Propagation of Failure Front in Shock-loaded Polycrystalline Alumina

The dynamic failure behaviors of brittle alumina under shock compression were investigated in this paper. Plate impact experiments were carried out on alumina whereas the free surface velocity profiles were measured through VISAR and the recovered samples were scanned with SEM. The failure front manifested to propagate in the material when the particle velocity history at free surface was checked. The dynamic failure mechanism in ceramics was generally probed associated with the consideration to the mesoscopic structural characteristics as well as induced stress distribution singularity within the mesoscope. Dynamic failure properties of the failure front were discussed occurring in the alumina. A dynamic failure model of shock-loaded alumina and the governing equation of failure front propagation along with a respective failure criterion were built up. A numerical results on propagation of failure front in terms of longitudinal and transverse stress in alumina were presented.Key words: alumina, plate impact experiment, failure front, failure model