Study On The Impact Safety Of HMX-based Thermobaric Explosives

In modern warfare,due to the increasingly strong defensive capabilities of military targets,the military's requirements for the anti-overload capacity of the internal charge of the missile during the penetration process are also increasing.The safety of explosives under high speed impact is one of the most important indexes to evaluate its anti-overloading performance.In this paper,the impact safety test of pellets was carried out from the perspective of formulation design.And the effects of binder content,binder type,and insensitive elementary explosives on impact safety performance of thermobaric explosives(TBE)were studied.Meanwhile,AUTODYN was used to simulate the impact process.The main research contents and results were as follows:First of all,the formulations of TBE were designed.Based on the theoretical analysis,the composition of the thermobaric explosive formulation was selected.Six different formulations were designed according to three influence factors.And their thermal stability and friction sensitivity were tested.The results showed that with the increase of binder content,the thermal stability of TBE was enhanced and the friction sensitivity of TBE was reduced,but excessive binder content would reduce the thermal stability of TBE.What's more,fluororubber could effectively improve the thermal stability of TBE.Polyurethane could efficiently reduce the friction sensitivity of TBE.And not only could TATB improve the thermal stability of TBE,but have a good desensitization effect.Secondly,the impact safety test of the designed formulation was carried out to determine the critical ignition velocity of the thermobaric explosive under high-speed impact,and the combustion pressure P_max of the recovered powder after impact was analyzed.The results showed that with the increase of binder content,the critical ignition velocity of TBE and P_maxwere increased.Compared with TBE of fluororubber system,the TBE of polyurethane system had better safety performance with the higher critical ignition velocity and smaller P_max.Besides,compared with HMX/NTO system,HMX/TATB system had higher critical ignition velocity and smaller P_max,so it was safer.Finally,the impact process of TBE was simulated.The simulation results showed that when the impact velocity was lower than the critical ignition velocity,there would be no ignition reaction;when the impact velocity was higher than the critical ignition velocity,there would be generate"hot spot"in the front end of the grain,where ignition reaction would occur;with the increase of impact velocity,the ignition time would be earlier.