Numerical study of a spherical to plane wave diffuser for shock wave in solids

摘要

A shock wave is a pressure wave in the order of giga-pascal, and duration of nanoseconds, which propagates above thespeed of sound in a solid medium. The shock wave can be induced in a small area on the solid sample surface by a highpowerdensity laser pulse. As a result, the propagation of the shock wave, inside the solid, is considerate spherical.Waveguides can be used to drive a shock wave to a different point of interest. However, semi-spherical wave propagationinvolves some problems inside the waveguide, such as multiple reflections, phase shifts, and pressure decays due to wallreflections, among others. In this work, is proposed a finite element simulation of a spherical shock wave propagationinside a solid. We describe a method to correct a semi-spherical wave to plane wave propagation. We assume a pointsource semi-spherical distribution inside the material. The shock wave dispersion to the confining media is disregarded.The flat reflector location and shock trap geometry restrict the radius of curvature of the spherical reflector. This methodcan be useful to analyze the impulse response of solids to an incoming plane wave.