Projectile/target interaction with electric current flow along the target surface

We present possible schemes of electromagnetic protection of a target. We study a problem of a projectile interacting with the main plane of a target after additional protective layer is penetrated, which case is typical of conductor bus-bars of rail drivers. We perform theoretical analysis of a projectile/target interaction under unidirectional electric current conditions for the case where the kinetic energy of a projectile is sufficient for a molten-metal crater to form around the projectile head. For the analysis, a generalized thermodynamic criterion of fracture of solid bodies has been formulated. We use a projectile with a hemispherical head with the impact direction normal to the target surface. We calculate distribution of electromagnetic pressure in a layer of the molten metal and define a change in the resultant force of the material impact resistance due to electromagnetic forces. We have concluded that electric current deteriorates the strength characteristics of the material, insofar as an additional electromagnetic force is directed into the target depth, i.e., coincides with the direction of the projectile. © 2002 Plenum Publishing Corporation.