Abstract: With the aid of the VISAR, the velocity histories of rear free surface of the alumina with different thicknesses under plate impact loading were recorded. The failure wave trajectory was obtained from the recompression signals observed in the temporal curves of rear free surface velocity of samples. The results indicate that the generation and propagation mechanisms of failure wave are closely related to the mesoscale failure properties of alumina. The mesostructure properties of tested alumina were studied according to the SEM of alumina samples. Based on these properties, a mesoscopic model of alumina, including alumina grain phase and glassy phase, is established. Further, mesoscale simulations were presented to analyze the mesoscale failure properties of alumina. And the generation and propagation mechanisms of failure waves in shocked alumina were researched at the mesoscale. The results show that the nucleation and growth of rapid in-situ grain boundary microcracks under impact loading give rise to the failure wave phenomenon, and the failure wave propagation may be governed by diffusion processes. Key

Key words: solidmechanics, shockcompression, alumina, mesoscalefailure, failurewave