DYNAMIC STIFFENING OF CIRCULAR PLATES AND DETERMINATION OF THEIR BUCKLING, INPLANE PRESSURE

This paper presents some numerical experiments performed on transverse vibrations and the elastic stability of homogeneous, isotropic clampe d circular plates of discontinuously varying thickness. The purpose of the study is threefold: (1) to determine dynamic stiffening situation s; (2) to experiment on the effect of optimization with respect to an exponential parameter (non-integer version of the Rayleigh-Ritz method or the 'optimized Rayleigh-Ritz method') as opposed to the classical version of the energy method; and (3) to ascertain the relative accura cy of the optimized Rayleigh-Ritz method by comparing eigenvalues dete rmined using this technique and those calculated using a very efficien t standard finite element code.