Quasi-static and dynamic engraving of small calibre projectile

The engraving process of projectile is one of the main topics of interior ballistics and has not been well known till now. Our study focuses on engraving small calibre projectile under quasi-static and dynamic loading conditions. Quasi-static tests were carried out on a MTS 810 and a gas gun-based test rig was specially designed to perform the dynamic tests. The hoop and axial strains of the outside surface of the gun barrel were monitored and analysed to reflect the interaction between the projectile and the barrel. The effects of projectile structure and loading rate on the engraving process were investigated. The experimental results showed that severe friction between the projectile and gun bore occurs and plastic deformation of the copper layer increases the engraving resistance. Changes in force and strain under different conditions indicate that many factors including projectile structure and loading rate have great influences on the engraving process. [Received 20 July 2016; Accepted 16 November 2016]