The effect of annular multi-point initiation on the formation and penetration of an explosively formed penetrator

Using LS-DYNA software, this paper studies the problem of an annular multi-point initiation circuit applied to an EFP charge, and the effects on the penetrator formation parameters, such as velocity and length-diameter ratio, by examining the number of initiation points, the initiation position, and the synchronized initiation deviation of the annular multi-point initiation circuit. It reaches the conclusion that when there are six or more initiation points, the formed EFP of a multi-point initiation project is similar to the result of a peripherally initiated charge. It also finds that the change of across velocity gradient is the main cause of bending distortion of the penetrator, and that the formed penetrator cannot bend if the multi-point synchronized initiation deviation is less than 200 ns. The simulation results were validated through X-ray imaging experimentation. Both results are in good agreement. It was found that, with the increase of the initiation annular radius, the EFP velocity improves by 24%, and the length-diameter ratio increases by more than 5 times.