Shell Explosive Reaction Intensity, Low Amplitude Shock Conditions

In the research on the safety of the nuclear weapon primary, in order to study whether HE can produce chemical reaction, quantitatively to assess the reaction violence in the accident, this paper is focused on the reactive characteristics of two kinds of HE (both HMX-based, JOB9003 and GO-924) under accident stress level much lower than those in SDT case, in the Susan test and the gap test with confinement.The research of this paper includes:· High-speed photography and flash X-ray radiography are both used to capture the process of Al shell's great deformation under low pressure. Front illuminations are used to get the development of the fracture on the Al shell. The relative energy release is analyzed from overpressure curves measured with some sensors.· By comparing the experimental data with the modeling results, it was found that the HE in the projectile produces reaction after considerably long time. And the expansion velocity of the shell is about one hundred meters per second, far below the velocity driven by detonation (about 2000m/s).· The post-test recovered fragments prove that the reaction violence remains on low level. The scar on the surface of steel part of the projectile shows that different reaction violence have happened, though the impact velocities of projectile are almost the same in these tests.· HE can produce different types of reaction in the gap test, in which HE is impacted by shock (about 2GPa) and undergoes smaller deformation relative to Susan test, including no reaction, mild reaction, reaction termination, deflagration, detonation. The mechanism of the ignition and reaction development of HE is discussed under these conditions.· By using of LS-DYNA program, the dynamic deformation processes of modeled the two kinds of experiments without HE reaction are calculated and show little difference from the experimental data when Plastic_kinematic model was used for lacking materials properties of other models. And preliminary modeling analyzes reaction process using ignition-growth model. But the results are not satisfied due to the complexity of real ignition mechanisms.The ultimate aim of the study in this paper is better understanding of the mechanism of ignition and development of chemical reaction of the concerned explosives, more quantitative measurement of reaction violence parameters, and more reasonable assessment of safety characteristics given according to the phenomena. Although the presented discussions and analyses are qualitative to needed extent, the conclusions and analyses provide lots of useful information, in comparison with the understanding level in past time,. Based on the presented preliminary experimental study, lots of experiments are needed to be carried out, including measuring the pressure growth in HE, and the velocity history of the flyer close to the HE.