Prediction of natural frequencies of rectangular plates with rectangular cutouts

Abstract

A simple numerical method based on the Rayleigh quotient is presented for predicting the natural frequencies of the fundamental and some higher modes of a rectangular plate with an arbitrarily located rectangular cutout. The edges of the cutout are parallel to the edges of the complete plate. The nodal patterns of these higher modes are pre-selected based on the symmetry of the mode shapes about the geometrical axes. The method is applied to the study of linear vibration of rectangular plates simply supported along one pair of opposite edges with any other boundary conditions at the remaining edges. The predicted results compare favourably with the corresponding results produced by other methods whenever available. © 1990.