Abstract:

This Memorandum describes a computation procedure for the estimation of natural frequencies and mode shapes of isotropic and orthotropic rectangular plates under static in-plane loading. The static in-plane loading, uniformly distributed along the plate edges, may be any combination of direct and shear loading that does not cause the plate to buckle. The document provides details of the theory and method of computation used in the program listed in ESDU 90016. The development of the frequency equation is outlined, the orthogonal polynomial functions used in the displacement equation are defined, and the computations involving the orthogonal polynomials are considered. Notes are also provided on the computation procedures used in ESDU 90016 for the evaluation of the eigenvalues and eigenvectors.