Study of Elastic Barrel Deformations and Vibrations Impact on Shooting Accuracy

Abstract

The paper presents the formulation of the problems of vibrations during a shot. A distinctive feature is the account of projectile interaction forces with the bore of a variable section barrel while taking into account the barrel's initial bending, which is found from solving the problem of gravitational deflection. To determine projectile motion forces, the problem of internal ballistics is solved in averaged parameters in the thermodynamic approximation. An implicit second order of the accuracy scheme in time and space was applied to solve barrel vibrations' problems. Comparing the solutions obtained in the ANSYS finite element analysis system in a three-dimensional formulation with the solution of the problem in a one-dimensional formulation is carried out. Calculation of the projectile external ballistic trajectory was carried out by solving a system of differential equations with the initial conditions determined from the internal ballistics problem's solutions and the barrel transverse vibrations in the vertical plane. The influence of barrel vibrations on the angle of departure was studied, the range of the projectile flight was determined for different firing conditions. It is shown that the deviations caused by deformation and vibrations of the barrel during firing from the gun considered in this work lead to a decrease in the firing range at small elevation angles and an increase in the range at large elevation angles. The results obtained make it possible to determine corrections of departure angle arising from the barrel vibrations on firing.