Evaluation of breach behavior due to plate fragment impact

•Kinetic energy was used to compare contact charge detonation to plate fragment impact•Modified contact charge equations are proposed to evaluate plate fragment impact•Modified contact charge equations predicted thicker specimen response reasonably well•Calibrated numerical simulations analyzed plate fragment impact on reinforced concrete This paper presents modifications to existing relationships that analyze the breach potential of concrete elements subjected to impact by plate fragments. Experimental data associated with a previous study that evaluated plate fragment impacts were analyzed to determine the impactor kinetic energy required to cause reinforced concrete to present a breached condition. This value was compared to the energy that the existing contact charge relationships indicate is required to breach a wall of the same thickness. Modifications were made to existing contact charge equations to account for the difference between the contact charge energy required to cause a breach condition and that required from fragment impact to produce a breach condition. A numerical model that simulates concrete slab breach response was also created and utilized to further evaluate the breach relationships. These modified relationships provide the ability to determine the thickness of wall required to prevent a breach due to impact from a plate fragment at varying impact velocities; however, they appear to be less reliable for thinner slabs and are not recommended for low aspect ratio projectiles.