Experimental investigation on ballistic stability of high-speed projectile in sand

Abstract

Abstract. The investigation on ballistic stability of high-speed projectile in granular materials is important to study the EPW (earth-penetrating weapon). Laboratory-scaled sand entry experiments for the trajectory in the sand have been performed at a range of velocities from 30 m/s to 150 m/s. In addition, pressure sensor was embedded in the sand to record the sand stress which reflects the penetration performance of projectile during the impact. The slender projectiles were designed into flat nose shape with three kinds of L/D (length-diameter ratio) to make comparisons on the trajectory when those projectiles were launched at normal and oblique impact angles (0~25deg) along a view window. A high-speed camera beside window was employed to capture the entire process of projectiles' penetration. Basing on the comparison of different tests, theoretical analysis is carried out on the relationship between ballistic stability and associated conditions. By utilizing DIC technique, the vector field of sand velocity was acquired, and the spreading direction of the impacting energy was observed. It can be concluded that the sand stress is the function of penetrating velocity, L/D and the shot angle. It increases with the growing of penetrating velocity and L/D, decreases with the shot angle. To a certain extent, the biggest initial velocity leads to the highest stress.

Analysis of the Behavior of a Penetrator Advancing Through a Guide Surface

“…The existing sabot uses two bore riders [6,7], a front part and a rear part, as shown in Fig. 1, so that the movement of the projectile is efficient with a high L/D ratio inside the bore [8]. The front bore rider of these two bore riders acts as an aerodynamic lifting surface to help the sabot disengage.…”

Numerical modelling study of a modified sandbag system for ballistic protection

“…Previously, studies have focused on the physical properties of sand and how they influence the penetration resistance of the system [2,4,6,13,17,22]. Observing the compaction behaviour and how it changes by modifying the sandbag creates the opportunity to improve the protection system performance with minimal changes to the filling.…”