Deformation And Stress Damage Of Base Bleed Propellant Under High Overload

The Base-Bleed Projectile use the gas produced by the base-bleed propellant to increase the pressure at the bottom of the projectile, so as to reduce the resistance and improve the range. Practices show that the base-bleed propellant endures high overload effect in the interior emission. And this effect causes the damage of part of the propellant, and affects the consistency of the combustion then lead to the range spread. Therefore, the researches of the deformation and stress damage of the base-bleed propellant have important engineering application value for further study of the mechanism of broken.First, based on the gun interior ballistic and the base-bleed interior ballistic theory, the coupling mathematical model of the combustion of base-bleed propellant and gun interior ballistic is established. Obtain the characteristic parameters of the base-bleed device and the interior ballistic. Analyze and calculate the overload of the propellant in the whole emission process.Secondly, this paper analyzes the material properties of the base-bleed propellant, establishes the mechanical model use the viscoelastic theory, and obtains the various forms of viscoelastic constitutive equation of the base-bleed propellant.Again, obtained the mechanical properties data of the propellant through the mechanics test; fitting the relaxation modulus curve using the PRONY series. And, take it as the mechanics performance parameters input of the numerical simulation for the propellant.Finally, simulate the action of deformation and the stress damage according to the load conditions on the propellant,based on the viscoelastic theory, by using the finite element analysis software ABAQUS,with the dimensional viscoelastic finite element method. Obtain the distribution of the stress and strain at any time in different conditions.