Effects of Explosive Device with Foam Cushion and Air Clearance on Kinetic Characteristic of Steel Flyer under Detonation Loading

Based on a Doppler pin system, we studied the influence of a 0.5 mm-thick foam layer and an air clearance on the kinetic characteristic of a 45 steel flyer under the detonation of the RHT-901 explosive, and analyzed the difference in this influence as is shown between a single-flyer assembly and a double-flyer assembly according to the free surface velocity-time curves of the flyer of each.The experimental results show that the foam cushion and air clearance significantly affect the kinetic characteristics of the 45 steel flyer, including the take-off time of the flyer, the velocity jump amplitude and the final velocity.Comparing the effect of a foam cushion and that of an air clearance between the explosive and the metal flyer in the single-flyer assembly, we found that the take-off time of the metal flyer in the foam cushion region is later by about 30ns and the speed jump amplitude is higher by about 13% as compared to that in the air clearance area; comparing it in the double-flyer assembly, we found that the take-off time is advanced by about 200ns and the speed jump amplitude is reduced by about 6%.Nevertheless, the final velocities in the foam cushion region are lower than that in the air clearance area in the two experiments.Finally, we analyzed the influence pattern based on the stress wave propagation in continuum matter, and verified the rationality of the theoretical explanation by estimating the velocity of denotation products flying through air.