Dynamic Compressive Response of Intact and Damaged AD995 Alumina

The dynamic compressive responses of AD995 alumina have been determined as a function of loading rates and damage levels. To determine the dynamic properties under loading conditions simulating those encountered in ceramic armors subjected to impact, a novel dynamic compressive experimental technique modified from a split Hopkinson pressure bar (SHPB) was employed to load the ceramic specimen by two consecutive stress pulses. The first pulse determines the dynamic response of the intact ceramic material and then crushes the specimen. Before the specimen disintegrates, the second pulse determines the dynamic compressive constitutive behavior of the ceramic rubble that is still interlocked. The results show that the compressive strengths of damaged ceramics are insensitive to strain rates once the damage level exceeds a critical value.