Patent ID: 8392133

Claim:
A method to measure a shear wavespeed of waves in an isotropic plate, comprising the steps of: providing the isotropic plate in a manner to minimize dynamic mounting forces; applying a time cyclical point force having a known frequency and magnitude to the plate to initiate waves in the plate; measuring normal velocity of the waves as a temporal domain measurement in a spatial domain on a first planar surface of the plate; transforming the temporal domain measurement into a frequency domain; transforming the frequency domain measurements into a {kx, ky} wavevector domain spectra using two Fourier transforms, one transform for each dimension, kx and ky; determining propagation wavenumbers for given Lamb waves from peaks within the {kx, ky} wavevector domain spectra; and determining a shear wavespeed of the waves in the plate by using the determined propagation wavenumbers, wherein propagation wavenumbers are determined by applying a Newton-Raphson gradient method to Raleigh-Lamb dispersion curve equations.