Numerical Simulation And Experimental Research On Dynamic Squeezing Of Bullets

Small-bore rifle projectile is taken as the research object in this paper.From the theoretical analysis,the force of the projectile during the engraving process and gunpowder gas energy dissipation was taken.Based on the finite element software,a high-precision finite element model was established coupled with the classic ballistic subroutine.The effects of different free-travel on the process of small-caliber projectiles were numerically analyzed.The dynamic and quasi-static engraving tests were designed to verify the correctness of the simulation results.The projectile engraving process is explained from three aspects:theoretical research,numerical simulation and experimental study,which provides some data references and theoretical support for modem bullet design theory The main contents of this paper are as follows:(1)The forces in projectile and the energy dissipation of gunpowder gas during internal ballistic process was analyzed.A fast calculation model of engraving resistance was deduced.Besides,based on classical internal-ballistic,a ballistic model for small-bore rifle projectile with engraving resistance existing was proposed to study the engraving process's impact on projectile movement.(2)A subprogram of internal-ballistic pressure VUAMP was designed in FORTRAN.Applying with ABAQUS and HYPERMESH,the high-precision finite element model for projectile engraving process was built and analyzed under display dynamic.Compared with the experimental data,the accuracy of the model was verified.(3)Against different free-travel length,the finite elements model of whole barrel was established,then the engraving process using internal-ballistic subprogram was simulated.The effect of free-travel on projectile's engraving process was acquired and the impact of different free-travel length on interal ballistic process was studied further.(4)The test scheme of quasi-static and dynamic engraving was designed,and the corresponding experiment platform was built.The experiment results for small-bore rifle projectile indicated that the numerical simulation is accurate.The intrinsic difference between the quasi-static and the dynamic engraving process was also analyzed.