Various vehicular or stationary enclosures are designed to protect occupants from injury due to an explosion adjacent the enclosures. Often, these enclosures incorporate armor (e.g., iron plate, rolled steel, and synthetic materials such as para-aramid synthetic fiber, Ultra-high-molecular-weight polyethylene, and various ceramics, or any combination thereof) to achieve the desired level of protection. The type and thickness of the armor is often chosen to protect occupants from an expected maximum explosion energy.
However, due to the fragile nature of the human body, even when the armor is strong enough to withstand an explosion, occupants inside an enclosure may still be injured from overpressure waves transmitted through breaches in the enclosure, open windows or doors in the enclosures and/or directly through the enclosure outer bounds (e.g., through the walls, floor, ceiling, doors, windows, etc.) against air trapped within the enclosure. Many enclosures include devices to relieve this overpressure (e.g., doors that blow off or an opening with a plug that blows out of the enclosure). However, the overpressure relief devices may not have immediate effect, especially during a critical period immediately after the explosion when the overpressure waves may echo and rebound within the confines of the enclosure. The primary and echoed waves can reinforce one another and create greater overpressure waves that can further injure the occupants of the enclosures by causing damages to soft tissues (e.g., brain concussions). Further, the overpressure waves may also cause rapid changes in the enclosure outer bounds that are in contact with the occupants, which can further injure the occupants. Injuries such as broken bones may occur by due to a rapid change in the user's position adjacent the enclosure outer bounds.
As a result, armor is often over designed to prevent any deflection and/or breach of the enclosure and prevent overpressure waves from traveling through the enclosure. However, overdesign of armor results in rapidly increasing weight and cost. As a result, present armor types and combinations are ill equipped to prevent injuries to occupants of the enclosures caused by overpressure waves and/or deflections of the enclosure within cost and weight constraints.
Implementations described and claimed herein address the foregoing problems by providing an overpressure wave absorbing system with a deflectable planar layer with a matrix of deflectable protrusions extending there from having greater than fifty percent planar surface area. The deflectable planar layer with the matrix of deflectable protrusions may absorb a portion of an incoming overpressure wave and reduce a magnitude of the overpressure wave incident on a protective layer and/or reflected from the protective layer.
Other implementations described and claimed herein address the foregoing problems by placing a deflectable planar layer with a matrix of deflectable protrusions extending there from having greater than fifty percent planar surface area between a protective layer and an expected source of an incoming overpressure wave. The deflectable planar layer with the matrix of deflectable protrusions may absorb a portion of the incoming overpressure wave and reduce a magnitude of the overpressure wave incident on the protective layer and/or reflected from the protective layer.
Other implementations are also described and recited herein.
Blast overpressure (BOP), also known as high energy impulse noise, is a damaging outcome of explosive detonations and firing of weapons. Exposure to BOP shock waves alone can result in injury predominantly to the hollow organ systems such as auditory, respiratory, and gastrointestinal systems. The overpressure absorbing material disclosed herein is directed at cushioning, dissipating, and/or absorbing BOP.
While the vehicle 102 is depicted as a particular land vehicle, use of the overpressure absorbing material on other land vehicles (e.g., tanks, trains, civilian cars and trucks, etc.) and other vehicle types (e.g., aircraft, watercraft, spacecraft, etc.) is contemplated herein. In another implementation, the vehicle 102 is an individual person, while the armor 106 is the person's skin and/or body armor.
The overpressure absorbing material is readily deformable in order to absorb the rapidly applied energy from the explosion 108. In one implementation, the shock absorbing panels include one or more arrays of opposed hemispherical or hemi-ellipsoidal hollow cells attached to upper and lower sheets of material, as described in detail with regard to
While the vehicle 202 is depicted as a particular land vehicle, use of the overpressure absorbing material on other land vehicles (e.g., tanks, trains, civilian cars and trucks, etc.) and other vehicle types (e.g., aircraft, watercraft, spacecraft, etc.) is contemplated herein. In another implementation, the vehicle 202 is an individual person, while the armor 206 is the person's skin and/or body armor.
A similar combination of armor 206 and panel 204 may be used to protect occupants within a stationary enclosure that is fully or partially sealed and that is at risk of adjacent explosions (see e.g.,
The overpressure absorbing material is readily deformable in order to absorb the rapidly applied energy from the explosion 208. In one implementation, the overpressure absorbing material includes one or more arrays of opposed hemispherical or hemi-ellipsoidal hollow cells attached to upper and lower sheets of material, as described in detail with regard to
The overpressure absorbing material 304 is applied to the inside of the netting 314. In other implementations, the overpressure absorbing material 304 is applied to the outside of the netting 314. When the explosion 308 occurs, a breach 312 forms in the netting 314 and the overpressure absorbing material 304 and the overpressure absorbing material 304 absorbs a large portion of an incoming pressure wave 310 from the explosion 308. A pressure wave 316 that continues through the netting 314 is significantly reduced in magnitude from the initial pressure wave 310.
Used in conjunction with the armor on the vehicle 302, the overpressure absorbing material 304 reduces the magnitude of the pressure wave (i.e., moving from pressure wave 310 to pressure wave 316) against the vehicle 302 and may prevent the incoming pressure wave 316 from penetrating the vehicle 302 in sufficient magnitude to cause injury to the vehicle's occupants by deforming, absorbing, and dispersing energy from the explosion 308. A similar combination of netting 314, overpressure absorbing material 304, and/or armor may be used to protect occupants within a stationary enclosure that is at risk of adjacent exterior explosions (see e.g.,
While the vehicle 302 is depicted as a particular land vehicle, use of the overpressure absorbing material on other land vehicles (e.g., tanks, trains, civilian cars and trucks, etc.) and other vehicle types (e.g., aircraft, watercraft, spacecraft, etc.) is contemplated herein. In another implementation, the vehicle 302 is an individual person and the netting 314 or other protective layer surrounds the individual person.
The overpressure absorbing material 304 is readily deformable in order to absorb the rapidly applied energy from the explosion 308. In one implementation, the shock absorbing material 304 includes one or more arrays of opposed hemispherical or hemi-ellipsoidal hollow cells attached to upper and lower sheets of material, as described in detail with regard to
The overpressure absorbing material is readily deformable in order to absorb the rapidly applied energy from the explosion 408. In one implementation, the shock absorbing panels include one or more arrays of opposed hemispherical or hemi-ellipsoidal hollow cells attached to upper and lower sheets of material, as described in detail with regard to
A pressure wave 510 from the explosion 508 enters the structure 518 via the breach 512 (or other opening) and may resonate within the structure 518, causing injury to the structure's occupants. The overpressure absorbing material absorbs a large portion of the pressure wave 510, preventing a significant magnitude of the pressure wave 510 from being reflected off the interior walls of the structure 518, resonating within the structure 518, and causing injury to the structure's occupants, by deforming, absorbing, and dispersing energy from the explosion 508. As a result, reflected pressure waves within the structure 518 are absorbed rather than being reinforced. In some implementations, the magnitude of the explosion, especially combined with relatively weak walls 506, may transmit through the walls 506 by deflection of the walls 506 without breach 512 or other opening.
A similar combination of walls 506 and panels 504, 505 may be used to protect occupants within a mobile enclosure (e.g., a vehicle) that is fully or partially sealed and that is at risk of adjacent explosions (see e.g.,
The overpressure absorbing material is readily deformable in order to absorb the rapidly applied energy from the explosion 508. In one implementation, the overpressure absorbing material includes one or more arrays of opposed hemispherical or hemi-ellipsoidal hollow cells attached to upper and lower sheets of material, as described in detail with regard to
The following specifications apply to at least the example overpressure absorbing panels 600, 700, 800 of
Example materials for the overpressure absorbing panels include thermoplastic urethane, thermoplastic elastomers, styrenic co-polymers, rubber, Dow Pellethane®, Lubrizol Estane®, Dupont™, Hytrel®, ATOFINA Pebax®, and Krayton polymers. Further, the wall thickness of each protrusions may range from 5 mil to 10 mil. Still further, the size of each of the protrusions may range from 0.25 to 1.5 inches in diameter and 0.5 to 3.0 inches in height in a hemi-ellipsoidal implementation. Further yet, the protrusions may be cubical, pyramidal, hemispherical, hemi-ellipsoidal, or any other shape capable of having a hollow interior volume. Other shapes may have similar dimensions as the aforementioned hemi-ellipsoidal implementation. Still further, the protrusions may be spaced a variety of distances from one another. An example spacing range is 0.5 to 3.0 inches.
The overpressure absorbing panels may be manufactured using a variety of manufacturing processes (e.g., blow molding, thermoforming, extrusion, injection molding, laminating, etc.). In one implementation, the overpressure absorbing panels are manufactured in two halves, a first half comprises an upper material sheet with corresponding protrusions. The second half comprises the lower material sheet with corresponding protrusions. Individual protrusions of each of the two halves of the overpressure absorbing panels are then laminated, glued, or otherwise attached together. In another implementation, the overpressure absorbing panels are manufactured in one piece rather than two pieces as discussed above. The overpressure absorbing material may come in the form of flat or molded panels that are applied to surfaces of a vehicle, structure, or human body. The overpressure absorbing material may also come in a roll that is unrolled over a vehicle, structure, or human body. The overpressure absorbing material may also be flexible enough to conform to contours in a vehicle, structure, or human body.
Further, an overpressure absorbing panel according to the presently disclosed technology may include more than two matrices of protrusions stacked on top of one another (e.g., two or more overpressure absorbing panels stacked on top of one another). Still further, an overpressure absorbing panel according to the presently disclosed technology may include only one matrix of protrusions.
Line 910 is a measurement of the pressure transmitted through the bare metal panel in line with the test chamber (i.e., a shock tube). Line 915 is a measurement of the pressure transmitted through the same metal panel, but after having passed through overpressure absorbing material. Line 910 shows a peak transmitted pressure of approximately 55 psi. Line 915 shows a peak transmitted pressure of approximately 35 psi. As a result, the overpressure absorbing material reduces transmitted pressure waves through the metal panel by approximately 36%.
In an implementation where the panel covered with the overpressure absorbing material is properly interposed between an explosive blast and an individual, the results would be as if the blast were moved farther away since the overpressure absorbing material absorbs a substantial portion of the overpressure wave front from the main blast.
Line 920 is a measurement of the pressure reflected from the bare metal panel in line with the test chamber (i.e., a shock tube). Line 915 is a measurement of the pressure reflected from the same metal panel, but after having passed through overpressure absorbing material. In this implementations, the measurement is taken eight inches from the metal panel. Line 920 shows a peak reflected pressure of approximately 250 psi. Line 925 shows a peak reflected pressure of approximately 125 psi. As a result, the overpressure absorbing material reduces reflected pressure waves from the metal panel by approximately 50%.
In an implementation where the panel covered with the overpressure absorbing material may substantially reduce or eliminate the amplifying effect of being subjected to both primary and secondary pressure waves within an enclosure. In one implementation, the overpressure absorbing material would reduce the effects of the overpressure to be as an individual within an enclosure was instead in open air.
In an experiencing operation 1020, the enclosure experiences an overpressure wave generating event adjacent the exterior surface of the enclosure. In some implementations, an explosive device (e.g., an improvised explosive device (IED), RPG, mine, missile, bomb, etc.) impacts the exterior surface of the enclosure and explodes. In other implementations, the explosive device explodes in close proximity to, but not contact with the exterior surface of the enclosure. For example, countermeasures (e.g., a RPG screen, Phalanx close-in weapon system (CIWS), etc.) may cause the explosive device to explode prior to contacting the exterior surface of the enclosure, thus reducing (but not necessarily eliminating) the pressure wave incident on the exterior surface of the enclosure.
An absorbing operation 1030 absorbs a portion of the overpressure wave using the overpressure absorbing material. The overpressure absorbing material deflects from the overpressure wave, distributing and absorbing energy from the overpressure wave. As a result, lighter armor may be used with the overpressure absorbing material as compared to armor without overpressure absorbing material. In some implementations, the overpressure absorbing material is resilient and may withstand multiple explosions. In other implementations, the overpressure absorbing material permanently deforms and is replaced after every explosion for maximum effectiveness.
In an experiencing operation 1150, the enclosure experiences an overpressure wave generating event adjacent the exterior surface of the enclosure. In some implementations, an explosive device (e.g., an IED, RPG, mine, missile, bomb, etc.) impacts the exterior surface of the enclosure and explodes. In other implementations, the explosive device explodes in close proximity to, but not contact with the exterior surface of the enclosure. For example, countermeasures (e.g., a RPG screen, Phalanx CIWS, etc.) may cause the explosive device to explode prior to contacting the exterior surface of the enclosure, thus reducing (but not necessarily eliminating) the pressure wave incident on the exterior surface of the enclosure.
A permitting operation 1160 permits the overpressure wave to enter the enclosure. Permitting operation 1160 may occur due to a breach in the exterior surface caused by impact of one or more projectiles. Further, a window and/or door of the enclosure may be open, providing a path for the overpressure wave to enter the enclosure. An absorbing operation 1170 absorbs a portion of the overpressure wave within the enclosure using the overpressure absorbing material. The overpressure absorbing material absorbs energy from the primary and/or secondary reflected overpressure waves, distributing and absorbing energy from the overpressure wave. As a result, reflections, if any, of the overpressure wave within the enclosure are substantially reduced. In some implementations, the overpressure absorbing material is resilient and may withstand multiple explosions. In other implementations, the overpressure absorbing material permanently deforms and is replaced after every explosion for maximum effectiveness.
The above specification, examples, and data provide a complete description of the structure and use of exemplary embodiments of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. Furthermore, structural features of the different embodiments may be combined in yet another embodiment without departing from the recited claims.
The present application claims benefit of priority to U.S. Provisional Patent Application No. 61/347,305, entitled “Protection from Overpressure Inside a Vehicle” and filed on May 21, 2010, which is specifically incorporated by reference herein for all that it discloses or teaches.
Number | Date | Country | |
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61347305 | May 2010 | US |