Analysis of bar and net screens structure protecting vehicles against anti-tank grenades fired from RPG-7

The bar or net screens are ones of the methods to increase protection level of military vehicle crews against antitank grenades fired from RPG-7. Their task is to prevent generation of the shaped charge jet. The probability of vehicle's protection level when applying such types of screens depends on their structure - percentage share of the open space, i.e. space for which the flying grenade will not touch the structure element with its fuse, but it will be destructed. The two mechanisms are here mainly used: short circuit in the fuse circuit, deformation of conical section of the shaped charge warhead. This article presents analysis of structure of the bar and net screens due to share of the open space, for various impact angle of grenade in elevation and azimuth. The following were changed: thickness and width of bars and distance between them, thickness of wire and shape of individual net mesh. The solution of bar screen with the lowest weight and grenade destruction ability was selected. This solution was compared with the net screen offered currently on the market For the selected solutions, for angles increasing in elevation, up to 300 value, the bar screen has the larger open space than net screen. For angles in azimuth, the bar screen has larger open space for the entire range of angles. The bar screen is heavier by 50-60% when compared to the selected net screens, but their operation costs are lower. They are repaired in field conditions