Vol. 9 No 5 October 2001
Ballistic Evaluation Technique
augmented with Fibre Optics Cable for Detonics & Shock Dynamics
Measurement of Detonation Velocity
In velocity measurement mode, a number of optical pins are fixed at the outer surface of a cylindrical explosive to record the arrival of detonation wave at the pin locations. The other ends of the optical fibre cables are arranged in a straight array for viewing by a high-speed rotating mirror streak camera Distances of the optical pins from the explosive initiating are marked on the camera record
Measurement of Shock Velocity
Remote pin arrangement was made in which the fibre collects the light from a distance and the optical pin does not disturb the motion of the shocked surface. In remote pin arrangement, a number of flat-bottomed cylindrical holes are drilled at different depths in a test specimen. Fibre cables are fixed on the specimen's free surface to directly view the shock breakout at the bottom of holes The distances of the bottom of cylindrical hole from explosive metal interference are marked in the camera record. The depth of the hole determines the time for which the shock luminescence remains visible to the fibre cab.