Based on the discrete element software PFC2D, building background grid model of concrete under simulated different projectile penetration rate, in the process of penetration of concrete target, the expansion of the crack damage, and compared with the cement mortar model. In crushing zone near the projectile formation, in away from the projectile as the big crack area, cement mortar in the move away from the projectile distribution is symmetrical, mainly along the coarse aggregate and cement mortar and concrete crack of interface to conduct; To monitor the energy conversion in the process of projectile penetration, further combining with the energy dissipation structure it was pointed out that the essence of the penetration process of damage is caused by the energy dissipation of driven by energy release of a state instability phenomenon, is a combination of energy release and energy dissipation is the internal cause of penetration gradual damage.
