Effect of Shock Induced Shear on Spall Strength of SiC-N

Spall strength of a hot-pressed silicon carbide marketed as SiC-N is determined to 16 GPa under both normal shock wave and under shock induced simultaneous compression-shear wave propagation. The preliminary results of this investigation suggest that shock induced shear under compression-shear wave propagation: (i) does bring about a decrease in the spall strength of SiC-N compared to under normal shock wave propagation and (ii) does seem to induce propagation of a failure front in SiC-N as evident from re-acceleration in the free surface velocity profiles in SiC-N prior to expected arrival of pull-back i.e., spall signal