Projectile oblique impact on granular media: penetration depth and dynamic process

• Published in: Granular matter Vol. 23; no. 2
• Main Authors: Ye, Xiaoyan, Wang, Dengming, Zhang, Xingyi, Zhang, Chaofeng, Du, Wei, Su, Xiyang, Li, Gang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2021; Springer Nature B.V
• Subjects: Acceleration; Complex Fluids and Microfluidics; Diameters; Drag; Engineering Fluid Dynamics; Engineering Thermodynamics; Foundations; Geoengineering; Granular materials; Granular media; Heat and Mass Transfer; Hydraulics; Impact velocity; Industrial Chemistry/Chemical Engineering; Materials Science; Model testing; Motional resistance; Original Paper; Penetration depth; Penetration resistance; Physics; Physics and Astronomy; Projectiles; Sand beds; Soft and Granular Matter; Terminal ballistics; Vertical penetration; Viscous drag; Oblique impact; Resistance force; Granular media; Penetration depth
• ISSN: 1434-5021; 1434-7636
• DOI: 10.1007/s10035-021-01108-3

The motion of a projectile oblique impacting sand bed with deep penetration was captured in experiment. Penetration depth, velocity and acceleration of the projectile were analyzed in terms of kinematic data. Horizontal and vertical penetration depths were measured under a series of impact angles, impact velocities and projectile diameters, and the collapsed curves were obtained. Specifically, an impact drag force model was assumed, which consists of an inertial term, a linear viscosity term, a linear static term, and a constant term. Then, we confirmed the terms related with velocities for both horizontal and vertical direction at the fixed depth-dependent term and obtained the linear depth-dependent static force at certain velocities. It demonstrated that viscous drag force is significant in deep penetration cases (vertical penetration depths are larger than the diameter of projectiles), but it can be neglected in shallow penetration cases. The generalized phenomenological resistance force model were proposed, which can predict the motion of projectile and resistance force exerted on the projectile by the granular medium at oblique impact cases. Graphic abstract