NUMERICAL RESEARCH ON THE IN-BORE PROCESS OF RIFLE BULLET

摘要

In order to analysis the dynamic response of bullet and barrel during the in-bore process, bullet base pressure was calculated by interior ballistic theory, and numerical model of bullet in-bore process was established, the numerical model was validated by experimental results, which include muzzle velocity, spin velocity, width and depth of engraved bullet vestige, the maximum difference between the numerical and experimental results is 5.88%. The engraving process and engraved vestige on bullet, the changing of stress in bullet and barrel, and also the changing of temperature in bullet jacket were calculated, the study indicated that in engraving process, the maximum plastic strain in bullet engraved vestige is at right, and the maximum von-mise stress in rifling is at left, the left of rifling produced major contribution of the spin motion. The internal energy of jacket increased due to plastic deformation and friction at engraving process, which is 79.8% versus all internal energy increased, the other process is 20.2% and originates in friction mainly. After in-bore process, at bullet engraved vestige, the maximum temperature changing is reach to 235K, and the changing at other region is about 40K.