Transient sound fields from impacted plates: Comparison between numerical simulations and experiments

A comparison between measured and simulated transient acoustic fields gener ated by a thin rectangular impacted steel plate is reported. The plate vibr ation is modelled in the time domain using a finite difference scheme of se cond-order in time and fourth-order in space (2-4 scheme) and the radiated acoustic pressure is obtained by solving numerically the Rayleigh integral equation by using a simple Boundary Element Method (trapezoidal rule). The simulated results are evaluated in the form of the spatial pressure distrib ution at times short-after the impact excitation. The measurements are perf ormed using an optical method: pulsed two-reference-beam holographic interf erometry. Results in the form of 2-D projections of the acoustic pressure f ield are obtained and compared with the simulations. A high degree of simil arity is found between the measured and simulated sound fields. (C) 1999 Ac ademic Press.