THE VARIATION, WITH THE POISSON RATIO, OF LAMB MODES IN A FREE PLATE, .1. GENERAL SPECTRA

This study of Lamb modes in a free, elastic plate builds largerly upon the work of Mindlin, to which it makes various extensions and a few corrections. In addition to dealing with the more familiar region in which the Poisson ratio is positive, the increasingly important region in which it is negative also is investigated, and a set of Lamb mode spectra is presented covering the full range of the Poisson ratio. This set enables observations to be made of trends, both in the real and in the imaginary wavenumber domains. The work described in this paper has led to the identification of a number of problems which are investigated in two companion papers. © 1990.