Holographic study of impact phenomena, part 2

Holographic studies of 10 mm thick ceramic disks struck by airgun pellets are compared with findings for 6 mm targets. Radial propagation of the deformation wave and axial deformation of the target are considered. The 10 mm targets have lower displacement velocities and greater fringe contrast, allowing deformation to be evaluated as a function of time. Radial propagation velocity relative to the moment of impact is 7200 m/sec for 6 mm targets, 5000 m/sec for 10 mm ones. Developing cracks follow the foot of the bulge at a constant distance, indicating that the crack tip propagates with the same average velocity as the foot of the bulge. Deviation between these results and previous ones are attributed to differences in the elastic properties of the ceramics.