Digital Speckle Radiography in the Penetration of Granular Materials

摘要

The experiments proposed in this research project will use a combination of impact testing and advanced image analysis. Targets will be made of MK4 Grout, in order to reproduce the response of geological materials. These will be impacted by projectiles which examine a number of nose geometries e.g. hemi-spherical, conic, ogive. The use of flash X-rays in this system, to capture images during the impact, means that the samples will have to be of a diameter which is small enough to allow good resolution but sufficiently large to avoid edge effects. The targets will be supported by Kevlar, or similar, fabric in order to maintain target integrity until late in the impact process. This will allow the deformation fields around a projectile tip and also in the bulk of the material to be examined. The analysis element is based on Speckle Cross Correlation and is described in some detail below.