Research On The Numerical Simulation Of Shock Initiation HNS-Ⅳ By Flyer

Shocking and initiating by a flyer is an important research direction of the in-line explosive train.In this paper,Lee-Tarver ignition and growth model was used to study the influence law of flyer shocking and detonating explosive from the flyer parameters and the charging parameters with the detonation threshold and output performance as evaluation indicator.First of all,the calculation model is built by using AUTODYN software.Then,the threshold velocity of flyer shocking and detonating explosive was calculated.The results shown that the numerical simulation results were in good agreement with reported results,verifying the correctness of the established model.The Lee-Tarver ignition and growth model was adopted to simulate the process that the flyers shock and detonate HNS-Ⅳ explosive with different materials,thickness,diameter and posture.The influence of different flyer parameters on detonation threshold was compared.The results shown that polyimide was better than other materials in terms of lower-energy of shock and ignition devices.Flyer parameter research shown that within a thickness range of 25～145μm,the threshold velocity of impact detonation decreased as the flyer thickness increased,the threshold velocity had no obvious change when the flyer thickness exceeded 145μm.Within a diameter range of 1.02～1.57mm,the threshold velocity gradually decreased as he flyer diameter increased,the threshold velocity tends to be a constant value when the the flyer diameter exceeds 1.57mm.The flyer’s posture has a significant impact on the threshold velocity of impact detonation,the threshold velocity also increased accordingly as the flyer angle increased within a range of 0～20°.According to flyer threshold velocity,the parameters of P~n·τand the James Criteria for HNS-Ⅳ explosive were obtained.Detonation threshold and output performance were used as the evaluation indicator to analyze the influence of charge parameters on flyer shocking and detonating explosive.The results shown that the threshold velocity of the flyer decreases with a charge diameter increased from of 1.5～2.0mm,and the threshold velocity tends to be a constant value when the charge diameter exceeds 2.0mm.The charge type also have significant influence on flyer shocking and detonating explosive.The flying velocity of HNS-Ⅳ explosives is the lowest,followed by the PBX9502 and PETN leads to maximum velocity.For HNS-Ⅳ,the explosive with density of 1.60g/cm~3and 1.55g/cm~3pressure increased as the charge density increasing,but the explosives become more insensitive and more difficult to be detonated.