WO2008063702A2

WO2008063702A2 - Ballistic armor

Info

Publication number: WO2008063702A2
Application number: PCT/US2007/067538
Authority: WO
Inventors: Tirso E. Careaga; Pravin Borkar
Original assignee: Careaga Tirso E; Pravin Borkar
Priority date: 2006-04-26
Filing date: 2007-04-26
Publication date: 2008-05-29
Also published as: WO2008063702A3; WO2008063702A9

Abstract

One embodiment of the present invention relates to ballistic armor. Another embodiment of the present invention relates to a method of making ballistic armor. In one example, the ballistic armor may be for use with a vehicle (e.g., an automobile or a military 'tactical' vehicle). For the purposes of describing and claiming the present invention, the term 'strike face' is intended to refer to the material which faces the impacting projectile and the term 'back face' is intended to refer to the material behind the strike face material. Thus, the impacting projectile first strikes the 'strike face' material and then (to the extent that the impacting projectile penetrates the armor) the 'back face' material.

Description

BALLISTIC ARMOR

FIELD OF THE INVENTION

One embodiment of the present invention relates to ballistic armor. Another embodiment of the present invention relates to a method of making ballistic armor.

In one example, the ballistic armor may be for use with a vehicle (e.g., an automobile or a military "tactical" vehicle).

For the purposes of describing and claiming the present invention, the term "strike face" is intended to refer to the material which faces the impacting projectile and the term "back face" is intended to refer to the material behind the strike face material. Thus, the impacting projectile first strikes the "strike face" material and then (to the extent that the impacting projectile penetrates the armor) the "back face" material.

BACKGROUND OF THE INVENTION

Armor constructed from polymer-based ceramic composites is designed to defeat bullets, fragmentation and other long rod projectiles. Such projectiles may be fired from a firearm weapon or may be the result of an explosion of an explosive device such as a bomb, landmine or an IED.

Conventionally, armor composites have been constructed from materials which have a high density and/or mass (such as steel and ceramics). However, it is the armor community's goal to continuously develop armor designs which reduce the armor weight needed for defeating a given projectile. Thus, armor systems are being developed to defeat increasingly higher energy projectile threats (e.g., tungsten sabot rounds) against material composites with a lower weight / areal density. This is driven by the need for weight reduction of body armor (for the ease and convenience of the armor users) and in the case of land, sea and air vehicles, for accruing fuel savings and increasing allowable payload capacity. In this regard, various embodiments of the present invention may be utilized to enable armor (e.g., constructed from ceramic, metal, polymer and/or composite materials) to defeat bullets, fragmentation and/or IED threats at a lower system weight than comparable armor

Y 238385653v1 4/26/2007 1 systems made with essentially identical materials but constructed without using the geometric design aspects of the present invention.

BRIEF DESCRIPTION QF THE DRAWINGS Fig. 1 shows a perspective view (solid model) of an example single module for use in connection with an armor system according to one embodiment of the present invention;

Fig. 2 shows a perspective view (wire-frame model) of the example single module shown in Fig. 1;

Fig. 3 shows a perspective view (solid model) of an example array of modules of the type shown in Figs. 1 and 2;

Figs. 4-6 show an example hexagonal module (with Fig. 4 showing a perspective view of the example module; Fig. 5 showing a plan view of the example module of Fig. 4; and Fig. 6 showing a cross-sectional view of the example module of Fig. 4); and

Figs. 7-9 show an example decagon module (with Fig. 7 showing a perspective view of the example module; Fig. 8 showing a plan view of the example module of Fig. 7; and Fig. 9 showing a cross- sectional view of the example module of Fig. 7).

Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. The figures constitute a part of this specification and include illustrative embodiments of the present invention and illustrate various objects and features thereof.

Y238385653v1 4/26/2007 DETAILED DESCRIPTION QF THE INVENTION

Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the invention are intended to be illustrative, and not restrictive. Further, the figures are not necessarily to scale, some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

When a striking projectile impacts armor on the relatively sharp tip of the projectile, the kinetic energy of the projectile is transferred to the strike face of the armor material over a very small area (i.e., the area of the contact of the projectile tip and the strike face material). Of course, a certain strike face material weight/strength is required to sustain this high concentration of impact energy so as to not be penetrated (in order to defeat the impacting projectile).

The inventors have recognized, however, that if the impacting projectile were to impact the armor in a manner which increased the area of contact between the impacting projectile and the armor mass, the impact energy would be transferred to the armor mass over a larger area. Thus, the magnitude of energy transferred per unit area would be less than the prior case (i.e., when the projectile impacted the armor on the tip of the projectile). As a result of the lesser magnitude of impact energy transferred per unit area, the armor mass necessary to now defeat that energy would be less than in the prior instance.

In this regard, the present invention uses the physics described in the preceding paragraphs as the underlying concept and the basis for design of certain armor strike face geometries (see, e.g., the geometry of Figs. 1 and 2) which is expected to cause the impacting projectile to tilt and change its direction essentially immediately on impact. As a result, the contact area of energy transfer between the projectile and the armor strike face will increase and consequently, decrease the overall armor mass in the affected area that is necessary to defeat the impacting projectile. In other words, the present invention defines the design and the geometry of construction of the strike face material of the armor with the intention that the impacting projectile will tilt

Y238385653V1 <V26/2007 and change its course, thereby deliberately increasing the area of contact for mutual energy transfer and necessitating a lesser overall material mass (to cover the same protected area) to defeat the projectile and cause it to not penetrate the armor (or to penetrate less).

With reference now in particular to Figs. 1 and 2, it is seen that module 100 has on its strike face a number of flutes 101 A-IOlF, a concavity between each pair of adjacent flutes

101A-101F, and a number of discontinuities 103A-103F in each concavity between each pair of adjacent flutes 10 IA-I OIF. In addition, module 100 has on its strike face center projection 105. Of note, this geometry of module 100 (e.g., the flutes, concavities and discontinuities) is expected to cause the impacting projectile to tilt and change its direction essentially immediately on impact (as discussed above).

Of course, in other examples the modules may be of any desired shape (e.g., having a hexagon shape in plan view, an octagon shape in plan view, a decagon shape in plan view, a square shape in plan view, a rectangle shape in plan view).

With reference now to Fig. 3, it is seen that an array 300 comprising a plurality of modules 301E-301G of the type shown in Figs. 1 and 2 may be combined to cover and protect any desired area (the modules of the array may be attached together (e.g., via an adhesive and/or one or more mechanical fasteners) and/or the modules of the array may be attached to a vehicle or other surface (e.g., via an adhesive and/or one or more mechanical fasteners)).

In one example, the modules may be combined to build arrays measuring a maximum of approximately 120" x 240" in size. Of course, the arrays may use any desired number of modules and the arrays may be of any desired shape (e.g., having a hexagon shape in plan view, an octagon shape in plan view, a decagon shape in plan view, a square shape in plan view, a rectangle shape in plan view).

Referring now to Figs. 4-6 and Table 1 below, specific dimensions for an example hexagonal module are provided (Figs. 4-6 show the example hexagonal module, with Fig. 4 showing a perspective view of the module 400, Fig. 5 showing a plan view of the module 400 (along with dimensions "A", "B", "E" and "F" corresponding to Table 1) and Fig. 6 showing a cross-sectional view of the module 400 (along with dimensions "C" and "D" corresponding to Table 1).

Y 238385653V1 4/26/2007 Table 1

Of note, the minimum and the maximum dimensions given above are the lower and the upper end of the range of dimensions of this example (which may be used to design strike face units). The described range is fully applicable for selection of any of the points lying between the maximum and the minimum to arrive at appropriate designs in order to meet the desired threat spectrum.

Referring now to Figs. 7-9 and Table 2 below, specific dimensions for an example decagon module are provided (Figs. 7-9 show the example decagon module, with Fig. 7 showing a perspective view of the module 500, Fig. 6 showing a plan view of the module 500 (along with dimensions "A", "B", "E" and "F" corresponding to Table 2) and Fig. 7 showing a cross- sectional view of the module 500 (along with dimensions "C" and "D" corresponding to Table 2).

Y238385653v1 4/26/2007 Table 2

Again, the minimum and the maximum dimensions given above are the lower and the upper end of the range of dimensions of this example (which may be used to design strike face units). The described range is fully applicable for selection of any of the points lying between the maximum and the minimum to arrive at appropriate designs in order to meet the desired threat spectrum.

In another example, the module(s) and/or array(s) of ballistic armor may comprise one or more ceramic materials including (but not limited to): hot pressed boron carbide, aluminum oxide, reaction bonded boron carbide, hot pressed silicon carbide, reaction bonded silicone carbide, aluminum nitride, zirconia toughened alumina, sintered boron carbide, sintered silicon carbide, other carbide and oxide ceramics, and combinations thereof.

In another example, the module(s) and/or array(s) of ballistic armor may comprise one or more metal materials including (but not limited to): aluminum, boron, titanium, steel, and combinations thereof.

Y 238385653v1 4/26/2007 In another example, the module(s) and/or array(s) of ballistic armor may comprise one or more cermet materials involving a combination of metal(s) and ceramic material(s).

As described herein, as a projectile defeat strategy, it is desirable to cause the impacting projectile to tip essentially immediately on impacting the strike face in order that a larger area of the projectile contacts the strike face than just the tip of the projectile, thereby distributing the impact force over a larger area. This would result is lower stress per unit area of the strike face and increase the probability of defeat of the projectile threat. If the impacting projectile does not tip, the area of impact on the strike surface will be very small (projectile tip, followed by projectile diameter), resulting in very high local stresses in the strike surface at the point of projectile impact.

In this regard, one reason for the design (according to one embodiment of the present invention) of a number of repeating, wavy, curved surfaces, which fluctuate in a defined manner within a single module, is to significantly enhance the probability of tipping (change of direction) of the striking projectile. This is caused at least in part by the design of strike face surface to repeatedly change its direction (inversion) within a small area.

Of note, the present invention recognizes that the probability of tipping of the projectile is a function (at least in part) of the degree of undulations over a unit area of the surface and the amplitude and frequency of such undulations. The present invention also recognizes that the probability of projectile tipping depends (at least in part) upon the relation of the shape, dimensions and geometry of the projectile to those of the striking surface, technically, the amplitude, pitch and wave definition of each unit of the strike surface (curve defining the crest, the wave of the crests + valleys per unit of the strike surface). Further, the present invention recognizes that strike surface undulations which are dimensionally comparable to the dimensions and geometry of the impacting projectile have a greater probability of causing the projectile to tip than undulations which are a smaller fraction.

Moreover, the present invention recognizes that the strike face geometry could cause instantaneous interference to the striking projectile by a combination of factors such as offering a change in the obliquity of the strike surface in conjunction with providing a sufficient mass to defeat the striking projectile. The probability of defeat of the striking projectile is greater if the combination of thickness (mass) and surface geometry cause the projectile to tip and increase its

Y 23S385653v1 4/26/2007 surface area of contact between the two (i.e., between the projectile and the armor) supported by a sufficient mass of armor behind the tipped projectile to absorb the energy,

Absence of any of these factors - appropriate surface geometry or sufficient material mass would result in armor with a higher mass (lower mass efficiency) than in the present invention by virtue of the fact that the impacting projectile would transfer its entire kinetic energy to the strike surface over a very small area.

Accordingly, in another embodiment the present invention provides a basis to optimize the mass efficiency of the armor to defeat the striking projectile by application of a geometry which is specific to one or a combination of one or more projectiles. Further, in another embodiment the present invention provides undulations at the bottom as well as the top (e.g., decreasing mass and/or increasing the probability of projectile yaw in the course of its progress along/through the armor).

Further still, in another embodiment the present invention provides for changes in the frequency of the flute (fluctuation) in relation to the geometry of the striking projectile. The armor may be specifically designed to defeat the striking projectile by virtue of designing the armor's surface flute geometry to offer immediate and the highest interference to the striking projectile with the intent of forcing its change of direction.

Further still, in another embodiment the present invention provides for both front and rear surfaces of the strike face material to undulate (e.g., the present invention may maximize the mass efficiency of the strike face material through the design of a projectile-tipping geometry, on the front and the back of the strike face material).

In another embodiment the present invention defines the frequency, pitch and amplitude of undulation on a unit of the strike surface material at least in part as a function of the shape and dimensional geometry of the striking projectile. In another embodiment the present invention provides for: (a) recognition and definition of wave amplitude of the waves populating the module (single unit); and (b) recognition and definition of wave pitch populating the surface within a single module (or unit).

In another embodiment of the present invention more than one undulation per modular unit of the strike face may be provided. For example, rather than the top surface of a modular unit moving from the center to the periphery or vies versa in a single continuous curve, the

Y 238385653v1 4/26/2007 present invention may provide a modular unit has significantly higher number (frequency) of undulations per unit of strike face.

In summary, the geometry of the present invention may be utilized to defeat bullets and fragmentation projectiles at a lower weight (for a given area of protection) than a conventional armor system constructed from essentially identical materials. Conversely, the geometry of the present invention may be utilized to defeat higher energy bullets and fragmentation projectiles at essentially the same weight (for a given area of protection) as a conventional armor system constructed from essentially identical materials (of course, the specific geometry shown in the Figs, and described herein is intended to be illustrative, and not restrictive, and any armor geometry which causes the impacting bullet/projectile to tilt and change direction upon impact as described herein may be utilized).

While a number of embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, and not restrictive, and that many modifications may become apparent to those of ordinary skill in the art. For example, while the armor of the present invention has been described principally as ballistic armor, the armor may also (or instead) be designed to be resistant to blunt trauma, stab/slash threats and/or sharp/blunt weapons (e.g., knives, clubs, etc.). Further, the present invention may be used to provide different levels of protection in different regions of a vehicle (e.g., the armor in an upper portion of a vehicle may be configured to provide protection from small arms fire and the armor in a lower portion of the vehicle may be configured to provide protection from landmines and/or IED's). Further still, the armor of the present invention may be portable and may be capable of being moved to, from and/or between one or more vehicles. Further still, the geometry (e.g., the surface geometry) of armor according to the present invention may be applied to any material constituting the strike face of any armor system. Further still, the armor of the present invention may be used on the interior and/or exterior of a vehicle. Further still, while the present invention has been described primarily in connection with vehicle use, the present invention may be utilized for other purposes, such as personal body armor (e.g., bullet-resistant vests or other clothing). Further still, any steps relating to manufacture and/or use may be performed in any desired order (and any desired steps may be added and/or deleted).

Y 238385653V1 4/26/2007

Claims

What is claimed is:

1. A ballistic armor system, comprising: a module having a strike face and a back face; wherein the strike face of the module comprises: (a) a center projection; (b) a plurality of flutes extending from the center projection to a periphery of the module; and (c) a plurality of concavities, at least one of the plurality of concavities being disposed between each of an adjacent pair of the plurality of flutes.

2. The system of claim 1, further comprising at least one discontinuity disposed within each of the concavities.

3. The system of claim 1, wherein each of the concavities comprises at least one curved portion.

4. The system of claim 1, wherein each of the concavities comprises at least a first curved portion and a second curved portion, with a discontinuity disposed between the first curved portion and the second curved portion.

5. The system of claim 1 , wherein each of the concavities comprises at least one planar portion.

6. The system of claim 1, wherein each of the concavities comprises at least a first planar portion and a second planar portion, with a discontinuity disposed between the first planar portion and the second planar portion.

7. The system of claim 1, wherein the periphery of the module has a shape selected from the group consisting of: (a) a hexagon shape; (b) an octagon shape; (c) a decagon shape; (d) a square shape; and (e) rectangle shape.

8. The system of claim 1, wherein the module comprises at least one ceramic material.

Y 238385653v1 4/26/2007 10

9. The system of claim 8, wherein ceramic material is selected from the group consisting of: (a) hot pressed boron carbide; (b) aluminum oxide; (c) reaction bonded boron carbide; (d) hot pressed silicon carbide; (e) reaction bonded silicone carbide; (f) aluminum nitride; (g) zirconia toughened alumina; (h) sintered boron carbide; (i) sintered silicon carbide; (j) other carbide ceramics; (k) other oxide ceramics; and (1) combinations thereof.

10. The system of claim 1, wherein the module comprises at least one metal material.

11. The system of claim 10, wherein metal material is selected from the group consisting of: (a) aluminum; (b) boron; (c) titanium; (d) steel; and (e) combinations thereof.

12. The system of claim 1, wherein the module comprises at least one cermet material including a combination of at least one ceramic material and at least one metal material.

13. The system of claim 1, further comprising: at least one additional module; wherein the additional module has a strike face and a back face; and wherein the strike face of the additional module comprises: (a) a center projection; (b) a plurality of flutes extending from the center projection to a periphery of the additional module; and (c) a plurality of concavities, at least one of the plurality of concavities being disposed between each of an adjacent pair of the plurality of flutes.

14. The system of claim 13, wherein the module and the additional module are held adjacent one another with at least one mechanical fastener.

15. The system of claim 14, wherein the module and the additional module are held adjacent one another with adhesive.

16. A ballistic armor system for a vehicle, comprising: at least a first module having a strike face and a back face;

Y 238385653V1 4/26/2007 11 at least a second module having a strike face and a back face; and a mechanism to affix each of the first module and the second module adjacent one another on a surface of the vehicle; wherein the strike face of the first module comprises: (a) a center projection; (b) a plurality of flutes extending from the center projection to a periphery of the first module; and (c) a plurality of concavities, at least one of the plurality of concavities being disposed between each of an adjacent pair of the plurality of flutes; and wherein the strike face of the second module comprises: (a) a center projection; (b) a plurality of flutes extending from the center projection to a periphery of the second module; and (c) a plurality of concavities, at least one of the plurality of concavities being disposed between each of an adjacent pair of the plurality of flutes.

17. The system of claim 16, wherein the vehicle is selected from the group consisting of: (a) an automobile; and (b) a military vehicle.

18. The system of claim 16, wherein the first module and the second module are held adjacent one another using a mechanism selected from the group consisting of: (a) at least one mechanical fastener; and (b) adhesive.

19. The system of claim 16, wherein the first module and the second module are held on the surface of the vehicle using a mechanism selected from the group consisting of: (a) at least one mechanical fastener; and (b) adhesive.

Y 238385653v1 4/26/2007 12