Research On Initiation Response Of PBXs Under Quasi-Isentropic Loadings

The exploratory study on the initiation characteristics of PBX explosives under quasiisentropic loading is beneficial for understanding the growth processes of ignition and detonation of explosives under different loadings,and the reliability and safety of explosives under quasi-isentropic loading conditions.In this thesis,the combination of theoretical analysis,experimental research and numerical simulation is used to investigate the initiation response of PBX explosive under quasi-isentropic loading.A one-dimensional quasiisentropic loading initiation test system for explosives was established to determine the parameters of reaction rate model under quasi-isentropic loadings.The DYNA2 D program embedded in this model was used to carry out the numerical simulation study on the growth processes of ignition and detonation of PBX explosives under quasi-isentropic loadings.(1)Based on the double-layered hollow sphere elastic/viscoplastic pore collapse model(DZK model),the hot-spot formation and the ignition response of PBX-9404 explosive under quasi-isentropic loading were researched by numerical solution method.The influence rule of loading time,loading energy,loading impulses and binders on the ignition response of PBX explosives under quasi-isotonic loading was obtained.(2)Using the magnetic compression device CQ-4 and the multi-photon Doppler velocity measurement technique PDV,the experimental method and test system for detecting onedimensional detonation growth process under quasi-isentropic loadings were established.The initiation and detonation process of explosives under quasi-isentropic loading can be quantitatively described by the history curves of backside particle velocity at five different thicknesses in one experiment.The influence of different peak pressures on the initiation and detonation growth of PBX-C03 explosive under quasi-isentropic loading was obtained.The result shows that the one-dimensional quasi-isentropic loading initiation experiment presented in the thesis can replace the impact initiation experiment for the research on the growth of ignition and detonation of explosives.(3)Using the magnetic compression loading system,the mechanical response test of PBXC03 explosives under quasi-isentropic loadings was performed.The backside particle velocity of samples at three different thicknesses under two loading pressures was obtained.The p-v relationship of PBXC03 explosives and the parameters of Gruneisen state equation were determined by Lagrange method.(4)A one-dimensional model for calculating the detonation under the quasi-isentropic loading of explosives was established by the DYNA2 D program.By the backside particle velocity curves for the initiation and detonation growth process of PBXC03 explosives at different thicknesses under quasi-isentropic loading,the DZK reaction rate model parameters of PBXC03 explosives was determined,and the feasibility of replacing the impact initiation experiment with the initiation experiment under quasi-isotropic loadings to determine the parameters of the PBX explosive reaction rate equation is verified.The effect law of loading peak pressure,slope and curvature of quasi-isentropic loadings on the initiation response characteristics PBX explosive is obtained.