Time-resolved photoelasticity imaging of transient stress fields in solids induced by intense laser pulses

Abstract

In this study, the spatial distribution of laser induced transient stress wave have been observed successfully by both shadowgraph and photoelasticity images using transparent materials. It has been found that photoelasticity images of polymer materials, such as epoxy resin, observed in laser irradiation under water provide clear images which would allow quantitative estimation of the magnitude of laser induced stress. Obtained photoelastic images show clear black-and-white patterns from which laser-induced stress distribution and its dynamical change can be deduced. When a metal film was coated on the surface of an epoxy block, obtained images from the sample indicate the interaction of laser with the metal surface. A semi-quantitative estimation of intensity of the laser-surface interaction has been carried out by comparing images to those obtained for designated pulse energies. © 2007 IOP Publishing Ltd.