Effects of three-point initiation control parameters on formation of explosively-formed projectiles with fins

Effects of the three-point initiation control parameters on the formation of an explosively-formed projectile (EFP) with fins were studied, including initiation diameter and initiation synchronization error. The Mach wave parameters (pressure and Mach wave domain area) at the metal liner were calculated theoretically at different initiation diameters. The fin formation and stable-flight velocity of EFP caused by the synchronization error at different initiation diameters were investigated by employing the LS-DYNA software. Results indicate that the Mach wave domain area decreases, but the pressure, final velocity and length-to-diameter ratio of the EFP increase, as the initiation diameter increases. It is noted that a better empennage formation can be approached when the initiation synchronization errors at the initiation diameters of 30, 40, 50 mm are less than 50, 100, 150 ns, respectively. In addition, the lateral velocity of the EFP is lower and the flight stability is higher when the delay time of the middle detonation point is about half the maximum delay time of the three initiation points.