Research On Dynamic Mechanical Properties Of Modified Double-base Propellant Under High Strain Rate

The development of a new generation of tactical weapons technology,such as gun launched missile technology,extended range projectile technology and terminal correction mortar technology,has put forward higher requirements on overload resistance of solid rocket motor.The solid rocket motor equipped in t hese new tactical weapons bears high overload,and high strain rate deformati on of the internal solid propellant charge under very high axial impact load o ccurs,which is an important cause of charge structure damage.To improve the structural strength of power charge under the impact load, it is necessary to carry out research on dynamic mechanical properties of solid propellant under impact load.SHPB(split hopkinson pressure bar)experiment is an effective experiment al method to study the mechanical behavior of materials at high strain rate.ai ming at a kind of modified double-base propellant, the traditional SHPB syste m is improved and high strain rate compression tests under normal temperatur e are carried out through the improved SHPB system, by which the stress-stra in curves of the material within the range of strain rate 400s-1-5000s-1 are obt ained.Furthermore,the stress uniformity of the SHPB experimental specimens is studied through the finite element simulation method.The simulation results s how that the internal stress uniformity of the experimental specimen satisfies t he requirements.The results of the SHPB experiment show that the compression mechanic al behavior of modified double-base propellant at high strain rate has a signifi cant correlation with strain rate.According to the experimental data,the relation ship between mechanical parameters describing the yield behavior of modified double-base propellant and strain rate is obtained.Finally according to the stress-strain curves obtained through the SHPB e xperiment,the parameters of ZWT constitutive model of high strain rate are ob tained using the method of least squares fitting and it is founded that this mo del can well describe the the mechanical behavior of modified double-base pr opellant before yielding and in the vicinity of yield point at high strain rate.