TRANSVERSE VIBRATIONS OF RECTANGULAR-PLATES ON INHOMOGENEOUS FOUNDATIONS .2. MODAL CONSTRAINT METHOD

A method is described for establishing the lowest natural frequencies of simply supported and clamped plates on inhomogeneous elastic foundations. The method is based upon the modal constraint technique. The merits of this method lie in the fact that the eigenvalues and eigenfunctions of a simply supported plate and scalar springs are used to calculate the eigenvalues of the modified structures. These modifications consist of coupling these structures and/or adding rotational constraints. A number of configurations of inhomogeneous elastic foundations have been considered. Excellent agreement is shown to exist between the eigenvalues determined in the present paper and those calculated using the Rayleigh-Ritz method by Laura and Gutierrez in Part I of this joint project.