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Title: Effect of surface roughness of charge hole on detonation propagation of emulsion explosive

Book ·
OSTI ID:398402
; ;  [1]; ; ;  [2]
  1. NOF Corp., Aichi (Japan). Explosive and Blasting Research Group
  2. National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan)

In the present study, some experimental work was performed to investigate the effects of surface roughness of the charge hole on the velocity of the precursor air shock wave. Photographic observation was performed using rectangular PMMA tubes with sandpaper on inner wall to simulate surface roughness for various decoupling coefficients. The experimental results indicate that the increase of surface roughness of the tube wall reduces the precursor air shock wave velocity and prevents detonation failure. It is shown that detonation failure occurs when the ratio of the precursor air shock wave velocity to detonation velocity becomes greater than 1.21 in the case of a rectangular PMMA tube. Precursor air shock wave velocity and detonation velocity were measured using PVC pipes of various inner diameters with sandpaper on the inner wall to simulate actual charge hole roughness. Sample explosive confined in polyethylene tubes of 20 mm in diameter was placed on the inner wall of the PVC pipe. The experimental results show that the increase of surface roughness of the PVC pipe decreases the velocity of the precursor air shock wave and improves the detonation propagation of explosive in the PVC pipe. It is shown that detonation failure occurs when the ratio of the precursor air shock wave velocity to detonation velocity exceeds 1.1 times in the case of the PVC pipe. The difference observed between the experiments with a rectangular PMMA tube and those with a circular PVC pipe is due to the difference of precompression mode of unreacted explosive by precursor air shock waves.

OSTI ID:
398402
Report Number(s):
CONF-960262-; TRN: IM9649%%610
Resource Relation:
Conference: 22. annual conference on explosives and blasting technique, Orlando, FL (United States), 4-8 Feb 1996; Other Information: PBD: 1996; Related Information: Is Part Of Proceedings of the twenty-second annual conference on explosives and blasting technique. Volume 1; PB: 319 p.
Country of Publication:
United States
Language:
English