Prompt Observation of Elastic Resonance Spectra Via the Use of Short Ultrasonic Pulses

It has been shown by L.R. Dragonette, S.K. Numrich and L.J. Frank [1,2] that the echo scattered by an elastic body can be considered as t he superposition of the elastic response of the target superimposed to the response o f a rigid body having the same shape. T his result has b eenused to analyse t he insonification of long cylindrical wires by short ultrasonic pulses. We show that the F ourier transform o f the elastic contribution alone g ives directly the resonance spectrum of the cylinder. This method has been checked on wires of different materials the v alues of ka involved were less than 50. The positions of the resonances in ka are in good agreement with theoretical predictions 131 as it will be verified by Regge's trajectories [41.