MACRO-PATTERNED MATERIALS AND STRUCTURES FOR VEHICLE ARRESTING SYSTEMS

FIELD OF THE DISCLOSURE

Embodiments of the present disclosure relate generally to macro-patterned materials and methods of their use in connection with vehicle arresting systems. Certain embodiments provide 3-D folded materials, honeycombs, lattice structures, and other periodic cellular material structures, that can be used for arresting vehicles. The materials can be engineered to have properties that allow them to reliably crush in a predictable manner under pressure from a vehicle. The materials can be formed into various shapes and combined in various ways in order to provide the desired properties.

BACKGROUND

Aircraft can and do overrun the ends of runways, raising the possibility of injury to passengers and destruction of or severe damage to the aircraft. Such overruns have occurred during aborted take-offs or while landing, with the aircraft traveling at speeds up to 80 knots. In order to minimize the hazards of overruns, the Federal Aviation Administration (FAA) generally requires a safety area of one thousand feet in length beyond the end of the runway. Although this safety area is now an FAA standard, many runways across the country were constructed prior to adoption of this standard. These runways may be situated such that water, roadways, or other obstacles prevent economical compliance with the one thousand foot overrun requirement.

In order to alleviate the severe consequences of overrun situations, several materials, including existing soil surfaces beyond the runway, have been assessed for their ability to decelerate aircraft. However, soil surfaces are not the best solution for arresting moving vehicles (i.e. aircraft), primarily because their properties are unpredictable.

Another system that has been explored is providing a vehicle arresting system or other compressible system that includes material or a barrier placed at the end of a runway that will predictably and reliably crush (or otherwise deform) under the pressure of aircraft wheels traveling off the end of the runway. The resistance provided by the compressible, low-strength material decelerates the aircraft and brings it to a stop within the confines of the overrun area. Specific examples of vehicle arresting systems are called Engineered Materials Arresting Systems (EMAS), and are now part of the U.S. airport design standards described in FAA Advisory Circular 150/5220-22B “Engineered Materials Arresting Systems (EMAS) for Aircraft Overruns” dated Sep. 30, 2005. EMAS and Runway Safety Area planning are guided by FAA Orders 5200.8 and 5200.9.

A compressible (or deformable) vehicle arresting system may also be placed on or in a roadway or pedestrian walkway (or elsewhere), for example, for purposes of decelerating vehicles or objects other than aircraft. They may be used to safely stop cars, trains, trucks, motorcycles, tractors, mopeds, bicycles, boats, or any other vehicles that may gain speed and careen out of control, and thus need to be safely stopped.

Some specific materials that have been considered for arresting vehicles (particularly in relation to arresting aircraft), include phenolic foams, cellular cement, foamed glass, and cellular chemically bonded phosphate ceramic (CBPC). These materials can be formed as a shallow bed in an arrestor zone at the end of the runway. When a vehicle enters the arrestor zone, its wheels will sink into the material, which is designed to create an increase in drag load.

However, some of the materials that have been explored to date can be improved upon. For example, phenolic foam may be disadvantageous in that is has a “rebound” characteristic, resulting in return of some energy following compression. Cellular concrete has density and compressive strength properties that may vary with time and that could be difficult to maintain in production due to the innate properties of its variable raw materials and subsequent hydration process. Foamed glass can be difficult to control in uniformity. It is thus desirable to develop improved materials for vehicle arresting beds.

BRIEF SUMMARY

Embodiments of the invention described herein thus provide systems and methods for designing vehicle arresting systems using macro-patterned materials or structures that can be engineered to have properties that allow them to reliably crush in a predictable manner under pressure from a vehicle. The materials can be formed into various shapes and combined in various ways in order to provide the desired properties.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top perspective view of one embodiment of a macro-patterned material, specifically a 3-D folded structure in a chevron pattern on an aluminum alloy sheet.

FIG. 2 shows a top perspective view of one embodiment of a macro-patterned material that is a 3-D folded structure in a chevron pattern on a different aluminum alloy material.

FIG. 3 shows a top perspective view of another embodiment of a macro-patterned material.

FIG. 4 shows a side perspective view of one embodiment of a machine that may be used to form folds or patterns on a material sheet.

FIG. 5A shows blocks formed from a plurality of macro-patterned material structures.

FIG. 5B shows a panel made from a plurality of blocks formed from a plurality of macro-patterned material structures.

FIG. 6 shows a block formed from a plurality of macro-patterned material structures.

FIGS. 7A-7H show alternate structure shapes that are within the scope of this disclosure.

FIG. 8 shows one embodiment of a honeycomb pattern.

FIG. 9 shows a schematic of a honeycomb pattern with outer panels on both sides of the honeycomb core.

FIG. 10 shows one embodiment of a honeycomb sandwich panel.

FIG. 11 shows one embodiment of a honeycomb sandwich panel with scored outer panels.

FIGS. 12A and 12B show a schematic of an aircraft wheel contacting the honeycomb embodiments, having varying orientation of cell axes.

FIG. 13 shows a schematic of stacked honeycomb blocks or panels.

FIG. 14 shows a schematic of adhesive layers that may be positioned between various structures that form a block.

FIGS. 15A and 15B show fire testing results for a honeycomb core and a honeycomb panel.

FIG. 16 shows various types of lattice structures that are within the scope of this disclosure.

DETAILED DESCRIPTION

Embodiments of the present invention provide materials that are designed in a way that renders them useful for arresting vehicles. In one aspect, the materials are provided as macro-patterned materials. As used herein, the phrase “macro-patterned materials” or “macro-patterned structures” is used to mean structures that are made of repetitive units in three dimensional (“3-D”) spaces. They may include minimum feature sizes for each unit that are equal to or larger than about 1 millimeter. The materials or structures may include 3-D folded materials, lattice structures, honeycomb structures, and any other type of periodic cellular structures.

As used herein, “periodic cellular material structures” refers to materials that have similar structures to those of periodic cellular metals (for example, those described in Haydn N. G. Wadley, “Multifunctional periodic cellular metals”, Phil. Trans. R. Soc. A (2006) 364, 31-68), but they are not limited to metallic materials. Such periodic cellular material structures can be made of any viable materials including metallic materials, ceramics, plastics, papers, and composites thereof, or combinations thereof. Furthermore, non-periodic cellular materials having the feature size defined above also fall into the scope of macro-patterned materials and structures.

In one example, the materials are folded three-dimensional structures. The structures may be formed by being folded or pressed or tessellated or otherwise engineered. These materials can be formed in any number of optional shapes and configurations and layers. In other embodiments, the materials are formed as lattice structures, a geometrical arrangement of objects or points, rods, sticks, inflatable structures, or any other structure, such as interlaced structures and patterns, honeycombs, and folded honeycombs.

The macro-patterned materials or structures described herein can be made of metals and alloys thereof, foils, plastics, paper, related materials, or combinations thereof More options are provided in the below description. Such materials or structures may be manufactured so that they exhibit energy absorbing capacities when tailored for use as vehicle arresting systems. By generating a dragging force from a vehicle wheel or other vehicle structure upon interaction with the materials, the kinetic energy of the moving vehicle can be absorbed so that the vehicle can be decelerated or stopped with minimal damage to the vehicle and with reduced to no injury to the vehicle occupants. By changing the geometric configurations and material properties of various materials or structures, moving vehicles of different weights can be safely stopped within predetermined ranges. (The vehicles that may be stopped include any land-based, wheeled moving systems, such as cars, trucks, bicycles, aircraft after landing or before taking-off, and so forth.)

Vehicle arresting systems refer to systems for installation at the ends of aircraft runways or other vehicle safety areas. They provide an external source of energy absorption. They are separate from the vehicle structure itself. Vehicle arresting systems are generally effective to safely decelerate vehicles entering the systems. They may be provided as a bed, a raised barrier, an indented area on a runway that is filled with materials, or any other appropriate system. The arresting systems disclosed are generally assembled of the macro-patterned materials and structures described herein.

The materials and structures may be engineered so that failure mode will meet desired performance requirements. For example, the pieces of material deform or break upon application of a force in a controlled way, such that they do not pose a severe hazard to the vehicle or its occupants. The materials are generally engineered to have desired properties for a wheel of an overrun aircraft to penetrate the material so that aircraft is stopped. In some examples, the materials may be considered “brittle.”

Additionally, federal regulations may dictate that the size of the resulting pieces from the broken or crushed materials or structures be such that they are small enough to not cause safety issues on a runway. Another example is that materials and structures may be engineered or treated to meet non-flammability requirements.

In one specific example, folding of flat sheets of materials into intricate 3-D structures has been found to provide a strength to density ratio that can be useful in arresting vehicles. As background, folded material structures and honeycombs have been developed and used for other applications, such as for acoustic applications for noise reduction, for protection in air drop of relief and aid supplies to reduce impact force (e.g., as an air drop cushion), as elastic shock absorbers, as building skeletons, or in packaging perfumes and other fragile items. The goal for each of these uses, however, is for the material to withstand an impact and to not shatter or break. By contrast, the desired intent of the materials described in this application is that they are designed to reliably crush in a controlled manner under impact from a vehicle so as to safety stop the vehicle, while minimizing injury to the vehicle occupants and damage to the vehicle.

One folding theory that may be used to provide the structures described herein is a sheet of material that is folded into a 3-D pattern. This can create a core structure 10, examples of which are shown in FIGS. 1-3. Once formed, the core structure 10 may be combined with other core structures 10 in various geometries and arrangements and patterns in order to provide the desired compressive strength, as outlined further below.

Scientists have developed mathematical theories that generate repetitive geometric patterns that can be folded from flat sheets. The theories generate an extensive variety of patterns, all of which are considered within the scope of this disclosure. (Many of these theories were developed and pioneered by D. H. Kling of Rutgers University, and are outlined in related literature published by Dr. Kling and his team. For example, processes for generating different patterns for various structures are described in the paper titled “Applications of Folding Flat Sheets of Materials Into 3-D Intricate Engineering Designs” by E. A. Elsayed and B. B. Basily of Rutgers University, the entire contents of which are incorporated by reference.)

Any type of folding technology may be used to form the core structures 10 described. Some examples include but are not limited to continuous folding using rollers, discrete folding using die, and vacuum folding. One example of a potential folding process is shown in FIG. 4. In this example, a sheet of material 12 may be pressed by rollers 14 in order to provide a raised pattern 16 or a creased pattern on the sheet. The sheet with a raised pattern may then be sent through another set of rollers—cross folding rollers—that are engraved with a pattern to create additional folds and patterns. More specifically, the sheet 12 may be pre-folded by being sent through a set of sequential circumferentially grooved rollers. The pre-folded sheet may then be sent through a set of cross folding rollers engraved with a specific pattern. This continuous folded sheet may they be cut into the desired dimensions. In some examples, the specific pattern may be a chevron-like or triangular pattern. The raised pattern 16 that is formed may be a chevron pattern, such as that shown in FIGS. 1-3. The chevron pattern may generally provide a series of nested V-shape features. In other examples, the raised pattern may be a mating surface (“MS”) pattern, as shown in FIG. 7A. The MS patter generally provides offset triangular faces. In other examples, the specific pattern may be a box pattern or a castellated pattern (FIGS. 7B and 7C), a curved or sin wave-like pattern, a chevron with flat surfaces (rather than points) (FIG. 7D), reflective (or star-like) surfaces (FIG. 7E), bearing surfaces reflector (FIG. 7F), or any other pattern. Additional non-limiting examples are shown in FIGS. 7G and 7H. Any other patterns are possible and are considered within the scope of this disclosure. Other examples of potential raised surfaces include but are not limited to a chevron pattern. Other patterns may include a honeycomb pattern and any other pattern that provides the desired energy absorbing properties.

In another example, a die may be created by forming and arranging desired tessellation units. Once the die is formed, a sheet of material having a specific dimension may be pressed against the die to form the desired folded shape. The resulting structure has the desired folded pattern.

In another example, a sheet of material may be subjected to heat and stretched. This method is particularly useful for polymeric, plastic, or composite material sheets. A vacuum may then be applied to force the malleable sheet against a die engraved with the desired folded pattern. Combinations of these techniques may also be used. Other methods of 3-D folding or forming 3-D folded structures are possible and considered within the scope of this disclosure.

The criteria to consider when determining what raised pattern to use include but are not limited to the desired impact strength, energy absorption, crush strength, compressive gradient, and any other factors. The material may be modified as desired as well. For example, materials may be selected having certain density and corrosion resistance, and may be formed with specific geometries and heights.

The properties of the final materials and the structure selected may be tailored through engineering. Changes may be made to the raw sheet materials, their thickness, folded pattern, and pattern geometry. Flexibility in design for selecting property and performance characteristics can allow better and more cost-effective use of materials for various applications.

For example, the sheet of material may be a sheet metal. The sheet of material may be a foil, a metal foil such as a foil of aluminum or copper or their alloys. The sheet of material may be paper, such as paperboard, fiberboard, corrugated material, fire resistant paper, or fiberglass reinforced composites. The material may be a plastic, such as thermoplastic materials, other polymers composite material, thermoplastic materials, polymers (including but not limited to polyethylene, polypropylene, polyvinyl chloride, polystyrene, acrylonitrile butadiene styrene), or a composite material, such as reinforced plastic or combinations thereof. The material may be a reinforced composite, a carbon fiber, a reinforced composite material, ceramic, cementitious materials, or combinations thereof

That material may be any combination of the above materials. It is also envisioned that other materials are possible and considered within the scope of this disclosure. Inflatable materials may also be explored and are considered within the scope of this disclosure. The material may be any appropriate material that can be deformed upon application of appropriate pressure, heat, or other means. The raw material properties may be selected to provide the desired crush strength. Parameters such as yield strength, ultimate strength, heat treating history, and chemical stability may be considered. In a specific example, 1100 series aluminum alloy has been tested and has shown good performance in various vehicle arresting applications.

One concept that the present inventors have identified is that for the structure (or a plurality of structures in combination) to reliably crush, it may be desirable for the pattern selected to be less anisotropic, such that it is generally uniform in most, if not all, directions. The core structure 10 may be formed so that its folds and other dimensions are generally similar across various cross-sections of the structure 10.

The structures are generally stacked or formed into larger structures that form the vehicle arresting system. In one example, the macro-patterned lattice, honeycomb or 3-D structured material is formed into a body that has a defined structure formed by the individual pieces. The macro pieces (which may be any shape, such as spheres, folded sheets, rods, flat panels, honeycomb panels, and so forth) may be placed in a set volume. This may be a box, a cube, stacked to form a certain body, assembled in layers, positioned in a bed, or any other option. They may have a defined position, such that there is a repetitive pattern. This repetitive pattern may be formed by stacked structures that may be oriented in different ways. In another example, the individual pieces or structures can be loose or attached by any means, such as being glued, welded, interlocked, or any other appropriate option. In short, the assembling is generally not random. The structures are not combined in any way, but are generally architected to create repeating patterns. This can assist with providing a system that provides reliable crushing from many directions.

The present inventors have also determined that certain thicknesses of the material also lend to its use as a vehicle arresting system. In one example, the thicknesses of the material prior to folding may range from about 0.003 inch to about 0.016 inch. In another example, the thickness of the material prior to folding may be from about 0.005 to about 0.015. In another example, the thickness of the material prior to folding may be less than about 0.5 millimeter, and particularly less than about 0.3 millimeter.

In one example, the height of the raised patterns 16 formed on the folded material may be from about 0.3 inch to about 2 inches. Specific ranges may be from about 0.4 inch to about one or 1½ inches. It is generally advantageous for this height to be uniform or otherwise generally consistent across the entire structure 10. This can allow the structure to reliably crush, no matter what part of it receives the impact. Providing an evenly distributed pattern can assist with the desired reliability of crushing upon impact.

As outlined above, the resulting structure 10 that is formed may also be stacked or layered with other structures to form a block 18 of core structures. Examples of a plurality of blocks or units of core structures are shown in FIGS. 5 and 6. The block 18 of core structures may be formed of structures 10 having the same materials and the same or similar geometry. In another example, the block 18 of core structures may be formed of structures having different materials and the same or similar geometry. In another example, the block 18 of core structures may be formed of structures having the same materials and different geometries. Any combination of these features may be used. As mentioned, one specific example provides structures 10 that have similar geometries, such that the block 18 of core structures is less anisotropic.

The structures 10 may be layered in any number of orientations. For example, in the example shown in FIG. 5A, the structures may be stacked on top of one another longitudinally. In another embodiment, they may be aligned in a side-by-side vertical-like arrangement, as shown in FIG. 6. An insert layer 20 may be inserted between each layer of stacked structures, as shown in FIG. 5A. Alternatively, the structures may be stacked directly against one another. In a further embodiment, the structures 10 may be twisted or rolled into a rounded unit or block. Any other configuration option is possible and is considered within the scope of this disclosure. The structures may have different top and/or bottom layers, different intermediate layers, or the layers may all be similar.

In one example, the structures 10 forming the layers may be glued to one another. In another example, the structures 10 forming the layers may be welded to one another. In another example, the structures 10 forming the layers may be cemented (using e.g., crushable nonflammable materials) to one another. Intermediate layers 20 may be glued and/or welded in place. It is possible to incorporate filler materials (not shown) in any areas of gaps in the folded structures 10. The filler materials may include but are not limited to stable, crushable, and non-flammable materials. Examples include a very lightweight ceramic foam. Further examples include a loose powder, a weak ceramic cement, a jelly, a foam, various types of sand, combinations thereof, and any other appropriate options. The filler may fill cavities of the macro-patterned structure, which may improve its performance and/or change the response behavior of the resulting vehicle arresting system.

In one specific embodiment, a block 18 may be made by orienting a plurality of the folded layers/structure 10 alternately in two different directions. These 2 directions may be perpendicular to one another. An intermediate layer, un-folded flat sheet 20 may be added between structures 10. This can help build (with adhesive or other means of bonding) block units 18. In one specific aspect, the block units 18 are about five cubic inches each. Other dimensions are possible and considered within the scope of this disclosure. For example, the blocks may range from 1 cubic inch to about 12 cubic inches in size.

These block units 18 can have less anisotropic compressive yield strength. For example, the strength difference in different directions may be less than 30%. Less anisotropy in compressive yield strength can be desirable in vehicle arresting performance. (It is anticipated that the vehicle may approach and contact the block 18 from one of any number of different directions). The block units 18 may then be arranged in a level and bonded with adhesive or other means of bonding with unfolded face sheet(s) 20. These intermediate layer sheets 20 may have a thickness of about 0.003-0.016 inches at top and/or bottom. In one aspect, the thickness of the intermediate layer 20 can be similar to or different from the thickness of the initial sheet used to make the folded structure 10.

Different levels of bonded units or blocks 18 can be bonded further, adding one level above another to form larger blocks. These blocks may be rectangular in shape, square, or any other appropriate dimension or shape.

FIG. 5A shows a plurality of units 18 that were built with folded structures 10, unfolded intermediate layers 20, a top layer 22 (unfolded), a bottom layer 24 (unfolded), and adhesives. In this example, each unit 18 is generally cube shaped and has one or more flat inter-layers or intermediate layers 20 in between any two adjacent folded structure 10 layers. The orientations of the folded structure 10 layers were alternate as described previously to achieve the same strength in two mutually perpendicular directions. Because materials may have different strengths in different directions, it may be desirable to reduce the strength difference by alternating layer orientations. The height of the folded structure layer is also determined from testing and achieved by selecting and using appropriate folding tools to minimize the difference in strength between lateral and vertical directions. Adjusting the parameters, such as thickness of the raw material sheet, the material of the sheet, height of the folds, interlayer thickness, and other parameters to obtain the desired material strength and reduced anisotropy of strength in different directions can be achieved. For example a range of folded layers may be from 0.3 to about 1.5 inches.

FIG. 5B shows a larger block 26 made of thirty six cube units 18, each of which is a cube 18 of 5 inch×5 inch×5 inch. For this example, adhesives are used to bond the cubes 18 together. In addition, face sheets 28 were bonded to the top and bottom of two levels of cube units 18. In between the two levels of cubes 18, there is also a large flat sheet 30 used to bond the two levels of cube units together. Apart from the large face sheets 28 and the large flat sheet 30 in between any two levels of the cubes, no additional bonding was used between adjacent cube units 18. It should be understood, however, that bonding adhesives or other securing materials may be used if desired. Higher blocks 26 may be made by adding more levels and a flat sheet 30 in between any adjacent levels. It should be understood that the heights and other aspects of the units 18 used in the block 26 need not be the same. For example, blocks of varying materials, varying geometries, and varying designs may be used. However, one benefit of using blocks 18 of similar materials, geometries, and designs may be that the larger block 26 that is formed is less anisotropic and may crush reliably and predictably.

FIG. 6 shows an embodiment in which the structures 10 are positioned vertically with respect to one another, so that there is a larger space between each intermediate layer than when they are positioned horizontally as shown in FIGS. 5A and 5B.

It should also be understood that the thicknesses of the face sheets 28 and flat sheets 30 may be varied to provide varying crush profiles. This can allow the units 18 or larger block 26 to be designed to meet various performance requirements, for example, in the case of the desired vertical strength change with height. The concept of using units 18 of certain sizes to build larger blocks 26 and controlling the bonding between units 18 in the blocks 26 can help ensure good failure mode during vehicle arrestment.

In the examples shown, a chevron pattern was tested. Although this pattern was found to provide test results that show good energy absorption characteristics for the intended application in vehicle arresting systems, it should be understood that other patterns may be used and are considered within the scope of this disclosure.

In other embodiments, the macro-patterned materials may be formed as lattice structures, honeycombs, folded honeycombs, or other periodic cellular structures. For example, a honeycomb structure 32 may be formed as a honeycomb-shaped cell structure 34 being sandwiched between two outer panels 36. An example of a honeycomb cell structure 34 is illustrated in FIG. 8. The cell sizes may range from about ¼ inch up to about one inch. It is possible for the cell sizes to be even larger, depending upon the materials used. The cell types may be rectangular, hexagonal, or any other appropriate shape. Honeycomb core structures typically have a load bearing capacity in one dimension and are extremely anisotropic in terms of mechanical properties. However, through engineering (such as, by adding face panel and adjusting the core height, or using folded honeycomb structures so that the final honeycomb structures can withstand load from different directions), the material can become less anisotropic.

The cell axes may be designed or oriented so that they have a crush strength that is similar from different directions. In one example, the material for the honeycomb-shaped cell structure 34 may be sheet or foil of metal or alloys such as aluminum or other metal alloy. The material may be plastic. The material may be paper, such as aramid paper, cardboard, or other options. The material may be ceramics, cementitious materials, composites, combinations thereof, or other appropriate material that may have the desired crushability aspects.

A schematic example of a honeycomb structure 32 with outer panels 36 is illustrated in FIG. 9. An actual example of a honeycomb structure 32 is shown in FIG. 10. The outer panels 36 may be made of the same or different material as the cell structure 34. The outer panels 36 provide a “skin” to the honeycomb structure 32 that provides a more rigid panel.

The gauge of the material(s) and/or the thickness of the material(s) may be optimized to provide the desired crushability of the resulting structure. For example, the gauge of the material may range from a thin aluminum foil thickness to a rigid sheet of metal. The thickness of the assembled honeycomb panels may range from about ¼ inch to about 40 inches in height H. In a specific embodiment, the panels are about 24 inches high. In another embodiment, assembled blocks of multiple panels may be up to about 40 inches high. It should be understood that the height can be varied to meet the needs, and heights higher than 40 inches are possible.

As shown in FIG. 11, the outer panels 36 may be scored or have one or more cuts 38 made in the skin of the panel 36. This can help enhance the energy absorbing features of the structures 32, either alone or as a combined structure 32. The scores 38 may be generally parallel as shown, or they may be random or at various directions. The scores or cuts have been shown to provide a desired drag load in testing.

FIG. 12 shows various options for the directions of the cell axes 40. In FIG. 12A, the cell axes 40 are angled at 22°. FIG. 12B, the cell axes 40 are angled at 45°. Tests have been conducted on 90° (vertical cell axis), 45°, and 22°. Under certain tests conditions, it was found that 45° worked well. However other angles may be used depending upon the expected engagement angle of the vehicle wheel. Scientific literature has established strength as a function of cell axis angle. It has been found that the strength of the honeycomb structure 32 may be a function of the cell axis 40. In these examples, the honeycomb structure 32 may be secured to a base panel B via any appropriate means. In one example, they may be secured to the base panel B via as adhesive. One or more honeycomb structures 32 may be placed end to end.

In another example, FIG. 13 shows that a plurality of honey comb structures 32 may be stacked to form a combined structure 42. In this example, the structures 32 may be stacked so that they create a raised area further along the runway. In one aspect, the stacked honeycomb structures 32 may be designed to have similar strengths. In another aspect, the stacked honeycomb structures 32 may be designed to have varying strengths. For example, there may be provided weaker honeycomb structures 32A on top for arresting lighter aircraft. Stronger honeycomb panels 32B may be provided as bottom or lower layers. All of the layers may be glued or otherwise adhered to one another via one or more adhesive layers 42.

FIG. 15 shows a series of fire testing results. FIG. 15A shows a honeycomb cell structure 34 without panels. FIG. 15B shows the structure 34 of FIG. 15A with panels 36 secured thereto. These results show that the honeycomb structure 32 provides the desired fire resistance. It is possible, however to provide a further fire resistant coating to the panel, such as, for example, a coating of Temprotex® or other fire or corrosion resistant material.

Another example of a macro-patterned material that may be used according to this disclosure is a 3-D printed material that is printed in layers. The desired macro-patterned material shape may be computer generated and then printed using any appropriate material(s). Additional materials may be useable with the 3-D printing option. For example, sand or loose pumice (when combined with a suitable binder) may be printed into the desired forms. The materials used should generally have the crushability parameters described, such that wheels of a moving aircraft will cause the material to crush or otherwise deform.

A further example of a macro-patterned material that may be used according to this disclosure is a lattice material that is formed via sticks that are connected to one another at various points to create a structure. Non-limiting examples of such lattice-type structures are shown in FIG. 16.

The material properties of the lattice structure can be tailored by changing lattice structure itself, the raw materials, or the size of the material components. Changes may also be made in the length, width or diameter of the sticks, the bonding strength at the joint points, as well as other parameters. For example, the compressive strength may be controlled to be about 3-100 psi, depending on the specific requirements for a vehicle arresting system application. For example, the density may range from about 2-50 pcf. For example, the lattice structure may have a component diameter or component cross-section feature size of about 0.001 to about 1.5 inches. One example of a possible lattice structure is a lattice truss structure.

Whether the vehicle arresting system is made from the 3-D folded materials or the honeycomb structures described, the macro-patterned materials may be stacked so that varying layers have varying levels of crushability. In one example, core structures may be arranged in a way that allows varying crushability at varying levels of the structure. For example, an outer layer may crush more easily than an inner layer, so that much of the damage to the structure occurs externally. As another example, the outer panel or layer may be scored more heavily or deeply, so that it creates more drag load. As another example, an outer layer of the system may be provided of different layers of materials having different strengths from lower materials in the same system. An optimal combination of these parameters may result in the maximum effectiveness of the structure as a vehicle arresting system. These features may be tailored for different airport requirements, runway sizes, and/or expected size of aircraft to be safely stopped.

The resulting structures and blocks of bodies formed therefrom may be formed into panels, blocks, beds, or any structure that can positioned at the end of a runway or road. The resulting vehicle arresting system may be secured in any appropriate way. The resulting vehicle arresting system may be covered or coated with any materials for such purpose.

Changes and modifications, additions and deletions may be made to the structures and methods recited above and shown in the drawings without departing from the scope or spirit of the disclosure or the following claims.

MACRO-PATTERNED MATERIALS AND STRUCTURES FOR VEHICLE ARRESTING SYSTEMS

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