Estimation of the shock to detonation region inside an energetic material

A series of six tests were conducted investigating the shock-to-detonation transition (SDT) in cylindrical samples of HE with a wax binder. A 40 mm powder gun was used to launch spherical steel fragments at a mean velocity of 1519 m/s into the HE. For each test 9 piezoelectric pins were placed just below the surface of the HE and situated to form a plane that bisects the HE sample. The pins were positioned such that 8 were along the side of the cylinder with the 9th pin opposite the impact location of the cylinder. The 9 pins were used to record the detonation wave time of arrival (TOA). Using the piezoelectric pin TOA a basic kinematic equation can be written for the velocity between the start of the detonation wave and the TOA at the pin. A system of 4 equations is used to solve for the location in the plane, the velocity, and time when the detonation wave initiated. This approach was used for each unique combination of piezoelectric pins to estimate a region where the SDT transition occurred.