Determination of Delay in Detonation of a Sandwiched Explosive Impacted by a Shaped Charge Jet

  • H. S. Yadav DRDO-High Energy Materials Research Laboratory, Pune -  411 021
Keywords: Shaped charge Jet, Virtual origin, Explosive sandwich, Detonation delay, Plate velocity, Jet shifting, Standoff distance, Jet penetration


A simple analytical model has been developed to determine delay in detonation of an explosive sandwiched between two metal plates and impacted by a shaped charge jet. The analytical model consists of a relation between detonation delay and depth of jet penetration in a target kept in contact across the explosive sandwich. This relation is derived by expressing depth of jet penetration P as a function of detonation delay Tdx and duration Tw of free passage of the jet through the hole in the top plate of the sandwich. One more relation between Tdx and Tw has been obtained from the theory of expansion of hole produced in a metal plate by jet impact. These two relations have been solved simultaneously to get values of both these parameters as a function of jet penetration. It is proposed that this analytical model can be used in two ways. First, this model can be used to calculate detonation delay by experimental measurement of jet penetration in a target. The detonation delay thus determined can be used to calculate insensitivity constant Aj of an explosive. Second, this model can be used to theoretically calculate jet penetrations obtained by different shaped charge warheads when using a sandwich of explosive with a given insensitivity. Both uses of this analytical model are illustrated using numerical examples.


Walker, F.E. & Wasley, R.J. Critical energy of shock initiation of heterogeneous explosives. University of California, Lawrence Livermore Laboratory, 1968.

James, H.R. Critical energy criterion for shock initiation of explosives by projectile impact. Propell. Explos. Pyrotech., 1988, 13, 35-41.

James, H.R. Predicting the response of explosives to attack by high density shaped charge jets. J. Energ. Mater., 1989, 7(4-5), 243-264.

Yadav, H.S. Initiation of detonation in explosives by impact of projectiles. Def. Sci. J., 2006, 56(2), 169-177.

Held, M. Experiments of initiation of covered but unconfined high explosive charges with shaped charge jets. Propell. Explos. Pyrotech., 1987, 12, 167-174.

Chick, M.C. & Hutt, D.J. The initiation of covered composition B by metal jets. Propell. Explos. Pyrotech., 1983, 8, 121-126.

Yadav, H.S. & Kamath, P.V. Effect of a moving metal plate on jet penetration. Propell. Explos. Pyrotech., 1989, 14, 12-18.

Yadav, H.S. Interaction of a metallic jet with moving plate. Propell. Explos. Pyrotech., 1988, 13, 74-79.

Walters, W.P. & Zukas, J.A. Fundamentals of shaped charges. John Wiley and Sons Inc. 1989.

Held, M. Hydrodynamic theory of shaped charge jet penetration. Journal of explosives and propellants, ROC Taiwan, 1961, 7, 9-24.

Yadav, H.S. Flyer plate motion by thin sheet explosive. Propell. Explos. Pyrotech., 1988, 13(1), 17-20.

Yadav, H.S.; Sundaram, S.G. & Kamath, P. V. Study of an explosive driven metal plate. Propell. Explos. Pyrotech., 1986, 11, 16-22.

Held, M. & Kozhushko, A.A. Radial crater growing process in different materials with shaped charge jets. Propell. Explos. Pyrotech., 1999, 24, 339-342.<339::AID-PREP339>3.0.CO;2-5

How to Cite
Yadav, H. (2020). Determination of Delay in Detonation of a Sandwiched Explosive Impacted by a Shaped Charge Jet. Defence Science Journal, 70(4), 353-358.
Armaments & Explosives