Modeling and simulation of bullet-barrel interaction process for the damaged gun barrel

Abstract

In this paper, the influences of bore damage on the bullet-barrel interaction process and the mechanism of how bore damage results in the end of a machine gun barrel's service life were studied, which had seldom been paid attention to in the past several decades. A novel finite element mesh generation method for the damaged barrel and a new transient coupled thermo-mechanical finite element (FE) model, which were based on the damage data obtained through barrel life tests, were developed to simulate the interior ballistics process of a coupled bullet-barrel system. Additionally, user subroutine VUAMP was developed in the FE model in order to take the bullet base pressure brought by propellant gas into account. Good consistency between the simulation results and the experimental results verified the preciseness of the proposed mesh generation method and the FE model. The simulation results show that the increase of bullet's initial disturbance at the muzzle and the variation of its surface morphology caused by bore damage are primarily responsible for the life end of this 12.7 mm machine gun barrel.