Abstract:
A warhead device of an ordnance including a body of a high strength material, where the body includes a plurality of depressions; an explosive material, where the explosive material fills the body; and a plurality of reactive materials, where each reactive material fills a corresponding depression of the plurality of depressions on the body. The high strength material is configured to endure an internal stress, a first stress caused by the plurality of reactive materials, and a second stress caused by another component of the ordnance. The internal stress, the first stress, and the second stress are in response to acceleration of the ordnance.

Description:
GOVERNMENT INTEREST 
     The embodiments described herein may be manufactured, used, and/or licensed by or for the United States Government without the payment of royalties thereon. 
    
    
     BACKGROUND 
     Technical Field 
     The embodiments herein relate to weapons and more particularly to ordnance warheads. 
     Description of the Related Art 
     Existing munitions primarily rely on the detonation of an explosive to fragment and project a solid metal body (typically steel) towards a target. The interaction of the fragments and the target may lead to destructive effects that destroy or disable the target. Conventional warheads use inert materials that contribute no additional energy to the effect; the destruction of the target is exclusively dependent on the energy imparted on the fragment by the detonating explosive. 
     Lethality may be a function of the number of fragments projected, the area of the target that is vulnerable to damage from those fragments, and the probability that a fragment impacting that vulnerable area will cause the desired destructive effect. Consequently, the lethality may be dependent on the nature of the target and the impact area of the fragment on the body of the target. 
     The vulnerable area of a target may be limited to critical components or compartments of the target, and fragments that do not strike these vulnerable areas may not play a meaningful role in the destruction of the target. An example of this effect can be seen in fragments impacting a light vehicle such as a truck. Only fragments that strike critical areas such as the engine block or crew compartment may be relevant to the act of destroying or disabling the vehicle. If the fragments are inert, the fuel tanks of a vehicle are typically not considered part of the vulnerable area; a steel fragment will not ignite the fuel tank and may not cause a significant loss of fuel. 
     SUMMARY 
     In view of the foregoing, an exemplary embodiment herein provides a warhead device of an ordnance, the device including a body comprising of a high strength material, where the body includes a plurality of depressions; an explosive material, where the explosive material fills the body; and a plurality of reactive materials, where each reactive material fills a corresponding depression of the plurality of depressions on the body, where the high strength material is configured to endure an internal stress, a first stress caused by the plurality of reactive materials, and a second stress caused by another component of the ordnance, where the internal stress, the first stress, and the second stress are in response to acceleration of the ordnance. 
     The warhead device may further include a shock attenuating layer including a material configured to mitigate a shock effect, associated with detonating the explosive material, on the body. Each of the plurality of depressions may include a geometrical shape including any of a circular, square, and rectangular shape. The plurality of depressions may be arranged in a pattern configured to maximize a fragment distribution of the body. The plurality of depressions may be arranged in a pattern configured to minimize a stress on the body. The reactive materials may be configured to react in response to colliding with a target. The reactive materials may be configured to explode in response to colliding with a target. 
     Another embodiment provides a warhead device of an ordnance, the device including a body comprising of a high strength material, where the body includes a plurality of perforations; an explosive material, where the explosive material fills the body; and a plurality of reactive materials, where each reactive material fills a corresponding perforation of the plurality of perforations on the body, where the high strength material is configured to endure an internal stress, a first stress caused by the plurality of reactive materials, and a second stress caused by another component of the ordnance, where the internal stress, the first stress, and the second stress are in response to acceleration of the ordnance. 
     The warhead device may further include a shock attenuating layer comprising a material configured to mitigate a shock effect, associated with detonating the explosive material, on the body. Each of the plurality of perforations may include a geometrical shape including any of a circular, square, and rectangular shape. The plurality of perforations may be arranged in a pattern configured to maximize a fragment distribution of the body. The plurality of perforations may be arranged in a pattern configured to minimize a stress on the body. The reactive materials may be configured to react in response to colliding with a target. The reactive materials may be configured to explode in response to colliding with a target. 
     Another embodiment provides a warhead device of an ordnance, the device including a body comprising of a high strength material, where the body includes a plurality of hollow locations; an explosive material, where the explosive material fills the body; and a plurality of reactive materials, where each reactive material fills a corresponding hollow location of the plurality of hollow locations on the body, where the high strength material is configured to endure an internal stress, a first stress caused by the plurality of reactive materials, and a second stress caused by another component of the ordnance, whereas the internal stress, the first stress, and the second stress are in response to acceleration of the ordnance. The plurality of hollow locations may include any of depressions and perforations. 
     The warhead device may further include a shock attenuating layer including a material configured to mitigate a shock effect, associated with detonating the explosive material, on the body. Each of the plurality of hollow locations may have a geometrical shape including any of a circular, square, and rectangular shape. The plurality of hollow locations may be arranged in a pattern configured to maximize a fragment distribution of the body. The plurality of hollow locations may be arranged in a pattern configured to minimize a stress on the body. 
     These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating exemplary embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the exemplary embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The exemplary embodiments herein will be better understood from the following detailed description with reference to the drawings, in which: 
         FIG. 1  is a schematic diagram illustrating a warhead according to an embodiment herein; 
         FIG. 2A  is a schematic diagram illustrating depressions in a body of a warhead according to an embodiment herein; 
         FIG. 2B  is a schematic diagram illustrating perforations in a body of a warhead according to an embodiment herein; 
         FIG. 3A  is a schematic diagram illustrating reactive material in depressions of a body of a warhead according to an embodiment herein; 
         FIG. 3B  is a schematic diagram illustrating reactive material in perforations of a body of a warhead according to an embodiment herein; 
         FIG. 4A  is a schematic diagram illustrating circular hollow locations in a body of a warhead according to an embodiment herein; 
         FIG. 4B  is a schematic diagram illustrating square hollow locations in a body of a warhead according to an embodiment herein; 
         FIG. 4C  is a schematic diagram illustrating rectangular hollow locations in a body of a warhead according to an embodiment herein; 
         FIG. 5  is a schematic diagram illustrating a cross section of a body of a warhead, according to an embodiment herein; and 
         FIG. 6  is a schematic diagram illustrating a warhead according to an embodiment herein. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to, further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein. 
     Reactive materials may cause an energetic reaction upon impact with the target, and may offer increased lethality by increasing the vulnerable area of the target. Rcactive materials may be, for example, thermite-like pyrotechnic compositions of two or more nonexplosive solid materials. Reactive materials may stay inert and do not react with each other until they are subjected to a sufficiently strong mechanical, electrical, or laser stimulus. A mechanical stimulus may be for example colliding with the target. After a sufficient stimulus, the reactive materials may undergo fast burning or explosion with release of high amount of chemical energy in addition to their kinetic energy. 
     For example a reactive fragment impacting fuel tank of a target vehicle may have a high probability of igniting the fuel and causing a catastrophic effect. The increased vulnerable area of the target, coupled with the increased probability of a destructive effect from a fragment impacting that vulnerable area may results in increased warhead lethality. 
     A limitation associated with reactive materials may be their material strength. Reactive materials generally have low yield strengths that make them unsuitable for implementation in military munitions, which may experience acceleration loads that are tens of thousands times greater than that of gravity. A conventional technology, for example, describes a warhead with the entirety of reactive material. Under high acceleration loads of a warhead, reactive materials may deform and structurally fail, which leads to the loss of the warhead. 
     The embodiments herein provide an increased lethality warhead for high acceleration environments. Referring now to the drawings, and more particularly to  FIGS. 1 through 6 , where similar reference characters denote corresponding features consistently throughout the figures, there are shown exemplary embodiments. 
       FIG. 1  is a schematic that illustrates a warhead device  100  according to an embodiment. Warhead device  100  may be part of an ordnance. Warhead  100  may include a body  105 . In an embodiment, the body  105  is made of a high strength material. The high strength material may include metal, metal alloy, or ceramic materials. In an embodiment, the body  105  may have an elongated cylindrical shape. The body  105  may have other three-dimensional geometrical shapes, for example, conical, spherical, ellipsoidal, or any combinations thereof. 
     In an embodiment, the body  105  is patterned with hollow locations  110 . Hollow locations  110  may include any of depressions and perforations.  FIG. 2A , with reference to  FIG. 1 , is a schematic diagram that illustrates a sectional view of a portion of body  105  having depressions  110   a  according to an embodiment. The depressions  110   a  may be dents or engravings in the body  105 . Depth d 1  of any of the depressions  110   a  may be a value between zero and depth d 2  of the body  105 .  FIG. 2B , with reference to  FIGS. 1 through 2A , is a schematic diagram that illustrates a sectional view of a portion of body  105  having perforations  110   b  according to an embodiment. Perforations  110   b  may be holes in the body  105 . 
     In an embodiment, each depression or perforation  110  may be filled with reactive materials.  FIG. 3A , with reference to  FIGS. 1 through 2B , is a schematic diagram that illustrates depressions  110   a  filled with reactive materials  125  according to an embodiment.  FIG. 3B , with reference to  FIGS. 1 through 3A , is a schematic diagram that illustrates perforations  110   b  filled with reactive materials  125  according to an embodiment. 
     Hollow locations  110  may have circular, square, rectangular, triangular, rhombic, or some other geometrical shape so as to best withstand the acceleration loads.  FIG. 4A , with reference to  FIGS. 1 through 3B , is a schematic diagram illustrating circular hollow locations  110   c  on the body  105 , according to an embodiment.  FIG. 4B , with reference to  FIGS. 1 through 4A , is a schematic diagram illustrating square hollow locations  110   d  on the body  105 , according to an embodiment.  FIG. 4C , with reference to  FIGS. 1 through 4B , is a schematic diagram illustrating rectangular hollow locations  110   e  on the body  105 , according to an embodiment. 
     Hollow locations  110  on the body  105  may have a variety of patterns. The pattern of the hollow locations  110  may vary with different warhead profiles so as to maximize fragment distribution and minimize body stress. The pattern of hollow locations  110  may maximize the fragmentation distribution by dispersing the fragments in a manner that accommodates a unique orientation and circumstances (e.g. velocity, target location) of an ordnance. The pattern of hollow locations  110  may minimize the body stress by avoiding stress concentrations and providing rigid support to column loads. 
     In an embodiment, the strength of the high strength material of the body  105  is such that the body  105  is capable of enduring not only internal stresses of acceleration, but also the acceleration stresses of the reactive materials  125  acting upon it or any other components in the warhead such as a nose section or other features. Therefore, the reactive material may only need to support itself and does not play a structural role. 
     In an embodiment, the warhead is filled with an explosive material  115 . The physical and performance characteristics of the explosive material  115  may depend on the requirements of the munition. Explosive material  115  may, for example, include pressed or cast plastic-bonded explosives. 
     In an embodiment, a shock attenuating layer  120  is placed between the explosive material  115  and the body  105 . The shock attenuating layer  120  may include shock attenuating material to mitigate the shock effects associated with the detonating explosive on the body material. Shock absorbing material may, for example, include any of polymer linings, and foamed structures made out of metal, polymers, ceramic, or trapped powder layers including metals, polymers, and ceramic. 
       FIG. 5 , with reference to  FIGS. 1 through 4C , is a schematic diagram illustrating a cross-section of warhead  100  including explosive material  115 , shock attenuation layer  120 , and body  105 , according to an embodiment. 
       FIG. 6 , with reference to  FIGS. 1 through 5 , is a schematic diagram illustrating an ordnance  150  including warhead  100  including body  105  and other components, according to an embodiment. The warhead  100  may further include a nose section  130 , fuze  135 , and fins  140 .  FIG. 6 , as an example of hollow locations  110 , shows circular hollow locations  110   c  on the body  105 . Body  105  may include any other geometrical shapes or patterns of hollow locations  110 . 
     In an embodiment, the high strength support material in the body  105  may transport reactive material  125  to a target  200 . The warhead  100  may function through the detonation of the explosive material  115 . The warhead body  105  may be broken apart and the energy of the detonation is imparted into the fragments as kinetic energy. The distinct pockets of reactive materials may break apart into controlled fragments. The combination of inert fragments of body  105  and reactive materials  125  may impact against the target  200  and produce destructive effects that destroy or disable the target  200 . An aspect of this embodiment may be the increased lethality offered by the reactive material coupled to the increased survivability of the high strength material of the body  105 . In an embodiment, reactive material  125  may increase destructive effect of the warhead by increasing vulnerable area of targets (fuel tanks, rocket motors, munitions, etc). Lastly, in alternate exemplary embodiments, other materials, which are not specifically reactive materials, may be used to fill the depressions  110   a  also referred to as “pockets.” 
     The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of exemplary embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.