Material similarity law of blunt projectiles penetrating scaled steel target plates

Abstract

This study aims to enable the use of target plates composed of different materials in the penetration problem through the H-method similarity framework. Since different fracture toughness can lead to imperfect similarity between models, the concepts of Volume-failure strain and Volume-yield stress are introduced, which can well describe the high-velocity penetration problem involving fracture toughness. To ensure that the initial velocity of the projectile does not change, the similarity distortion among scaled models composed of different materials and the prototype is compensated by changing the target plate thickness. The feasibility of the proposed method is preliminarily proven based on the analysis model of the dimensionless critical impact energy of the target plate and the residual velocity of the projectile during penetration. Moreover, numerical simulations of blunt projectiles penetrating steel plates are performed. By changing the target plate thickness, the similarity differences among scaled models composed of different materials are effectively resolved. The errors of the residual velocity and peak force are in a completely reasonable range.