Dynamic engraving characteristics of nylon belt under different charge conditions

Abstract

Abstract In the present study, a 105 mm short tube gun system was designed to conduct the firing experiments under low charge conditions, which could precisely obtain the projectile displacement data and projectile base pressure data during the engraving process. Besides, a 3-dimensional dynamic engraving FEM-SPH model was established by coupling the internal ballistic process to much authentic investigate the engraving characteristics of the projectile, which were verified and compared through the experiment. On this premise, the influence mechanism and engraving features of the nylon belt were numerically calculated under higher charge conditions. The comparison between the experimental recovery belt and the numerical calculation results shows that the damage to the front of the nylon belt is axial compression wear, while the damage to the back of the nylon belt is circumferential shear wear. The direction of force exerted by the slope chamber and the projectile body on the belt was inconsistent, causing a bulge in the middle of the nylon belt. The more rapid the average boosting rate, the stronger the instantaneous impact on the nylon belt, the larger the stress and the strain damage on the nylon belt, the higher the pressure at the end of the engraving process and the greater the maximum engraving resistance. When the average boosting rate increased from 2.7 MPa⋅ms−1 to 33.0 MPa⋅ms−1, the engraving time was shortened by 73.9%, while the maximum engraving resistance increased by 78.2%.