Dynamic compressive strength of silicon carbide under uniaxial compression

SiC is used in impact related applications, such as integrated armor. This necessitates development of models which describe its dynamic behavior and failure modes. Experimental results, which relate the strain rate to the compressive strength of SiC under uniaxial loading are obtained. Quasi-static tests are performed using a hydraulically driven Instron universal testing machine. Dynamic tests are performed using a modified split Hopkinson pressure bar. A marked increase is observed in the compressive strength at strain rates greater than 102 s−1. The failure modes are similar in specimens loaded at both low and high strain rates. At the peak stress, the specimens fail by axial splitting. This paper compares the experimental results to those predicted by a simple model of interacting, dynamically growing, wing cracks which coalesce, leading to failure.