EXPERIMENTAL AND NUMERICAL STUDY OF LASER-INDUCED SPALLATION IN GLASS

The study of dynamic failure under shock loading in very brittle materials such as glass is usually limited by the severe destruction of the tested specimens. In this article, an original approach toward studying this phenomenon, based on the post-shock examination of damaged targets, is presented. A high-power pulsed laser has been used to generate very short compressive pulses in glass targets, and this loading has produced limited damage in the samples. Spallation has been shown to result in the formation of a fractured layer near the rear free surface of the targets, and the influences of the main experimental parameters upon the finite thickness of this layer have been determined. The data obtained have been used to work out a simple macroscopic description of brittle spallation in glass, then this description has been coupled to a constitutive model implemented in a one-dimensional simulation code. The resulting model is able to predict the extent of the damage induced in a soda-lime glass target by a laser-driven shock. © 1995 American Institute of Physics.