| By virtue of its excellent kinetic energy penetration and chemical implosion combined damage ability,the reactive liner can release a large amount of chemical energy during the process of penetrating the target,which can greatly improve the damage power of the ammunition warhead.Since the detonation wave generated by the explosive is sufficient to cause a chemical reaction of the reactive materials,it may cause a certain energy loss during the reactive jet formation,which seriously affects the damage power of the reactive shaped charge warhead.In this paper,the formation of PTFE/Al reactive jet under explosion load is studied by means of theoretical analysis,numerical simulation and experiment.The main research work and achievements are as follows:(1)A two-dimensional mesoscopic model of reactive materials with different proportions and different particle sizes was established by particle random distribution method,and the mesoscopic impact response of reactive materials was simulated.The results show that the temperature of the matrix at the interface between the particles and the matrix is the highest.When the matrix is broken,the temperature of the fracture surface is higher than that of the unbroken part.Therefore,the impact ignition of the reactive material first occurs at the interface between the particle and the matrix,and then continues to react along the crack.Increasing the content of aluminum or adding tungsten is beneficial to improve the impact temperature rise of the reactive materials,while the particle size has little effect on the impact temperature rise.(2)The quasi-static compression experiment and Hopkinson pressure bar experiment were carried out on the reactive materials,and the J-C constitutive model parameters of the reactive materials were determined according to the experimental results.Based on the gas-solid reaction theory,the chemical reaction rate of PTFE/Al reactive materials was calculated.The results show that the complete reaction of 100μm aluminum particles requires 6.9ms and 5μm aluminum particles requires 17.383μs at 1000 K temperature.(3)The forming behavior of PTFE/Al reactive jet was numerically simulated by using the integrated material model of reactive materials impact-induced deflagration.The results show that during the PTFE/Al reactive jet formation,the reactive materials occurred chemical reaction inside the jet.And due to the secondary collision of the inner layer of the liner,the reaction occurs from the inside to the outside.The chemical reaction in the reactive jet formation can be divided into two parts: local reaction stage and overall reaction stage.The reaction in the local reaction stage is relatively mild,and the reactive materials undergoes a violent deflagration reaction in the overall reaction stage.Secondly,the influence of changing the charge length on the reactive jet is not obvious;with the increase of the cone angle of the liner,the jet head is more condensed and the velocity decreases obviously.When the cone angle of the liner increases to 75 °,the reactivity of the reactive jet decreases obviously.With the increase of the thickness of the liner,the reactivity of the reactive jet gradually decreases,but the velocity of the jet head is not much different.(4)The jet forming experiments of two kinds of PTFE/Al liners(aluminum particle sizes are 5μm and 100μm,respectively)were carried out.The results show that the chemical reaction does occur during the reactive jet formation.The error between simulation and experimental results is within 8.0 %,which indicates that the simulation method used in this paper is feasible.Because the reaction rate of 100μm particle size is relatively slow,the jet morphology is relatively more condensed,and the energy loss during the jet formation process is less. |
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