Influence of projectile shape and incidence angle on the ballistic limit and failure mechanism of thick steel plates

The influence of projectile shape and angle of incidence has been studied on the ballistic limit, failure mechanism and angle of ricochet. The Weldox 460 E steel target of 12 mm thickness was subjected to impact by steel projectiles of 20 mm diameter and six different internal nose-angles, namely 33.4 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees and 180 degrees. The angle of incidence of the projectiles was also varied as 0 degrees, 15 degrees, 30 degrees, 45 degrees and 60 degrees or until the ricochet of the projectile occurred. The ballistic limit, angle of ricochet and failure mode of the target was studied corresponding to each angle of incidence and projectile shape. The residual velocities for each projectile were also computed using available analytical expressions and the same were compared with their numerical values. The results thus obtained are presented and influence thereon due to the variation in the nose-angle and obliquity of impact are discussed. The ballistic limit was found to increase with an increase in the angle of target obliquity and decrease in projectile nose angle. (C) 2013 Elsevier Ltd. All rights reserved.