Influence of Intermediate Layers in Reactive Armour Modules on the Protection Capability

Explosive reactive modules can contain low-density foam between the reactive sandwiches in order to prevent sympathetic detonation between the sandwiches. In the present study, the influence of the intermediate material on the protection capability of the ERA modules has been investigated, with special interest on sandwiches with a lightweight rear plate that are designed to give a fast acceleration of the forwards moving plate in order to minimize the length of the precursor. The study showed that introduction of an intermediate material do influence on the protection capability of the armour and that it could be either an overall improvement or deterioration. The mechanisms that have to be balanced are the deceleration of the flyer plates, that decreases the protection capability, and the erosion of the jet tip while penetrating the intermediate material, which improves the protection capability. A simple solution to avoid the deteriorative effect is also discussed.