Experimental and Numerical Investigation of Projectile Penetration into Thin Concrete Targets at an Angle of Attack

This study presents a combined experimental and numerical investigation into the evolution of projectile attitude during oblique penetration into thin concrete targets at non-zero angles of attack. An oblique penetration test system was developed based on a cannon platform, incorporating a planar mirror reflection technique and high-speed imaging to capture the projectile’s spatial orientation. A set of equations was derived to relate the projectile’s three-dimensional attitude angles to its two-dimensional and mirror-reflected projections. The system demonstrated the ability to generate controlled initial angles of attack and accurately measure the projectile’s attitude, with measurement errors primarily within 2° and a maximum error of approximately 5°. Numerical simulations were conducted using the RHT strength model to replicate the experimental process. The simulation results showed good agreement with experimental data, with residual velocity errors less than 5% and attitude angle deviations below 15%. The validated model was further employed to study the effects of initial velocity, impact angle of attack, and target thickness on the evolution of projectile attitude. The findings reveal that, within a velocity range of 550–1000 m/s, the post-perforation attitude angle is negatively correlated with projectile velocity, though the variation remains under 15%. Increasing the target thickness from 90 mm to 240 mm significantly raises the post-perforation attitude angle and angle of attack by more than 70% and 20%, respectively. Under varying initial attitude angles, the final attitude angle increases with the initial value, with the maximum growth rate occurring around 15°, after which the rate gradually decreases. The angle of attack evolution during penetration can be divided into four stages: (1) crater formation, (2) plugging penetration, (3) breakthrough plugging, and (4) post-exit. These results offer valuable insights into projectile dynamics under complex impact conditions and provide theoretical support for the design of protective structures.