Analysis of elastic wave signals from an extended source in a plate

Abstract

This paper considers the forward and inverse problems of an extended, finite source of elastic waves in a thick plate. The signals received at a point in the nearfield of a source are computed by a superposition of the signals found with a generalized ray algorithm from point sources of variable strength arranged along a straight line. Synthetic waveforms corresponding to several source types and spatial distributions on the surface and in the interior of the plate are shown. A processing algorithm is also developed which utilizes the signals detected at just one receiver point to obtain the solution to the inverse source problem. Examples are shown in which the time dependence and the spatial distribution of a source are recovered from synthetic waveforms.