The Ballistic of Fragment Penetration into Clay Soil

Abstract

Trajectory of projectile penetrating the soil had many research. But because of the complexity and diversity of soil, the projectile will tumble and form a cavity. This will cause the instability of trajectory and other issues, which make it difficult to quantitatively analyze the mechanical properties of soil. In this paper, the theoretical calculation and analysis have been performed using the trajectory which is formed by the high-speed fragments penetrating clay. The results indicated that there is a critical velocity, which is close to the sound velocity of soil in this place. The ballistic is divided into two parts-the funnel pit and the normal perforation. These show that the penetration is divided into the high-speed section and low-speed section. And there are two different drag coefficients. Cavity effect exists in the high speed penetration section, and the cavity resistance has a nonlinear relationship with the size of cavity.