Research on the penetration characteristics of elliptical cross-section projectile into semi-infinite metal targets

Abstract

To better understand the penetration characteristics of the elliptical cross-section projectile (ECSP) into metal targets, a series penetration experiments of projectiles with different shape cross-section to semi-infinite aluminum target were carried out. The shape ratios of typical ECSPs were 1.25 and 1.56, respectively, and another was circular cross-section projectile (CCSP) which has the same cross-section area in accordance with ECSP. In the penetration experiments, the projectiles were launched with striking velocities ranged from 400 m/s to 1000 m/s, and strain sensors were arranged on the impact surface of the aluminum target to catch the dynamic response during the penetration process. Then, characteristics of cracks on the impact surface of targets, penetration depths and penetration trajectory were measured after the penetration experiments. The results indicated that the dynamic response and damage behavior of targets showed obvious asymmetry under the penetration of ECSPs. Strain data had a decreasing trend from the major axis to the minor axis of the ellipse, and the length and number of cracks of the ECSP were larger than that of the CCSP. Besides, a theoretical model was developed to explain the asymmetric deformation and failure behavior of targets based on the conformal mapping theory and the strain path method. Calculation results showed that the asymmetric deformation of targets was directly caused by the displacement boundary conditions of the ellipse.