A Four‐Point Bend Technique to Determine Dynamic Fracture Toughness of Ceramics

Abstract

The procedure for determining quasi‐static fracture toughness of ceramics has been standardized. To expand the loading rate into the dynamic region, the dynamic equilibrium over the entire specimen needs to be satisfied to interpret the crack tip loading state with the far‐field loading conditions. Furthermore, to determine the loading‐rate effects, the loading rate at the crack tip should be nearly constant during an experiment. A new four‐point bending experimental technique, based on a split Hopkinson pressure bar, has been developed to determine the dynamic fracture toughness of ceramics at high rates under valid conditions, which is demonstrated through the determination of the dynamic fracture toughness as a function of loading rate for a silicon carbide (SiC–N).