Multi-Functional Armor System

Abstract

A ballistic armor adapted to protect against armor piercing projectiles and to withstand multiple impacts of fragment simulating projectiles of a predetermined type, traveling at an initial velocity not exceeding a first velocity. The armor comprises a main armor layer and an auxiliary layer. The main armor layer is adapted to absorb most of the energy of the armor piercing projectiles and to withstand the impacts of the fragment simulating projectiles traveling at a velocity not exceeding a second velocity which is lower than said first velocity. The auxiliary layer is disposed in front of the main armor layer to face the projectiles, and is made of a material which is adapted to undergo a ductile failure mode when perforated by said fragment simulating projectiles and thereby experience localized deformation in the vicinity of each perforation, and which is adapted to cause the fragment simulating projectiles to experience such an energy loss associated with the perforation and deformation as to reduce their velocity from the initial velocity to a velocity not exceeding the second velocity.

1 . Ballistic armor adapted to protect against armor piercing projectiles and to withstand multiple impacts of fragment simulating projectiles of a predetermined type, traveling at an initial velocity not exceeding a first velocity, the armor comprising:
 (a) a main armor layer designed to absorb most of the energy of the armor piercing projectiles and to withstand the impacts of said fragment simulating projectiles traveling at a velocity not exceeding a second velocity which is lower than said first velocity; and   (b) an auxiliary layer disposed in front of the main armor layer to face the projectiles, the auxiliary layer being made of a material which is adapted to undergo a ductile failure mode when perforated by said fragment simulating projectiles and thereby experience localized deformation in the vicinity of each perforation; said auxiliary layer being adapted for being perforated by said fragment simulating projectiles such that an energy loss of the projectiles associated with said perforation and deformation gives rise to a reduction in their velocity from said initial velocity to a velocity not exceeding said second velocity.   
     
     
         2 . Ballistic armor according to  claim 1 , wherein the material of which the auxiliary layer is made is characterized in that its Brinell hardness is not greater than 165 kg f /mm 2 . 
     
     
         3 . Ballistic armor according to  claim 1 , wherein the material of which the auxiliary layer is made is characterized in that:
 (a) its elongation is greater than 8 percent; and   (b) its yield strength is not greater than 52 kg f /mm 2 .   
     
     
         4 . Ballistic armor according to  claim 1 , wherein the auxiliary layer is made of an aluminum alloy. 
     
     
         5 . Ballistic armor according to  claim 4 , wherein the aluminum alloy is a selected from the group comprising aeronautical alloys and commercial alloys. 
     
     
         6 . Ballistic armor according to  claim 1 , wherein the auxiliary layer is spaced less than 100 mm from the main armor layer. 
     
     
         7 . Ballistic armor according to  claim 1 , wherein the auxiliary layer is in contact with the main armor layer. 
     
     
         8 . Ballistic armor according to  claim 1 , wherein the fragment simulating projectiles are up to 20 mm in diameter and said first velocity is 1500 m/s. 
     
     
         9 . Ballistic armor according to  claim 1 , wherein the main armor layer comprises a base layer made of a high density material. 
     
     
         10 . Ballistic armor according to  claim 9 , wherein the high density material is high hardness steel. 
     
     
         11 . Ballistic armor according to  claim 10 , adapted for mounting on a sidewall of a vehicle to protect at least one region thereof, wherein said base layer is at least partially constituted by said sidewall at said at least one region. 
     
     
         12 . Ballistic armor according to  claim 1 , wherein the main armor layer further comprises an additional layer. 
     
     
         13 . Ballistic armor according to  claim 11 , wherein the main armor layer further comprises an additional layer which is in the form of an add-on layer mounted to said sidewall at said at least one region. 
     
     
         14 . Ballistic armor according to  claim 12 , wherein the additional layer comprises a plurality of pellets or tiles held together by a binder material. 
     
     
         15 . Ballistic armor according to  claim 14 , wherein the pellets or tiles comprise a refractory material. 
     
     
         16 . Ballistic armor according to  claim 14 , wherein the pellets or tiles comprise ballistic ceramic. 
     
     
         17 . Ballistic armor according to  claim 16 , wherein the ceramic is selected from the group comprising alumina, silicon carbide, silicon nitride, and boron nitride. 
     
     
         18 . Ballistic armor according to  claim 14 , wherein the pellets or tiles are made of ultra high hardness steel. 
     
     
         19 . Ballistic armor according to  claim 1 , wherein the main armor layer further comprises an inner protective liner attached thereto on its side facing away from said auxiliary layer. 
     
     
         20 . Ballistic armor according to  claim 19 , wherein the inner protective liner is fiberglass. 
     
     
         21 . Ballistic armor according to  claim 19 , wherein the inner protective liner comprises aramid. 
     
     
         22 . Ballistic armor according to  claim 19 , wherein the inner protective liner comprises high density polyethylene. 
     
     
         23 . Ballistic armor according to  claim 19 , wherein the inner protective liner comprises a hybrid material. 
     
     
         24 . Ballistic armor according to  claim 1 , wherein the main armor layer comprises dual hardness armor. 
     
     
         25 . A method of ballistic protection against armor piercing projectiles and multiple impacts of fragment simulating projectiles of a predetermined type, each traveling at its initial velocity not exceeding a first velocity, method comprising:
 (a) providing a main armor layer adapted to absorb most of the energy of the armor piercing projectiles and to withstand the impacts of said fragment simulating projectiles traveling at a velocity not exceeding a second velocity which is lower than said first velocity;   (b) providing an auxiliary layer made of a material which is adapted to undergo a ductile failure mode when perforated by said fragment simulating projectiles and thereby experience localized deformation in the vicinity of each perforation; and   (c) disposing said auxiliary layer in front of said main armor layer so as to face the projectiles and to cause said fragment simulating projectiles to experiences such an energy loss associated with said perforation and deformation as to reduce their velocity from said initial velocity to a velocity not exceeding said second velocity.