Deformation and perforation of thin metal plate under normal penetration of elliptical cross-section projectiles

In this study, the penetration experiments on thin metal plates with four elliptical cross-section projectiles (ECSPs) were carried out to explore the deformation and perforation of target under the normal penetration. The projectiles were launched by the 40 mm air gun with impact velocities ranged from 200 to 350 m/s and the residual velocities of projectiles were experimentally obtained. The experimental results showed that the shape ratio of the ECSP had a great influence on the deformation characteristics of the target. In addition, Strain sensors were arranged on the impact surface of the metal plate to capture the dynamic deformation during penetration. The correlation between the peak value of the strain signal and its variation with the azimuth angle, the mean square deviation of the peak value, etc. were analysed in detail. Besides, the correlation numerical simulation was conducted to better understand the response characteristics of target and the accuracy of the numerical simulation method was verified by the above experimental results. The similarities and differences of deformation and damage characteristics of targets under different projectiles were analyzed by comparing the radial displacement and radial/tangential stress of targets. The results showed that for ECSPs, the stress in each direction was closely related to shape ratio and circumferential angle. The target was subjected to the coupling of compression and shear stress, which was greatly different from the result of circular cross section projectile.