Search

The performance of 7.62×54r BS32 armour-piercing incendiary (API) projectiles against ceramic-faced armour is investigated in trials for yawed impacts. Controlled yaw of the projectile was induced by chamfering the rear of the projectile, producing strong asymmetric lift forces on the tail of the round during the intermediate ballistics phase. High-speed video recorded yaw in two orthogonal planes immediately before impact. Projectile yaw varied in a sinusoidal manner at approximately 3.5m wavelength with a maximum of 8-14° at approximately 10m from the muzzle. Logistic regression was used to determine the penetration probability curve and V50 ballistic limit velocity which was found to be 735 ms-1 for the un-yawed projectiles but only 685 ms-1 for the yawed projectiles. [ABSTRACT FROM AUTHOR]

This paper follows a historical background on requirements‐based strategic armor research, leading to the materials in extreme dynamic environments program presented in Part I, now focusing on the developed technical aspects and state‐of‐the‐art. It starts with some background on dynamic testing techniques and a structural ceramics review. Then, selected armor ceramics research results and relevant single‐grain anisotropic crystal physics, microstructure, and defect mechanics mechanisms: Including pivotal armor ceramics research results prior to the adoption of the strategic research objective (SRO). Next, multiscale characteristics, crystal physics, planar features, anisotropy, and relevant mechanisms will be described. The historic progression/evolution of multiscale lightweight armor ceramics research results will be summarized, including multiscale dynamic deformation and damage characteristics. The focus of the following sections will be on the role of defects, quasi‐plasticity, and anisotropic crystal physics properties, including preexisting single grain synthesis and process‐induced planar features (aka twins) and planar deformation features (PDF); for example, nano‐amorphization in boron carbide. A new model for boron carbide processing planar features will be discussed. A schematic diagram illustrating the hypothetical formation of PDFs in a dynamic event is also presented. An expended canonical equation is introduced, suggesting possible strategies for boron carbide research using the canonical figures of merit approach. Finally, we highlight the efficacy of the materials by design process and approach in a multiscale framework for the simultaneous experimental and theoretical research trajectories guided by the accepted canonical equation. [ABSTRACT FROM AUTHOR]