DERIVATION OF THE CONSTITUTIVE MODEL OF HIGH ELASTIC LIMIT WINDOW MATERIALS

Transparent materials with a high Hugoniot Elastic Limit are often used as optical windows in shock experiments. Parameterised models for both compressibility and elastic distortion are needed, especially to allow future experiments to be optimised using computer simulation. Heterodyne velocimetry has been used to generate shock velocity versus particle velocity data for sapphire shocked within its elastic regime. The data is consistent with other workers findings. The elastic distortion of the sapphire has been modelled by assuming that Poissons Ratio remains constant and compressibility has been modelled by using a Mie-Gruneisen equation of state. Velocity profiles computed using the constitutive model have been comparted with experimentally determined profiles.