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To increase largely the performance of shaped charge, it is required to generate detonation velocity much higher than CJ velocity or detonation pressure much higher than CJ pressure of existing high explosives. One solution is the application of overdriven detonation phenomena. In this study, the effects of overdriven detonation in tungsten loaded high density explosive on the performance of shaped charge were demonstrated by experiments and numerical simulation. Sample shaped charge was composed of the inner layer tungsten loaded high density PBX and outer layer high velocity PBX. Concentration of tungsten powder in high density PBX was varied from 20 to 60% in mass. The pressure of overdriven detonation in inner layer PBX was measured by PMMA gauge, and was shown to be higher than 50GPa. The experimental results showed that the initial jet velocity and jet penetration velocity in target plates were largely increased by the effects of the overdriven detonation in tungsten loaded high density PBX.

A warhead requires the most suitable HE (High explosives). It is necessary to determine the optimal casing and HE in the development stage of the warhead by repetition of a series of process design, trial production, and testing. Accuracy of the simulation (Hydro-code) results also requires a practically usable level. However, we have asked for the JWL (Jones-Wilkins-Lee) parameters numerically by using KHT (Kihara-Hikita-Tanaka) code, since we have not experimental instruments like a streak camera and these experiments spend great deal of time and cost. For this reason, the simulation result was different from the experiment one slightly. Recently, we can ask for the JWL parameters experimentally, using the image converter camera of Kumamoto University by the joint research activities. We hope that the accuracy of these simulations might be raised by these studies. As sample explosives, PBX (Plastics bonded explosives) which used RDX or HMX, and Comp.C-4 were chosen. Further, new explosive of which detonation velocity was decreased by adding GMB (Glass micro balloon) to Comp.C-4 was made. These explosives were studied by KHT code and experiment, and JWL parameters were also gotten. As the result we could get several information, so it would be reported in this paper.

An insufficiency of a shock pressure in the materials processing [1] using the high explosive, has been removed by converging the shock wave. However, in the present material science field, the development of the device that generates ultra-high pressure is required. Therefore we have paid attention to the overdriven detonation phenomenon in the high explosive. The detonation pressure and velocity at the overdriven detonation state are higher than that of the Chapman-Jouguet state. For example the overdriven detonation can be caused, when the flyer plate collides with explosive and detonation is urged by the shock energy. However, it is difficult to apply this method to the dynamic consolidation of powder since the region where the overdriven detonation is generated is very small. Therefore, as a new method of generating the overdriven detonation effectively, the double cylindrical high explosive using the two kinds explosive was developed. The concentric double cylindrical high explosive was composed of a high velocity explosive and a low velocity explosive, and the overdriven detonation was caused in the low velocity explosive. The detonation velocity was measured by using the optical fibers. The detonation pressure was also measured by setting up a manganin gauge (Kyowa Electric Instrument Co., Ltd.,) at the position where the generation of the overdriven detonation phenomenon was expected. Furthermore the detailed propagation process of the detonation wave was calculated by the numerical analysis.