US20120186430A1

Movatterモバイル変換

Info

Publication number: US20120186430A1
Application number: US12/652,366
Authority: US
Inventors: Alexander F. St. Claire; Timothy J. Imholt
Original assignee: Raytheon Co
Current assignee: Raytheon Co
Priority date: 2010-01-05
Filing date: 2010-01-05
Publication date: 2012-07-26

Abstract

According to one embodiment, an armor system includes one or more composite armor panels including one or more layers of fibers including a first fiber weave, such that a first directionality of one or more fibers of the first fiber weave is configurable to reshape a projectile based on one or more angles of the first directionality of the one or more fibers of the first fiber weave. The armor system also includes one or more composite armor panels comprising one or more layers of fibers including a second fiber weave, such that a second directionality of one or more fibers of the second fiber weave is configurable to reshape the projectile to a new shape based on one or more angles of the second directionality of the one or more fibers of the second fiber weave.

Description

TECHNICAL FIELD

This invention relates generally to the field of armor systems and more specifically to reshaping projectiles by light weight armor systems to protect against shape charges (e.g., an explosively formed penetrator (EFP)), other explosive devices, hypervelocity impacts and/or ballistic devices.

BACKGROUND

Improvised Explosive Devices (IEDs) and shape charges such as Explosively Formed Penetrators (EFPs) have accounted for a large number of combat casualties. Lethality of EFPs comes in part from the shape and arrangement of a concave copper cone, called the liner, which transforms into a forceful jet of fluidic metal which easily perforates steel armor. Despite focused efforts on armor development, Mine Resistant Ambush Protected (MRAP) vehicles and other armored vehicles still cannot defend against these threats. More recently, armor solutions such as the FRAG Kit 5 have been used to protect military vehicles such as Humvees. However, these armor solutions typically weigh around 200 lb/ft². Since nearly all army vehicles are thousands of pounds overweight, even without any additional armor protection solution, most of these approaches have proved impractical.

SUMMARY OF THE DISCLOSURE

According to some embodiments, the second directionality of the one or more fibers of the second fiber weave is configurable to reshape the projectile to a new shape based on one or more angles of the second directionality of the one or more fibers of the second fiber weave.

According to some embodiments, the resistance to the projectile is increased as a result of the projectile while breaking a portion of the one or more fibers of the second weave while the projectile is penetrating and reshaping.

According to some embodiments, the one or more fibers of the first fiber weave and the second fiber weave comprise aramid fibers. According to some embodiments, the first composite armor panel of the one or more composite armor panels of the first fiber weave may include a different type of fiber than a second composite armor panel of the one or more composite armor panels. According to one or more embodiments, the armor system may further include an armor panel comprising a metal alloy.

Further technical advantages of particular embodiments of the present disclosure may include an armor system that is lighter weight than conventional armor. A lightweight armor system of the present disclosure may be capable of protecting against a similar threat as a heavier conventional armor system. Yet another technical advantage of one embodiment may be a relatively low cost solution to provide protection against a variety of projectiles and high velocity impacts. In particular, armor systems using composite armor panels having layers of composite fiber with different fiber directionality to reshape the projectile in accordance with the present disclosure may protect against a shape charge such as an EFP, other explosive devices such as IED's, other projectile threats, bullets, ballistic threats and/or forms of hypervelocity impact.

Various embodiments of the invention may include none, some, or all of the above technical advantages. One or more other technical advantages may be readily apparent to one skilled in the art from the figures, descriptions, and claims included herein.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows an armor system using composite armor panels comprising layers of composite fiber with different fiber directionality, according to one example embodiment;

FIG. 2A shows a cross-sectional view of a first layer of a composite armor panel comprised of fiber having a fiber directionality of [0°/90°] and a roughly circular shaped hole illustrating the initial hole caused by the penetration of the front end of a projectile with a circular shaped cross-section;

FIG. 2B shows a more detailed view of the cross-sectional view of the first layer of the composite armor panel comprised of fiber having a fiber directionality of [0°/90°] and a roughly octagon shaped hole illustrating the initial hole caused by the penetration of the front end of the projectile with a circular shaped cross-section;

FIG. 2C shows a cross-sectional view of the first layer of the composite armor panel comprised of fiber having a fiber directionality of [0°/90°] and a more roughly octagon shaped hole illustrating the hole's increase in size by the penetration of the middle part of the projectile;

FIG. 2D shows a cross-sectional view of the first layer of the composite armor panel comprised of fiber having a fiber directionality of [0°/90°] and a roughly square shaped hole illustrating the hole's increase in size by the penetration of the end part of the projectile;

FIG. 2E shows a cross-sectional view of the first layer of the composite armor panel comprised of fiber having a fiber directionality of [0°/90°] and a roughly square shaped hole illustrating the hole's increase in size by the complete penetration of the projectile;

FIG. 2F shows a cross-sectional view of a last layer of the composite armor panel comprised of fiber having a fiber directionality of [0°/90°] and a roughly square shaped hole illustrating the hole's increase in size by the complete penetration of the projectile;

FIG. 3A shows a cross-sectional view of a first layer of a composite armor panel comprised of fiber having a fiber directionality of [+45°/−45°] and a roughly square shaped hole illustrating the hole caused by the initial penetration of the reshaped projectile after exiting the previous layers of composite fiber having a fiber directionality of [0°/90°];

FIG. 3B shows a cross-sectional view of a last layer of the composite armor panel comprised of fiber having a fiber directionality of [+45°/−45°] and a roughly diamond shaped hole illustrating the hole caused by the penetration of the reshaped projectile;

FIG. 4 shows a vehicle comprising an armor system of the disclosure, in accordance with one example embodiment;

FIGS. 5A and 5B shows an exemplary path of an explosively formed penetrator (EFP) through a prior art armor system not using layers comprised of composite fiber having a different directionality, wherein,FIG. 5A depicts an example shallow-disk shaped EFP making contact with a first armor layer located on an outer side of the armor system andFIG. 5B depicts the EFP now formed into a missile shaped structure as it penetrates through layers of prior art armor layers;

FIGS. 6A,6B and6C illustrate an exemplary path of an EFP through one embodiment of an armor system of the disclosure as shown inFIG. 1 using composite armor panels having layers of composite fiber with different directionality whereinFIG. 6A depicts an example shallow-disk shaped EFP contacting an outer side of the armor system;FIG. 6B depicts the EFP as it penetrates through a first composite armor panel comprising layers of composite fiber having a fiber directionality of [0°/90°]; andFIG. 6C illustrates the EFP as it penetrates through a second composite armor panel comprising layers of composite fiber having a fiber directionality of [+45°/−45°], which may considerably slow the impact and increase the surface area of the front of the EFP, according to one example embodiment; and

FIG. 7 illustrates the calculation that up to a square root of two times as many fibers may be broken by exploiting the reshaping phenomenon.

DETAILED DESCRIPTION OF THE DISCLOSURE

It should be understood at the outset that, although example implementations of embodiments of the invention are illustrated below, the present invention may be implemented using any number of techniques, whether currently known or not. The present invention should in no way be limited to the example implementations, drawings, and techniques illustrated below. Additionally, the drawings are not necessarily drawn to scale.

Teachings of certain embodiments recognize that armor systems may be used to provide protection against and/or reduce impact of various projectiles such as but not limited to shaped charges, explosively formed penetrators (EFPs), IEDs, ballistic devices, other explosives and hypervelocity impacts. Armor systems of the disclosure may be used in conjunction with any vehicle, such as but not limited to, military vehicles, convoy vehicles and/or personnel carriers and may be useful to protect personnel and equipment in war zones.

On the battlefield, shape charges such as EFPs, also known as explosively formed projectiles, pose serious threat to equipment and personnel. EFPs and other shape charges may have the ability to pierce through the armor of a vehicle and injure or kill the occupants inside.

Various configurations of shape charges and EFPs have been developed and several are capable of penetrating extremely thick and heavy armor. Therefore, merely adding more armor layers to protect against a shape charge may result in a vehicle that is overweight and less effective on the battlefield. In accordance with a particular embodiment of the present disclosure, a lightweight armor system may be capable of stopping a projectile or significantly reducing its destructive capability.

While not wishing to be bound to any particular theory, the present section provides a brief description of how high energy explosives and shape charges may achieve their lethality. High explosives may be extremely powerful because of their ability to rapidly release energy in the form of heat and pressurized gas. The extremely fast rate at which this energy may be discharged gives a high explosive its strength. Rapid discharge of a large amount of energy into a small space in a short amount of time and may generate shock waves. For example, rapidly released energy may compress neighboring air or surrounding material that further increase its velocity. The compressed air may then rapidly propagate outward and create a shock wave.

When a high explosive is detonated, an explosion may begin at a small portion at the edge of the explosive. This explosion may create a shock wave that may propagate through the rest of the explosive. When this shock wave comes in contact with a portion of the high explosive that has not yet exploded the shock wave detonates the unexploded explosive. Thus, the additional explosion causes the shock wave to increase in velocity.

By exploiting the properties of a high explosive, in conjunction with certain geometric configurations, a more powerful and more focused blast may be accomplished. Shape charges utilize properties of high explosives and a conical geometric shape, lined with a metal liner, to achieve an explosion that can reshape material from the metal liner into a penetrating configuration at the same time accelerating it by a high energy explosion.

Inertial forces of a material (e.g., metal from a metal liner) that are being propelled by an explosion from rest to a hypervelocity may affect the molecular structure of the material. A hypervelocity may be a velocity of over 6,700 miles per hour. Acceleration from rest to a hypervelocity generates extremely high inertial forces. These inertial forces may be significantly greater than the molecular forces holding the particular material together. As a result, the material may change its form and may convert from a solid to a liquid with the dominating inertial forces guiding the flow of the material.

EFPs and other shape charges use these principles while unleashing their explosive power. A shaped charge may be able to, but not limited to, pierce a thickness of steel armor equal to six-times its diameter.

When a shape charge is detonated a shock wave that detonates the charge reaches the tip of its metal liner. The liner tip may accelerate forward due to inertial forces and reach a hypervelocity changing the solid metal into a fluid. As the shock wave pushes the liner metal fluid towards center and since there is already metal occupying the center, the metal gets pushed out in two directions, some of the metal gets thrust in the direction of motion and becomes part of the jet or the penetrating portion of the shaped charge, while the rest of the metal gets pushed back towards the explosive and becomes part of the slug, the slow bulky portion of the shaped charge.

The remaining part of the conical liner may take the shape of a flat sheet and the shock wave may then impart additional momentum to the flat sheet giving it a final solid push. The shaped charge finally detaches from its casing.

The fluid metal has a varying velocity with length velocity decreasing farther down. For example, a jet tip of the fluid metal may be traveling much faster than a slug. The result may be an ultra-fine long penetrator traveling at an extremely high speed which may go through armor with a thickness of about six times the diameter of the charge. In accordance with one embodiment of the present disclosure, the speed of the tip of a shape charge may be substantially decreased by reshaping the projectile using composite armor panels having layers of composite fiber with different fiber directionality within an armor system of the disclosure.

However, shaped charges are in general not as effective and efficient to pierce armor from a distance, since a jet of fluid material can continue to stretch and will eventually break apart before it contacts a distant target.

An EFP is a specific type of shaped charge designed to pierce armor from a distance. A wide range of EFPs have been designed depending on the desired effect. An EFP structure may provide a distinct aerodynamic advantage over shaped charges. EFPs are typically shaped as semi-spherical dishes (rather than conical shapes as described above) that may be covered by a metal liner. The metal liner may be copper, or any other suitable metal that behaves similar to a fluid when subjected to extremely high inertial forces.

By having a more shallow dish shape an EFP jet does not become quite as concentrated as a shape charge jet described in sections above. Often an EFP metal becomes a single slug rather than a separate slug and jet. A minor jet may be present near the tip, but for the most part, the slug does not have a defined shape. EFPs typically have a larger slug that stays together better, but may have lower penetration attributes. For example, an EFP may be able to pierce a thickness of steel armor equal to the charge diameter. However, an EFP liner may be concentrated together such that the metal does not break apart before it reaches its target, making it efficient to strike distant targets.

As set forth earlier, geometry of the curvature of the liner before detonation may control the shape an EFP changes into after detonation. Particular shapes may be found to provide optimum aerodynamic and penetration attributes. The shape of an EFP may be important to its ability to penetrate. An EFP with a smaller surface area may penetrate easier. This may be the result of the higher stress that the EFP imparts over a smaller surface area of the armor it is penetrating. This may result in greater penetration. In accordance with one embodiment of the present disclosure, surface area of the tip of an EFP may be increased by reshaping the projectile using composite armor panels having layers of composite fiber with different fiber directionality within an armor system of the disclosure. In some embodiments, increasing the surface area of the tip of an EFP may provide a technical advantage by making it easier to decrease and/or stop penetration by an EFP using a lightweight armor system.

An EFP may travel at hypervelocity regimes over 6,700 miles per hour. A shock wave that accelerates the metal liner to these types of velocities may cause the metal liner of an EFP to behave as if it were a fluid. Fluid effects caused by the inertial forces generated by the explosion may in part contribute to the EFPs ability to penetrate.

As the fluid from an EFP tip penetrates armor, the armor may exert a drag force upon the tip of the EFP. However, instead of transmitting this force throughout the entire EFP, as would occur if the EFP were a solid, the tip portion of the EFP that is subjected to the drag force, may fall away from the sides of a hole being created in the armor. Thus, instead of slowing down the entire EFP, only a small portion of the EFP may experience drag from the armor while the rest of the EFP maintains its velocity as it travels through the hole in the armor.

Additionally, as the portion of the metal tip gets dragged backwards by the armor, the EFP may reshape itself into a better penetrator. This may result when the edges of the EFP may be somewhat consumed as they are pushed to the rear of the EFP reshaping the EFP to become a thinner and more effective penetrator. For example, material from EFPs may be reshaped into a missile shape. The EFP, due to this reshaped form, effectively slides through the hole formed in the armor, as opposed to having large friction forces from the armor slow the entire EFP. Accordingly, an EFP effectively lubricates the armor walls through which it is penetrating and despite its poor initial shape, is effectively able to reshape and bore through thick armor. In some embodiments, an armor system of the present disclosure may use composite armor panels, which may include layers of composite fiber with different fiber directionality that may force the EFP to form into a new shape. By forcing the EFP to reshape itself into a new shape, armor system may increase the friction between the EFP and armor system, which may slow down the speed of the EFP.

In addition, an EFP during its hypervelocity flight may split into a series of metal blobs or metal particles comprising leaders that are smaller, but travel faster and slugs which may be slower and bulkier. Several leader particles such as a primary leader and a secondary leader and several slugs such as a primary slug and a secondary slug may be present. A good EFP normally has all these metal particles well aligned with out a large pitch or yaw. Accordingly, an armor to protect form such an attack must be capable of withstanding multiple impacts.

Much of the lethal damage from an EFP is due to the behind armor effects (BAE). When an EFP penetrates armor, it may launch spall into the vehicle. Spell refers to the fragments of armor that the EFP may cause to break off and accelerate into the interior of the vehicle. This material may be extremely hot and may be moving at an extremely high velocity. As a result, these armor fragments may hit nearly everything within every compartment including the personnel compartment of the vehicle and may cause extreme damage to the vehicle and equipment inside and injury or death to any occupants.

Damage from EFPs may also result from the overpressure blast that may send highly compressed air outwards at an extremely high velocity. The overpressure alone may cause blindness, deafness, and death. The overall effect of an EFP penetrating a vehicle may be similar to a fragmentation grenade being detonated within the vehicle.

In accordance with one embodiment of the present disclosure, an armor system configurable to reshape the projectile using composite armor panels having layers of composite fiber with different fiber directionality within an armor system of the disclosure may be capable of significantly reducing destructive capability of a shape charge, an EFP, a high explosive, as well as any high velocity impact by slowing the speed of the respective projectile device.

FIG. 1 shows a projectile100 and anexemplary armor system150 comprising three composite armor panels comprising one or more layers of composite fiber having a particular fiber directionality155a,155b,and155c,and two composite armor panels comprising one or more layers of composite fiber having a different fiber directionality140aand140b,according to one example embodiment. However, teachings recognize using an additional number or a fewer number of composite armor panels155 having a particular fiber directionality and/or composite armor panels140 having a different fiber directionality inarmor system150.

Armor panels are generally used for armor againstprojectile100. Armor panels may include one or more layers or sheets of material. Non-limiting examples of armor panels may include material comprising fiber made material, a metal alloy (e.g., steel, cast iron, titanium, etc.), easily yielding material, a dilatant material, etc. AlthoughFIG. 1 only shows composite armor panels140,155, the teachings of certain embodiments recognize thatarmor system150 of the disclosure may combine any combination of armor panels made of any material with one or more composite armor panels140,155.

An easily yielding material may be used as armor againstprojectile100. An easily yielding material may be a soft material, such as but not limited to a polycarbonate (e.g., a light weight plastic). Non-limiting examples of an easily yielding materials may include a material that may have very little structural support, such as but not limited to Styrofoam® and/or aerogels. An easily yielding material may be a material having strong structural support such as but not limited to carbonized hard steel. An easily yielding material in some embodiments may also include a naturally strong structural material for example a material comprising different shapes such as but not limited to honeycombs, cylinders, or pyramids. Use of several other easily yielding materials not expressly described herein are also contemplated and the present disclosure is not limited in any way to the examples listed.

Dilatant material may also be used as armor againstprojectile100. Dilatant material may also be referred to as shear thickening material. Dilatant material may be a non-Newtonian fluid because dilatant material may not behave according to normal Newtonian fluid dynamics. Dilatant material may be in a liquid or solid state. Dilatant material under normal conditions are generally in a liquid state, but dilatant material may also look and act more like a solid under normal conditions. Dilatant material may be a material where its viscosity increases with the rate of shear force applied to the material. The dilatant effect may occur when closely packed particles are combined with enough liquid to fill the gaps between the particles. At low velocities, the liquid in the dilatant material may act as a lubricant, such that a slow moving object may move easily through dilatant material. However, at higher velocities, the liquid in dilatant material may be unable to fill the gaps between the particles, which may cause friction and viscosity to increase, such that a fast moving object may not be able to penetrate through dilatant material. Thus, the viscosity of dilatant material may increase when a force is applied to dilatant material. Non-limiting examples of dilatant material may include material comprising a mixture of corn flour and water, a mixture of sand and water, a mixture of polyethylene glycol and silica, etc.

Dilatant material may offer increased protection to armor system when the increased force from projectile100 is applied to dilatant material. When projectile100 impacts with dilatant material, dilatant material may become very hard as if it were a solid and may provide great resistance toprojectile100. The greater the force caused by projectile100 with dilatant material, the harder and more viscous dilatant material may become. For example, when projectile100 impacts with dilatant material, dilatant material may become as hard or harder than steel while weighing considerably less and being considerably less expensive than steel.

Layers of dilatant material may cause the surface area of the front of projectile100 to increase because the front of projectile100 may become more flattened out while penetrating through dilatant material. After the surface area of the front ofprojectile100 has increased as a result of traveling through dilatant material, the pressure applied to the next armor layer may be lowered because the force ofprojectile100 is spread over a larger surface area. Thus, projectile100 may be stopped sooner because of the lower pressure applied to one or armor layers as a result of traveling through one or more dilatant material layers. As a result,armor system150 using dilatant material may require fewer layers of armor, which may result in lower weight and cost.

A layer of dilatant material may also throw off the trajectory of anincoming projectile100. For example,projectiles100, which may often be missile shaped, although not necessarily limited to missile shaped objects, while penetrating through conventional armor systems, may be subjected to forces that may cause them to spin out of axis. However, sinceprojectiles100 may typically be fully constrained within the material of conventional armor systems, the projectile100 may continue to stay aligned in its trajectory. However, when a projectile100 is suddenly subjected to a layer of dilatant material inarmor system150 in accordance with embodiments of present disclosure, the projectile100 may gain a tumble.

In some embodiments, dilatant material layers may be placed in a cavity formed between armor layers. In some embodiments, dilatant material layers may be at least 0.25 inches thick. In some embodiments, one dilatant material layer having a thickness of at least 0.25 inches may allowarmor system150 to remove an inch of steel to achieve similar protection, which may result in lower weight and cost.

In some embodiments, dilatant material may be mixed into another armor layer, such that these armor layers may receive similar benefits as discussed above for dilatant material. For example, one or more sheets of fiber of a composite armor panel140,155 may be impregnated with dilatant material, which may give the fiber made materials greater strength and resistance toprojectile100.

Composite armor panels140,155 may be comprised of one or more layers havingcomposite fibers120.Fibers120 may be made of a variety of composite materials. Non limiting examples of composite materials that may comprisefibers120 include e-glass, s-glass, an aramid fiber (e.g., Kevlar®), carbon nanotubes, carbon fibers, aluminum fibers and combinations thereof.

A composite armor panel140,155 of the disclosure may be made of composite materials, often abbreviated as composites. Composite materials may provide lower weight armor solutions as compared to steel counterparts. Composites comprising two or more distinct materials may be made or structured in a vast number of ways. The present disclosure is not limited in any way by the materials or methods by which composites may be made.

According to some embodiments,fibers120 of composite materials may be woven together and/or sewn together to form fiber layers or sheets. Woven sheets130 may be layered or stacked upon each other with a glue laid out in between each sheet. Glue (e.g., a resin) may be used to bind woven fibers120 (i.e., sheets) together to form composite armor panels140,155.

In some embodiments, for assembly of composite armor panels140,155, a plurality of layers or sheets may be placed in a machine that applies a large amount of heat and pressure which causes layers to bind together solidly. This process may form a solid composite armor panel140,155. A plurality of composite armor panels (e.g.,140a,140b,140n,155a,155b,155c,155n) may be further layered over each other to form anarmor system150.

Composite armor panels140,155 may be monolithic or polylithic. A monolithic composite armor panel may include one or more layers or sheets having the same type and thickness of fiber and the same weave characteristics (e.g., fineness of mesh and/or directions of the weaves). A polylithic composite armor panel may include one or more layers or sheets having a different type and/or thickness of fiber and/or different weave characteristics. For example, one distinguishing feature between a monolithic and a polylithic composition is that all sheets comprised in one monolithic panel have one respective direction of weave. For example, in a non-limiting embodiment, all sheets comprised in one monolithic composite armor panel may have a direction of weave (also called weave directionality) of [0°/90°] that may be used repeatedly to form a composite armor panel140,155 of a particular thickness (e.g., 0.5 inches or 1 inch).

In some embodiments, since the weave directionality is constant throughout a monolithic panel, the concentration of a resin in the panel is also substantially uniform.

Teachings recognize that in certain embodiments, for polylithic composite armor panels, one or more sheets comprised offibers120 may not be identical. For example, in one embodiment, each sheet may be comprised of two or more different types of fiber and/or weave characteristics. In another example embodiment, each sheet may be comprised of fibers of the same material but may have different fiber thickness and/or weave characteristics (e.g., fineness of mesh and/or directions of the weaves).

A direction of weave may describe the direction of a fiber in the weave. For example, a non-limiting example of a direction of weave is a [0°/90°] weave, which indicates thatfibers120 run in two directions, horizontally [0°] and vertically [90°]. Another example of a direction of weave is a quadraxial weave also referred to as a [0°/+45°/−45°/90°]s weave. This weave comprises fibers that run in four primary directions, hence “quadraxial”. The “s” is an abbreviation that refers to symmetric. The unabbreviated notation would be described as a [0°/+45°/−45°/90°/90°/−45°/45°/0°] weave. Directions of weaves are not limited to the examples described here and weaves in many other directions as known to one of skill in the art may be used in various embodiments described here.

Composite armor panels140,155 of the disclosure may absorb energy from projectile100 in a number of ways. In some embodiments, composite armor panels140,155 may absorb energy by friction, by delamination, and/or by breaking of molecules of the composite fibers.

Friction and energy absorption may be greatly increased by placing one or more composite armor panels comprising fibers having different fiber directionality adjacent to one another. For example,FIG. 1 illustrates an exemplary armor system comprising three composite armor panels155a,155b,and155ccomprising one or more layers of composite fiber having a particular fiber directionality (e.g., a [0°/90°] weave), and two composite armor panels140aand140bcomprising one or more layers of composite fiber having a different fiber directionality (e.g., a [−45°/+45°] weave), according to one example embodiment.

In some embodiments, composite armor panels140,155 having different fiber directionality do not have to be stacked directly adjacent to one another to achieve the advantages described in this disclosure. For example, armor panels comprising air gaps, steel alloys, easily yielding material, or dilatant material may be stacked between the two composite armor panels140,155 having different fiber directionality.

Teachings recognize that energy absorption may occur by physically breaking threads offiber120. Sincefibers120 may be laid out in multiple directions, fiber breaking may occur down the direction of the fibers that come into contact with the cross-section ofprojectile100. If a fiber break occurs downstream of an individual fiber, this particular fiber may flex backward with little energy absorption, which may influence how composite armor panels140,155 may fail, as illustrated below inFIGS. 2A-2F and3A-3B. Accordingly,armor systems150 which include composite armor panels140,155 comprising one or more layers of composite fiber having a particular fiber directionality may form holes of a polygon shape based on the breaks of the fibers caused byprojectile100.

Projectile

100 may initially have a cross-section of any shape, but projectile100 may become fluidic and reshape into the most efficient geometry to penetratearmor system150. According to some embodiments,armor system150 may exploit this reshaping phenomenon by forcing the cross-section of projectile100 to reshape into a shape substantially similar to the shape of the cross-section of the hole formed in composite armor panels140,155 caused by the breaking of the fiber along the fiber directionality. Accordingly, a second composite armor panel (e.g.,140a) having a different fiber directionality than the first composite armor panel (e.g.,155a) may force projectile100 to reshape itself in a shape different than the shape formed by projectile100 while penetrating the first composite armor panel (e.g.,155a). For example, a composite armor panel comprising one or more sheets having a fiber directionality of [0°/90°] (e.g.,155a,155b,and155c) may force projectile100 to reshape into a shape similar to a square or a rectangle. In some embodiments, projectile and/or the hole of composite armor panel140,155 may not reshape into a perfect square or perfect rectangle because there may be tumbling and variances ofprojectile100. Composite armor panel comprising one or more sheets having a fiber directionality of [−45°/+45°] (e.g.,140aand140b) may force projectile to reshape into a shape similar to a diamond, such that the directionality of the reshaped polygon is rotated.

In some embodiments, directionality of fibers may force projectile100 (e.g., EFP) into a rough polygon shape of eight sides or less. In certain embodiments, the polygon shape to be formed may be dependent upon the directionality of fibers. In certain embodiments, the polygon shape does not have to be a regular polygon shape (e.g., polygon shape may be a rectangle). In certain embodiments,armor system150 may only partially reshape projectile100 into a polygon.

By using composite armor panels comprising one or more layers of composite fiber having a particular fiber directionality (e.g.,155a,155b,and155c) and composite armor panels comprising one or more layers of composite fiber having a different fiber directionality (e.g.,140aand140b),armor system150 may force projectile100 to reshape one or more times, which may requiremore fibers120 to be broken, which may increase friction and energy absorption. For example,fibers120 may only fail in the 0° or 90° orientations for fiber weaves of this directionality and the fibers may only fail in the −45° or +45° orientations for fiber weaves of this directionality. In this example, by changing the directionality of fibers in composite armor panels, up to the square root of two times (e.g., around 1.4) asmany fibers120 may be broken, which may result in up to the square root of two times the amount of energy absorption or resistance by composite armor panels140,155. This increased amount of energy absorption byarmor system150 may mean that fewer armor panels are required to stop projectile100, which may reduce the overall weight ofarmor system150. The calculation of the square root of two is described below inFIG. 7.

In some embodiments, teachings recognize that finer mesh may have more bonds that must be broken, which may increase the amount of energy absorption ofarmor system150. In some embodiments, composite armor panels140,155 having a larger number of angles in the weave, such as a [0°/+45°/−45°/90°]s weave may be used advantageously for absorption of more energy becausemore fiber threads120 may need to be broken for the projectile to penetrate composite armor panels140,155.

Present teachings recognize that in some embodiments, delamination may require breaking of numerous bonds (e.g., the resin glue) all along the length of a composite sheet. Accordingly, present teachings may use delamination as an effective method of absorbing energy because it allows for a small impact zone to be absorbed over a large surface area.

In some embodiments, teachings recognize that resin concentration may change material properties of a composite. For example, use of more resin may cause an armor panel to be harder and less flexible. Teachings recognize that in certain embodiments, combination of resin concentration and/or fiber characteristics and/or weave characteristics may allow control of flexibility and hardness in composite armor panels of the disclosure.

Several features and characteristics offibers120 and the way in which they are woven into sheets may contribute to performance ofarmor system150. In some example embodiments,fibers120 may be made from one or more of a variety of materials. In some example embodiments,fibers120 may have various thicknesses d.

Teachings of certain embodiments recognize thatarmor systems150 of the disclosure comprised of sheets having different fiber characteristics may be used to assemble composite armor panels140,155 having different projectile protection abilities. For example, in one embodiment, a sheet woven or stitched usingthick fibers120 may have a very different performance as compared to a sheet woven or stitched using very finethin fibers120 and/or a sheet woven or stitched usingmedium thickness fibers120.

According to some embodiments,armor system150 may be comprised of layers of thin composite armor panels140,155 (e.g., the thin composite armor panels may have a thickness of less than or equal to 0.5 inches.)

Projectile

100 may be any high explosive device, such as but not limited to a shape charge, an EFP, an IED, a landmine, a high energy explosive, a ballistic device and/or any hypervelocity impact. However, teachings of certain embodiments recognize thatarmor system150 may provide protection or mitigate the effects of any other projectile type that may be operable to penetrate armor.Projectile100 may initially have a cross-section of any shape, but projectile100 may become fluidic and reshape into the most efficient geometry to penetratearmor system150. According to some embodiments,armor system150 may exploit this reshaping phenomenon by forcing projectile100 to reshape one or more times, which may increase friction and energy absorption, by using composite armor panels comprising one or more layers of composite fiber having a particular fiber directionality (e.g.,155a,155h,and155c) and composite armor panels comprising one or more layers of composite fiber having a different fiber directionality (e.g.,140aand140b).

In some embodiments, the reshaping ofprojectile100 may continue to absorb energy fromprojectile100. In some embodiments, the energy ofprojectile100 may determine the depth to which it will penetrate intoarmor system150.

In some embodiments, composite armor panels140,155 may cause the front portions of projectile100 to get worn away. Accordingly, the back portion of projectile100 may become the natural cross-section ofprojectile100. In certain embodiments, the back portion of projectile100 may be a blockish shape having a cross-section greater in circumference than the front portion ofprojectile100. In certain embodiments, composite armor panels140,155 may cause the projectile to lose mass as the front portions of projectile100 get worn away.

As further depicted inFIG. 1, anouter side151 ofarmor system150 may refer to a side ofarmor system150 that receives the initial impact ofprojectile100. Accordingly, in the example embodiment depicted inFIG. 1, composite armor layer155amay correspond to an armor layer located at a shallowest depth inarmor system150 and composite armor layer140amay refer to a first panel located adjacent or toward outer side151 (or toward a shallowest depth) ofarmor system150. Aninner side152 ofarmor system150 of the disclosure may refer to a side ofarmor system150 that is located away from the initial impact ofprojectile100. Accordingly, in the example embodiment depicted inFIG. 1, composite armor panel155cmay correspond to a deepest depth inarmor system150.

Existing armor systems operate on the hard to soft concept and often have hard metal armor panels for increased hardness. Teachings of present embodiments recognize that flexibility of a fiber system may result in more protection relative to a metal system. In some embodiments, flexible fibers in tension may perform significantly better than rigid fibers that may be sheered byprojectile100.

Finely woven high resin panels, which may be strong and rigid, have been a choice in several existing armor solutions for providing protection againstprojectiles100. However, harder panels placed toward initial impact sites in an armor system may absorb significantly less energy.

In contrast to present thoughts in the art, teachings of certain embodiments recognize the need for fine tuning the hardness and flexibility of armor panels in an armor system. Accordingly, some embodiments relate to having a more flexible armor panel in the front and a more rigid armor panel in the back for energy absorption purposes. In some embodiments, a flexible armor panel may increase dwell time and change the trajectory and shape change properties ofprojectile100. By increasing the dwell time ofprojectile100 inarmor system150, projectile100 may be reshaped easier by each layer of fiber, which may require fewer layers of composite armor. In some embodiments, one or more beehive shaped structures may be integrated into one or more layers of fiber to allow for crush zones.

In some embodiments, the more rigid armor panels placed may reduce the exerted force onarmor system150 may provide increased protection. Teachings of certain embodiments recognize that merely having a flexible armor panel may not sustain a larger force. Teachings of certain embodiments recognize and teach the balance between hardness and flexibility of armor panels for optimal protection.

Teachings of certain embodiments recognize that fiber thickness and weaves may be fine tuned and located at positions withinarmor system150 in relation to the direction and force of impact.

According to some embodiments, having a more flexible composite armor panel toward the outer side of anarmor system150 may allow for flexing backwards slightly following an impact thereby causing a longer dwell time and increasing the impact time, which may advantageously increase the friction and decrease the amount of force exerted byprojectile100 onarmor system150 at any given point of time.

FIG. 1 shows an example embodiment of anarmor system150 according to some embodiments of the disclosure. However, teachings recognize that other armor systems as described in the present disclosure may be made and/or modified and used.

FIG. 2A shows a cross-sectional view of a first layer of a composite armor panel155acomprised offiber120 having a fiber directionality of [0°/90°] and a roughly circular shaped hole illustrating the initial hole caused by the penetration of the front end of a projectile100 with a circular shaped cross-section. Although projectile100 may begin with a circular shaped cross-section, projectile100 may begin to act fluidly and may reshape according to the holes formed in composite armor panel155ato allow easier penetration. For a composite armor panel155ahaving a very fine weave, the initial hole caused by the front end of a circular shaped projectile100 may appear circular as illustrated.

FIG. 2B shows a more detailed view of the cross-sectional view of the first layer of the composite armor panel155acomprised offiber120 having a fiber directionality of [0°/90°] and a roughly octagon shaped hole illustrating the initial hole caused by the penetration of the front end of the projectile100 with a circular shaped cross-section. Due to the fiber directionality of [0°/90°], the fiber threads may only fail in two directions, horizontal and vertical. Accordingly, in certain embodiments, the actual initial hole caused byprojectile100 may be created with a stair step type shape as illustrated inFIG. 2B.

FIG. 2C shows a cross-sectional view of the first layer of the composite armor panel155acomprised offiber120 having a fiber directionality of [0°/90°] and a more roughly octagon shaped hole illustrating the hole's increase in size by the penetration of the middle part ofprojectile100. After the initial hole has formed, as illustrated above inFIG. 1B, the middle portions of projectile100 may begin to penetrate. In certain embodiments, the middle portions of projectile100 may have a cross-section with larger dimensions than the cross-section of the front end ofprojectile100. Accordingly, the middle and end portions of projectile100 may continue to enlarge the hole in composite armor panel. The weakest portion offibers120 may be the corner sections of the previously formed hole because the broken fibers may flex backwards partially. Accordingly, the corner sections of the hole may begin to fail in a more pronounced stair step shape as illustrated inFIG. 2C.

FIG. 2D shows a cross-sectional view of the first layer of the composite armor panel155acomprised offiber120 having a fiber directionality of [0°/90°] and a roughly square shaped hole illustrating the hole's increase in size by the penetration of the end part of the projectile100. The weakest portion offibers120 may be the corner sections because the broken fibers may flex backwards partially. Accordingly, the corner sections of the hole may continue to fail in a more pronounced stair step shape as illustrated inFIG. 2D.

FIG. 2E shows a cross-sectional view of the first layer of the composite armor panel155acomprised offiber120 having a fiber directionality of [0°/90°] and a roughly square shaped hole illustrating the hole's increase in size by the complete penetration of the projectile100. The rear portions of projectile100 may reshape into the shape of the hole as currently formed. In some embodiments, the reshaping ofprojectile100 may become more distinct as projectile100 penetrates additional layers of fiber of composite armor panel155a.

FIG. 2F shows a cross-sectional view of a last layer of the composite armor panel155acomprised of fiber having a fiber directionality of [0°/90°] and a roughly square shaped hole illustrating the hole's increase in size by the complete penetration of the projectile. After penetrating several layers of fiber, the front portions of projectile100 may have been worn away, such that the cross-section of the back portion of projectile's100 blockish shape may become the natural cross-section ofprojectile100.

FIG. 3A shows a cross-sectional view of a first layer of acomposite armor panel140A comprised offiber120 having a fiber directionality of [+45°/−45°] and a roughly square shaped hole illustrating the hole caused by the initial penetration of the reshaped projectile after exiting the previous layers of composite armor panel having a fiber directionality of [0°/90°]. By using a composite armor panel140ahaving a different fiber directionality than the current shape ofprojectile100,armor system150 may be able to exploit the square shaped projectile100 because now up to a square root of two times as many fibers may be broken along the fiber directionality of [+45°/−45°], which may result in up to the square root of two times the amount of energy absorption by composite armor panel140a.This increased amount of energy absorption byarmor system150 may result in fewer armor panels are required to stop projectile100, which may reduce the overall weight ofarmor system150. The calculation of the square root of two is described below inFIG. 7.

FIG. 3B shows a cross-sectional view of a last layer of the composite armor panel140acomprised offiber120 having a fiber directionality of [−45°/+45°] and a roughly diamond shaped (e.g., a square or rectangle that has been rotated) hole illustrating the hole caused by the penetration of the reshaped projectile. After penetrating several layers of fiber of composite armor panel140a,projectile100 may have been reshaped from a square to a diamond while breaking up to a square root of two times asmany fibers120 to reshape into new polygon caused by the new directionality offibers120. In certain embodiments,armor system150 may include composite armor panel155bhaving a fiber directionality of [0°/90°] that may be stacked behind composite armor panel140a,such thatarmor system150 may cause the diamond shaped projectile100 to reshape into a square shaped projectile100 while breaking up to a square root of two times asmany fibers120 to reshape into this new polygon.

FIG. 4 depicts avehicle20, such as but not limited to a military vehicle, that may be equipped with anarmor system150 having one or more composite armor panels140,155 having different fiber directionality in accordance with the present disclosure.Armor system150 may be located on exterior ofvehicle20. Occupants and equipment ofvehicle20 may be protected byarmor system150 from the penetrating effects of a projectile (not expressly depicted) which may targetvehicle20.Vehicle20 may be maneuverable and effective on a battlefield while it is equipped witharmor system150 in accordance with embodiments of the present disclosure.

Other armor systems that do not use one or more composite armor panels140,155 having different fiber directionality as taught herein may be considerably heavier and thicker. For example, conventional armor systems, without using one or more composite armor panels140,155 having different fiber directionality as taught in the present application, may be many inches thick at a minimum and may comprise layers of materials much heavier than dilatant material layers. In another example, the mere addition of two panels of armor to an existing conventional armor system may add an additional weight of about 20 lb/ft²or more depending on the type and size of armor used.

Ifvehicle20 were equipped with any existing armor system or armor system solution, its maneuverability and effectiveness in protecting againstprojectiles100 as described here may be diminished.

FIG. 5A depicts an example shallow-disk shapedEFP100 making contact with a first armor layer155aof a prior art armor system150bwhere first armor layer155ais located on anouter side151 of armor system150b.FIG. 5B shows an exemplary path ofEFP100 through a prior art armor system150bthat does not use one or more composite armor panels140,155 having different fiber directionality.FIG. 5B depicts penetration through armor layers155a,155b,and155cbyEFP100. As depicted,EFP100 is now reshaped into a missile shaped structure and slides through armor as it penetrates through layers of the prior art armor system150b.SinceEFP100 may be fully constrained within material of armor system150bthe EFP stays aligned on its trajectory through all the layers of the prior art armor system150b.

FIGS. 6A,63 and6C illustrate an exemplary path of an EFP through one embodiment ofarmor system150 of the disclosure as shown inFIG. 1 using one or more composite armor panels140,155 having different fiber directionality.FIG. 6A depicts an example shallow-disk shaped EFP contacting anouter side151 ofarmor system150.Armor system150 is configured similar toexemplary armor system150 shown inFIG. 1. In some embodiments,armor system150 as shown inFIGS. 6A-6C may be comprised on the exterior of avehicle20.

FIG. 6B depicts the EFP as it penetrates through a first composite armor panel155acomprising one or more layers of composite fiber having a fiber directionality of [0°/90°]. In some embodiments, penetrating through first composite armor panel155acomprising one or more layers of composite fiber having a fiber directionality of [0°/90°] may causeEFP100 to lose energy and/or cause a tumble in the path ofEFP100 and/or throwEFP100 off its trajectory and/or lower the force exerted on a following panel of armor155b,and/or may increase the overall energy absorbed by thearmor system150 and/or may significantly slowEFP100 and/or may increase the surface area of the front ofEFP100.EFP100, with the gained tumble, increased surface area, and loss of energy may re-collide with the next armor layer155bwith a reduced penetration ability.

FIG. 6C illustratesEFP100 as it penetrates through a second composite armor panel140acomprising layers of composite fiber having a fiber directionality of [+45°/−45°], which may considerably slow the impact and increase the surface area of the front of the EFP, according to one example embodiment. In some embodiments, forcingEFP100 to reshape from second composite armor panel140acomprising layers of composite fiber having a fiber directionality of [+45°/−45°] may further reduce the energy ofEFP100 and/or add another tumble and/or reduce speed and/or impact and/or increase surface area and/or destructive ability ofEFP100. In some embodiments, impacts with two or more composite armor layers140,155 having different fiber directionality may renderEFP100 unable or ineffective to penetrate composite armor layer155cleaving the occupants and equipment behind composite armor layer155cprotected. In some embodiments, one or more armor layers of different material and/or composite armor layers140,155 having different fiber directionality may increase the overall energy absorption capacity ofarmor system150.

FIG. 7 illustrates the calculation that up to a square root of two times as many fibers may be broken by exploiting the reshaping phenomenon. In some embodiments, fibers may only fail in the 0° or 90° orientations for fiber weaves of this directionality and the new directionality of fibers may only fail in the −45° or +45° orientations for fiber weaves of this directionality. In this example, by changing the directionality of fibers in composite armor panels, up to the square root of two times (e.g., around 1.4) asmany fibers120 may be broken, which may result in up to the square root of two times the amount of energy absorption or resistance by composite armor panels140,155. In this example, the square root of two is the ratio of the sum of the

legs

704,706 of a rightisosceles triangle702 divided by ahypotenuse708 of rightisosceles triangle702 where a width ofprojectile100 is one inch. This increased amount of energy absorption byarmor system150 may mean that fewer armor panels are required to stop projectile100, which may reduce the overall weight ofarmor system150.

Modifications, additions, or omissions may be made to the systems and apparatuses described herein without departing from the scope of the invention. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. The methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. Additionally, operations of the systems and apparatuses may be performed using any suitable logic. As used in this document, “each” refers to each member of a set or each member of a subset of a set.

Although several embodiments have been illustrated and described in detail, it will be recognized that substitutions and alterations are possible without departing from the spirit and scope of the present invention, as defined by the appended claims.

To aid the Patent Office, and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims to invoke paragraph 6 of 35 U.S.C. §112 as it exists on the date of filing hereof unless the words “means for” or “step for” are explicitly used in the particular claim.

Claims

1. An armor system comprising:

one or more composite armor panels comprising one or more layers of fibers comprising a first fiber weave, wherein a first directionality of one or more fibers of the first fiber weave is configurable to reshape a projectile based on one or more angles of the first directionality of the one or more fibers of the first fiber weave; and

one or more composite armor panels comprising one or more layers of fibers comprising a second fiber weave, wherein a second directionality of one or more fibers of the second fiber weave is configurable to reshape the projectile to a new shape based on one or more angles of the second directionality of the one or more fibers of the second fiber weave, wherein the resistance to the projectile is increased as a result of the projectile breaking a portion of the one or more fibers of the second weave while the projectile is penetrating and reshaping.

2. The armor system ofclaim 1, wherein the one or more fibers of the first fiber weave and the second fiber weave comprise aramid fibers.

3. The armor system ofclaim 1, wherein a first composite armor panel of the one or more composite armor panels of the first fiber weave comprises a different type of fiber than a second composite armor panel of the one or more composite armor panels.

4. The armor system ofclaim 1, further comprising an armor panel comprising a metal alloy.

5. armor system ofclaim 1, wherein the new shape of the projectile is a rough polygon shape of eight or less sides.

6. The armor system ofclaim 1, wherein the projectile is a shape charge, an explosively formed penetrator (EFP), an improvised explosive device (IED), a ballistic device or a hypervelocity impact.

7. The armor system ofclaim 1, wherein the directionality of the second fiber weave is a quadraxial fiber weave.

8. An armor system comprising:

one or more composite armor panels comprising one or more layers of fibers comprising a first fiber weave, wherein a first directionality of one or more fibers of the first fiber weave is configurable to reshape a projectile penetrating the armor system based on one or more angles of the first directionality of the one or more fibers of the first fiber weave; and

one or more composite armor panels comprising one or more layers of fibers comprising a second fiber weave, wherein a second directionality of one or more fibers of the second fiber weave is a different directionality than the first directionality of the one or more fibers of the first fiber weave, the second directionality of the one or more fibers of the second fiber weave is configurable to reshape the projectile to a new shape based on one or more angles of the second directionality of the one or more fibers of the second fiber weave.

9. The armor system ofclaim 8, wherein the resistance to the projectile is increased as a result of the projectile breaking a portion of the one or more fibers of the second weave while the projectile is penetrating and reshaping.

10. The armor system ofclaim 8, wherein the one or more fibers of the first fiber weave and the second fiber weave comprise aramid fibers.

11. The armor system ofclaim 8, wherein a first composite armor panel of the one or more composite armor panels of the first fiber weave comprises a different type of fiber than a second composite armor panel of the one or more composite armor panels.

12. The armor system ofclaim 8, further comprising an armor panel comprising a metal alloy.

13. The armor system ofclaim 8, wherein the new shape of the projectile is a rough polygon shape of eight or less sides.

14. The armor system ofclaim 8, wherein the projectile is a shape charge, an explosively formed penetrator (EFP), an improvised explosive device (IED), a ballistic device or a hypervelocity impact.

15. The armor system ofclaim 8, wherein the directionality of the second fiber weave is a quadraxial fiber weave.

16. An armored vehicle, comprising:

a vehicle having an armor system configurable to enhance resistance to a shape charge, an EFP, an IED, an ballistic device, an explosive device or a hypervelocity impact, the armor system comprising:

one or more composite armor panels comprising one or more layers of fibers comprising a first fiber weave, wherein a first directionality of one or more fibers of the first fiber weave is configurable to reshape the shape charge, the EFP, the IED, the ballistic device, the explosive device or the hypervelocity impact penetrating the armor system based on one or more angles of the first directionality of the one or more fibers of the first fiber weave; and

one or more composite armor panels comprising one or more layers of fibers comprising a second fiber weave, wherein a second directionality of one or more fibers of the second fiber weave is a different directionality than the first directionality of the one or more fibers of the first fiber weave, the second directionality of the one or more fibers of the second fiber weave is configurable to reshape the shape charge, the EFP, the IED, the ballistic device, the explosive device or the hypervelocity impact to a new shape based on one or more angles of the second directionality of the one or more fibers of the second fiber weave.

17. The armored vehicle ofclaim 16, wherein the resistance to the shape charge, the EFP, the IED, the ballistic device, the explosive device or the hypervelocity impact is increased as a result of the shape charge, the EFP, the IED, the ballistic device, the explosive device or the hypervelocity impact breaking the one or more fibers of the second weave while the shape charge, the EFP, the IED, the ballistic device, the explosive device or the hypervelocity impact is penetrating and reshaping.

18. The armored vehicle ofclaim 16, wherein the one or more fibers of the first fiber weave and the second fiber weave comprise aramid fibers.

19. The armored vehicle ofclaim 16, wherein a first composite armor panel of the one or more composite armor panels of the first fiber weave comprises a different type of fiber than a second composite armor panel of the one or more composite armor panels.

20. The armored vehicle ofclaim 16, wherein the new shape of the shape charge, the EFP, the IED, the ballistic device, the explosive device or the hypervelocity impact is a rough polygon shape of eight or less sides.