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Digital Speckle Radiography (DSR), a technique allowing measurement of the full field displacement maps in a plane within an opaque material, is used to follow the temporal progression of a long-rod (100 mm long, 10 mm diameter) penetrating a granular sample at a variety of rates. Quasi-static rates of 1.5 mm/min are achieved using an Instron machine, 5 m/s is achieved using a drop-weight and velocities between 10 and 200 m/s are achieved using a light gas gun. These experiments are carried out using a series of time delayed flash x-ray images analysed with an optimised Digital Image Cross Correlation algorithm (DICC). The subsequent data sheds considerable light on the response of granular materials to penetration at a variety of rates. Particularly, a large difference in the response of the material between quasi-static and dynamic rates is observed. [ABSTRACT FROM AUTHOR]

Experiments were carried out, at a strain rate of 1600 s-1, to characterise an HTPB/sugar propellant simulant within the temperature range of 50 °C to -100 °C. Optical techniques, namely high-speed photography with digital speckle analysis for flow visualisation, and line-laser occlusion to measure diametric expansion, were deployed. Agreement was found with the results of a previous study on a similar material: failure occurs by dewetting at temperatures above the glass transition temperature and brittle fracture occurs below. The peak strength of the material was recorded to be 80 MPa, measured at a temperature of -80 °C. [ABSTRACT FROM AUTHOR]