Impulse response methods to evaluate the reflection and transmission of acoustic pulses by viscoelastic plates

Abstract

An impulse response and convolution integral method is presented to evaluate the reflection and transmission of acoustic wideband planar pulses by fluid loaded multilayer viscoelastic plates. The reflected and transmitted pressure pulses are expressed as the convolution of the incident pressure pulse with the reflected and transmitted impulse response, respectively. The impulse responses are equivalent to the inverse Fourier transform of the reflection and transmission coefficients which are obtained by transfer matrix techniques for the multiplate configuration of interest. Extensive numerical results are presented to illustrate the main characteristics of the reflected and transmitted pulses which result from an incident pressure pulse impinging onto a plate. Both normal and oblique incidence are considered for single and multilayer plates. The results, which were obtained via the use of FFT methods, illustrates the pulse distortion as a function of plate configuration, plate losses, and angle of incidence.