restricted t o v = (2m-3)/9. In this manner exact solutions were obtained in Ref. 360 for the axisymnetric modes of clamped plates having m = 2 (v = l/9), m = 3 (v = 1/3), and m = 1811 (v = 5/21). It i s interesting to note that for variable thickness circular plates the frequency parameters depend upon Poi=.son's ratio for clamped boundary conditions as well as others. In Ref. 362 the work described above was extended t o annular plates of linearly varying thickness (i.e., m =3,> = 113) which are clamped on both the inner and outer boundaries. Also examined was the solid circular plate which has a linearly varying thickness in the interval b < r 5 a and a constant thickness in the interval 0 5 r 5 b and i s clamped along i t s edge.
3. A series;Ref