Corrugated ballistic armor

Abstract

Fibrous composites comprising corrugated elements having improved resistance to penetration by ballistic projectiles/threats. The composites of the invention are useful in vehicle and aircraft armor, breastplates, hand-held shields, helmets, architectural shields, explosion containment, explosion management and other applications.

1 . A ballistic-resistant article of manufacture having a plurality of corrugations and comprising a plurality of layers of high strength, high tensile modulus fibrous networks in a matrix, wherein the effective thickness T of the ballistic-resistant article, in proportion to the thickness dimension t of said plurality of layers of fibrous networks, is from about 1.2 to about 10, wherein  
     
     
         2 . The ballistic-resistant article of  claim 1  wherein said corrugations are vertically extending ridges and grooves formed alternately and having a smooth meandering waveform in a lateral direction.  
     
     
         3 . The ballistic-resistant article of  claim 1  wherein said corrugations are vertically extending ridges and grooves formed alternately and lying in essentially straight lines in a lateral direction.  
     
     
         4 . The ballistic-resistant article of  claim 1  wherein said corrugations are dimples and mounds in a planar neutral surface.  
     
     
         5 . The ballistic-resistant article of  claim 1  wherein the crest-to crest spacing L of said corrugations, in proportion to the thickness dimension t of said plurality of layers of fibrous networks, is from about 2 to about 30.  
     
     
         6 . The ballistic-resistant article of  claim 1  wherein each of said layers is comprised of a sheet-like array of fibers in which said fibers are aligned substantially parallel to one another along a common fiber direction.  
     
     
         7 . The ballistic-resistant article of  claim 5  wherein said layers have an arrangement in which the fiber alignment directions in selected layers are rotated with respect to the fiber alignment direction of another layer.  
     
     
         8 . The ballistic-resistant article of  claim 1  wherein, as measured by MIL-STD 662E dated 22 Jan. 1987, the specific energy absorption of a 9 mm, 124 grain FMJ bullet at the V50 velocity is more than about 10% greater than the specific energy absorption of a flat plate having the same layers of the same fibrous networks in the same matrix.  
     
     
         9 . The ballistic-resistant article of  claim 1  wherein, as measured by MIL-STD 662E dated 22 Jan. 1987, the specific energy absorption of a 9 mm, 124 grain FMJ bullet at the V50 velocity is more than about 20% greater than the specific energy absorption of a flat plate having the same layers of the same fibrous networks in the same matrix.  
     
     
         10 . The ballistic-resistant article of  claim 1  wherein a majority of said layers is comprised of fibers having a tenacity greater than about 17 g/d, a modulus of elasticity greater than about 300 g/d and an energy-to-break greater than about 20 J/g.  
     
     
         11 . The ballistic-resistant article of  claim 10  wherein said fibers are selected from the group consisting of polyethylene fibers, aramid fibers and polybenzazole fibers.  
     
     
         12 . The ballistic-resistant article of  claim 10  wherein said fibers are selected from the group consisting of polyethylene fibers, poly(p-phenylene terephthalamide) fibers and poly(p-phenylene-2,6-benzobisoxazole) fibers.  
     
     
         13 . A ballistic-resistant article of manufacture comprising: 
 a) an element having a plurality of corrugations, a front face and a rear face, said corrugated element comprising a plurality of layers of high strength, high tensile modulus fibrous networks in a matrix, wherein the effective thickness of said corrugated element in proportion to the thickness dimension of said plurality of layers of fibrous networks is from about 1.2 to about 10; and    b) a panel attached to at least one of said faces of said corrugated element.    
     
     
         14 . The ballistic-resistant article of  claim 13  wherein said panel is attached to said corrugated element at points that are spaced no closer than every alternate corrugation.  
     
     
         15 . The ballistic-resistant article of  claim 13  wherein the panel is selected from the group consisting of a ceramic, a metal, and a plurality of layers of high strength, high tensile modulus fibrous networks in a matrix.  
     
     
         16 . A ballistic-resistant article of manufacture comprising a front face, a rear face and a plurality of plies, each said ply having a plurality of corrugations and comprising a plurality of layers of high strength, high tensile modulus fibrous networks in a matrix, 
 wherein the effective thickness of each said corrugated ply, in proportion to the thickness dimension of the plurality of layers comprising the ply, is from about 1.2 to about 10, and wherein the direction of the corrugations in one ply are rotated with respect to the direction of the corrugations in another ply.    
     
     
         17 . The ballistic-resistant article of  claim 16  additionally comprising a panel forming at least one of the faces of said ballistic-resistant article.  
     
     
         18 . The ballistic-resistant article of  claim 16  wherein the ballistic-resistant article has out-of-plane curvature.  
     
     
         19 . The ballistic-resistant article of  claim 18  wherein the ballistic resistant article conforms to the surface of a human body.  
     
     
         20 . The ballistic-resistant article of  claim 1  wherein the ballistic-resistant article has out-of-plane curvature.