Fragmentation of brittle materials at high rates of loading

Experiments involving the fragmentation of SiC during both quasistatic and high-rate compressive loading are described. Measured fragment size distributions are considered in terms of current ideas regarding high strain rate damage and microfracture. The fragmentation of SiC at strain rates above 2000/s, and stress levels below the Hugoniot elastic limit, seems to be compatible with two concurrent dynamic damage mechanisms. The first is the development of microcracks at intrinsic microstructural flaws at a rate controlled by stress wave-flaw interaction kinetics. The second, more speculative, mechanism involves the possibility of microcrack nucleation at the heads of shock-induced dislocation planar arrays. 26 refs.