Time-dependent inelastic deformation of shocked soda-lime glass

Plate impact experiments were carried out to understand inelastic deformation in soda-lime glass shocked between 3 and 10.8 GPa. In-material, wave profile measurements were obtained using longitudinal and lateral stress gauges (4.6-10.8 GPa), and electromagnetic particle velocity gauges (2.9-6 GPa) at comparable sample thicknesses. The 4.6 and 6 GPa experiments revealed time-dependent material inelastic response along with time-dependent loss of material strength. Because of the unsteady, two wave structure observed in the longitudinal wave profiles in conjunction with the time-dependent changes in the lateral stress data, previous interpretations of the shocked soda-lime glass response in terms of a propagating failure wave are not valid. At higher peak stresses (similar to10 GPa), the experimental results do not display time-dependent strength loss. The shock wave response of soda-lime glass over the 4-10 GPa range is complex, and material strength and inelastic deformation features depend significantly on the peak stress. Using the experimental results, a phenomenological continuum model incorporating the various material phenomena was developed. Wave profile simulations using the continuum model show reasonable overall agreement with the experimental profiles at different stress levels. Because of the approximate nature of the continuum model, all of the experimental details were not reproduced in the wave propagation simulations. It is likely that around and above 10 GPa, other material phenomena not included in our model may need to be considered. (C) 2004 American Institute of Physics.