Transient acoustic radiation from elastic plates
Abstract
An expression for the acoustic radiated pressure emanating from an infinite elastic plate excited by a unit impulse load for different observation angles and distances is obtained analytically. The solution is obtained by use of Fourier transform on time and Hankel transform on the radial coordinate. Using Cauchy contour integration theorem and regular and modified saddlepoint methods, the inverse Fourier and Hankel transforms were evaluated. The unit impulse response and convolution theorem was then utilized to obtain an expression for radiated pressure of an infinite elastic plate excited by constant magnitude load, square pulse and CWpulse loads. The first arrival of acoustic wave at an observer point in the acoustic medium due to an impulse load was shown to correspond to the time of travel for the normal distance from the observer to the plate. After the first arrival, the acoustic pressure was shown to decay sinusoidally with an increasing period of oscillation. The decay rate for long times was shown to be the reciprocal of elapsed time. Similar response was shown for a square pulse and for a CWpulse after the removal of the load.
 Publication:

Ph.D. Thesis
 Pub Date:
 April 1979
 Bibcode:
 1979PhDT........66S
 Keywords:

 Acoustic Propagation;
 Elastic Plates;
 Sound Waves;
 Acoustic Measurement;
 Cauchy Integral Formula;
 Continuous Radiation;
 Fourier Transformation;
 Hankel Functions;
 Saddle Points;
 Square Waves;
 Acoustics