Dynamic Compression of RDX Single Crystal and High Explosives

Dynamic compression and failure of energetic RDX single crystals and high explosive PBX 9501 are studied experimentally using a miniature Split Hopkinson Pressure Bar (SHPB) combined with high-speed photography and optical digital image correlation (DIC) technique. In addition to the strain gages mounted at the center of the incident and transmitted bars, high-speed camera, running at the rate of 5 million frames per second, was used to capture the deformation process of the RDX single crystal and the PBX 9501. A random speckle pattern was also printed on the sample surface and optical DIC technique was applied to map out the displacement and the strain fields over the sample surface, as well as to capture the crack initiation and extension process. A technique was developed for quantitatively identifying crack, the motion of the crack tip, and extracting the fracture toughness of a brittle material in compression. Combined with the dynamic compression setup, we will be able to study the deformation and failure processes in much detailed and quantitative fashion.