Study on the overdriven detonation wave propagation in double-layer shaped charge

In a double-layer shaped charge (DLSC), the shock initiation of the high-detonation-velocity explosive on the low-detonation-velocity explosive and the collision of detonation waves will produce overdriven detonation (ODD). In this study, the mathematical model for calculating the propagation path of detonation waves in a DLSC is established. The calculation formulas of ODD parameters near the contact surface of the two explosives are given. In addition, the collision of detonation waves is divided into three cases: normal incidence, normal oblique incidence, and irregular oblique incidence. The collision process of detonation waves is analyzed, and the calculating method of the critical incident angle of the Mach reflection is given. The Lee−Tarver equation of state is used to describe the process of ODD, and the propagation laws of Mach waves in a DLSC and in an ordinary shaped charge (OSC) are compared. The numerical simulation results coincide with the calculation results of the formulas, which verifies the accuracy of the mathematical model and the derived formulas of a DLSC established in this study.