The effect of structure on failure front velocities in glass rods

Symmetric Taylor and reverse ballistics tests were used in conjunction with high-speed photography to examine the characteristics of failure in fused silica rods. Experiments were performed at impact velocities up to 800 m s-1 yielding impact pressures to approximately 7 GPa. Failure front velocities were strongly dependent on impact pressure consistent with results for borosilicate and soda-lime glasses. One-dimensional strain waves were observed in some experiments before a one-dimensional stress regime was reached. For high impact pressures (> 2 GPa) the failure fronts followed almost immediately behind the incident shocks at a velocity near (√2) cS for fused silica, borosilicate and soda-lime glasses