Experimental and theoretical investigations on the failure behaviors of projectile during high-speed impact into concrete slabs were performed in this study. The ogive-nose projectiles after impact experiments were recovered and their microstructures were observed by scanning electron microscope and metallographic microscope. Mass abrasion and nose blunting are the typical failure models of steel projectile. Furthermore, thermal melting and cutting are the two main failure mechanisms. Based on the microscopic experimental results, a theoretical model of ogive-nose projectile subjected to impact loading considering the melting and cutting mechanisms was proposed. A modified cap model is introduced for describing the failure behavior of concrete targets, and then the dynamic cavity expansion theory is used to determine the resistance of projectiles during penetration. Besides, combining with the two-dimensional heat conduction equation and abrasive wear theory, the two main abrasion mechanisms of melting and cutting are included in the proposed model, which breaks through the framework of previous abrasion models with single abrasion mechanism. The predicted results of the present abrasion model are in good agreement with the experimental data, which indicates that the proposed model can effectively predict the failure behavior and penetration performance parameters of high-speed projectiles during penetration into concrete targets, such as mass loss, nose blunting, and depth of penetration.
Keywords: concrete slabs; impact test; structural failure; theoretical model.