Patent Application
20120186430
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.
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.
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.
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.
Certain embodiments of the invention may provide one or more technical advantages. A technical advantage of one embodiment may include the capability to add a tumble to the path of a projectile device. A technical advantage of one embodiment may include the capability to change the trajectory of a projectile device. A technical advantage of one embodiment may include the capability to slow down particles of a projectile. A technical advantage of one embodiment may include the capability to withstand and resist multiple impacts from particles of a projectile device. A technical advantage of one embodiment may also include the capability to increase impact time. A technical advantage of one embodiment may also include the capability to lower the force exerted on one or more armor layers of an armor system. A technical advantage of one embodiment may also include the capability to decrease the overall impact of a projectile. A technical advantage of one embodiment may also include the capability to decrease the shape change ability of a projectile and force the projectile to reshape itself based on the directionality of fibers used in armor system. A technical advantage of one embodiment may also include the capability to increase the surface area of the front of a projectile.
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.
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:
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.
Armor panels are generally used for armor against projectile 100. 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. Although
An easily yielding material may be used as armor against projectile 100. 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 against projectile 100. 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 projectile 100 is applied to dilatant material. When projectile 100 impacts with dilatant material, dilatant material may become very hard as if it were a solid and may provide great resistance to projectile 100. The greater the force caused by projectile 100 with dilatant material, the harder and more viscous dilatant material may become. For example, when projectile 100 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 projectile 100 to increase because the front of projectile 100 may become more flattened out while penetrating through dilatant material. After the surface area of the front of projectile 100 has increased as a result of traveling through dilatant material, the pressure applied to the next armor layer may be lowered because the force of projectile 100 is spread over a larger surface area. Thus, projectile 100 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 system 150 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 an incoming projectile 100. For example, projectiles 100, 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, since projectiles 100 may typically be fully constrained within the material of conventional armor systems, the projectile 100 may continue to stay aligned in its trajectory. However, when a projectile 100 is suddenly subjected to a layer of dilatant material in armor system 150 in accordance with embodiments of present disclosure, the projectile 100 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 allow armor system 150 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 panel 140, 155 may be impregnated with dilatant material, which may give the fiber made materials greater strength and resistance to projectile 100.
Composite armor panels 140, 155 may be comprised of one or more layers having composite fibers 120. Fibers 120 may be made of a variety of composite materials. Non limiting examples of composite materials that may comprise fibers 120 include e-glass, s-glass, an aramid fiber (e.g., Kevlar®), carbon nanotubes, carbon fibers, aluminum fibers and combinations thereof.
A composite armor panel 140, 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, fibers 120 of composite materials may be woven together and/or sewn together to form fiber layers or sheets. Woven sheets 130 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 fibers 120 (i.e., sheets) together to form composite armor panels 140, 155.
In some embodiments, for assembly of composite armor panels 140, 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 panel 140, 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 an armor system 150.
Composite armor panels 140, 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 panel 140, 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 of fibers 120 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 that fibers 120 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 panels 140, 155 of the disclosure may absorb energy from projectile 100 in a number of ways. In some embodiments, composite armor panels 140, 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,
In some embodiments, composite armor panels 140, 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 panels 140, 155 having different fiber directionality.
Teachings recognize that energy absorption may occur by physically breaking threads of fiber 120. Since fibers 120 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 of projectile 100. 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 panels 140, 155 may fail, as illustrated below in
Projectile 100 may initially have a cross-section of any shape, but projectile 100 may become fluidic and reshape into the most efficient geometry to penetrate armor system 150. According to some embodiments, armor system 150 may exploit this reshaping phenomenon by forcing the cross-section of projectile 100 to reshape into a shape substantially similar to the shape of the cross-section of the hole formed in composite armor panels 140, 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 projectile 100 to reshape itself in a shape different than the shape formed by projectile 100 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, and 155c) may force projectile 100 to reshape into a shape similar to a square or a rectangle. In some embodiments, projectile and/or the hole of composite armor panel 140, 155 may not reshape into a perfect square or perfect rectangle because there may be tumbling and variances of projectile 100. Composite armor panel comprising one or more sheets having a fiber directionality of [−45°/+45°] (e.g., 140a and 140b) 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 projectile 100 (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 system 150 may only partially reshape projectile 100 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, and 155c) and composite armor panels comprising one or more layers of composite fiber having a different fiber directionality (e.g., 140a and 140b), armor system 150 may force projectile 100 to reshape one or more times, which may require more fibers 120 to be broken, which may increase friction and energy absorption. For example, fibers 120 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) as many fibers 120 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 panels 140, 155. This increased amount of energy absorption by armor system 150 may mean that fewer armor panels are required to stop projectile 100, which may reduce the overall weight of armor system 150. The calculation of the square root of two is described below in
In some embodiments, teachings recognize that finer mesh may have more bonds that must be broken, which may increase the amount of energy absorption of armor system 150. In some embodiments, composite armor panels 140, 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 because more fiber threads 120 may need to be broken for the projectile to penetrate composite armor panels 140, 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 of fibers 120 and the way in which they are woven into sheets may contribute to performance of armor system 150. In some example embodiments, fibers 120 may be made from one or more of a variety of materials. In some example embodiments, fibers 120 may have various thicknesses d.
Teachings of certain embodiments recognize that armor systems 150 of the disclosure comprised of sheets having different fiber characteristics may be used to assemble composite armor panels 140, 155 having different projectile protection abilities. For example, in one embodiment, a sheet woven or stitched using thick fibers 120 may have a very different performance as compared to a sheet woven or stitched using very fine thin fibers 120 and/or a sheet woven or stitched using medium thickness fibers 120.
According to some embodiments, armor system 150 may be comprised of layers of thin composite armor panels 140, 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 that armor system 150 may provide protection or mitigate the effects of any other projectile type that may be operable to penetrate armor. Projectile 100 may initially have a cross-section of any shape, but projectile 100 may become fluidic and reshape into the most efficient geometry to penetrate armor system 150. According to some embodiments, armor system 150 may exploit this reshaping phenomenon by forcing projectile 100 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, and 155c) and composite armor panels comprising one or more layers of composite fiber having a different fiber directionality (e.g., 140a and 140b).
In some embodiments, the reshaping of projectile 100 may continue to absorb energy from projectile 100. In some embodiments, the energy of projectile 100 may determine the depth to which it will penetrate into armor system 150.
In some embodiments, composite armor panels 140, 155 may cause the front portions of projectile 100 to get worn away. Accordingly, the back portion of projectile 100 may become the natural cross-section of projectile 100. In certain embodiments, the back portion of projectile 100 may be a blockish shape having a cross-section greater in circumference than the front portion of projectile 100. In certain embodiments, composite armor panels 140, 155 may cause the projectile to lose mass as the front portions of projectile 100 get worn away.
As further depicted in
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 by projectile 100.
Finely woven high resin panels, which may be strong and rigid, have been a choice in several existing armor solutions for providing protection against projectiles 100. 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 of projectile 100. By increasing the dwell time of projectile 100 in armor system 150, projectile 100 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 on armor system 150 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 within armor system 150 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 an armor system 150 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 by projectile 100 on armor system 150 at any given point of time.
Other armor systems that do not use one or more composite armor panels 140, 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 panels 140, 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/ft2 or more depending on the type and size of armor used.
If vehicle 20 were equipped with any existing armor system or armor system solution, its maneuverability and effectiveness in protecting against projectiles 100 as described here may be diminished.
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.
