年間 6 号発行
ISSN 印刷: 2150-766X
ISSN オンライン: 2150-7678
Indexed in
PLATE DENT TESTS AND SEDIMENTATION OF PARTICLES IN MELT-CAST EXPLOSIVES
要約
A short experimental study demonstrated that the plate dent test is very sensitive to the last few centimeters of explosives at the bottom of the cylinders. The tests were performed by simply detonating an explosive cylinder with a small thickness (12.7−25.4 mm) of a different explosive (faster, slower, inert) at the bottom. The study will present how those small thicknesses influence the dent depth and hence the reported performance. Cylinders of explosives were cast and then cut to determine the extent of sedimentation of the HMX particles. Densities were taken at various places and concentrations of HMX were extrapolated from those. It was found that there was a difference of 22% in the percentage of HMX from the bottom and the top of the cylinder (66% vs. 44%; theoretical average was 52.8%). The explosive at the bottom was then significantly different and more powerful than the one at the top. The study will also demonstrate how the situation can be worse in real artillery shells. Given the results of the plate dent experiments reported before, it will be demonstrated how in theory one could be misled on the plate dent test by letting particles settle. Simple precautions can be taken to eliminate this variable and to ensure that the results of the plate dent test are meaningful. It also serves as a reminder that the composite explosives that we test, especially the melt-cast explosives, have large variations in their composition from sample to sample.