Dynamic engraving characteristic analysis considering a parametric worn barrel model

ABSTRACT The wear of the barrel mainly occurred at the forcing cone, which greatly changed the projectile engraving characteristics and the gun’s inner ballistic characteristics. To further reveal the projectile-engraving dynamic characteristics of the large caliber wear gun, a parametric structural model of the worn barrel was proposed and regular meshed. A finite element model of the projectile dynamic engraving process was established under different barrel wear amounts, which considering the change of internal ballistic parameters caused by wear. The numerical calculation results were in good agreement with the experimental results and the projectile dynamic engraving characteristics under different barrel wear amounts were analyzed. The results indicated that with the wear intensified, the chamber pressure-boosting rates and projectile engraving resistance decreased, the projectile velocity and angular velocity at the end of the engraving process increased due to the projectile’s total engraving displacement increasing. As the barrel wear increased, the average stress on the belt element gradually decreased and the stress on the inner barrel liner reduced, the belt unit proportion sheared by the forcing cone was reduced. When the barrel wear was greater than 2.4 mm, the front belt showed a flattening phenomenon, which changed the groove shape and stress-strain state of the copper belt.