Field

[0001] The present invention relates to structural materials and, more particularly, to materials comprised of structural honeycomb.

Background

[0002] Honeycomb structures are natural or man-made structures that have the geometrical characteristics of natural honeycomb produced by bees. Honeycomb structures provide the optimum way to divide a surface into regions of equal area with the least total perimeter. Honeycomb structures minimise the amount of raw source material used and, therefore, also the associated structural weight and costs of manufacture. Honeycomb structures provide for minimal density and have high out-of-plane compression and shear properties. Because three sides of each hexagonal cell in the honeycomb join at each vertex, stresses in the structure resolve equally in three dimensions.

[0003] Man-made structural honeycomb is used in a variety of fields including for forming packaging, sporting goods and composite materials and are widely used in building and construction. Man-made honeycomb is also often used when flat or curved surfaces having a high specific strength are required. For example, man-made structural honeycomb is used in the aerospace industry for creating aluminium, fibreglass and advanced composite materials.

[0004] Man-made structural honeycomb may be created using expansion, corrugation and moulding methods. For example, one method involves glueing or welding together thin pre-shaped sheets of plastic or paper to create hexagonal cavities. These structures may then be bonded perpendicularly onto sheets to form a laminated panel of hexagonal cavities. Another method involves packing and heat bonding tightly packed plastic straws that are then sliced to create a honeycomb -like structure. Another method involves shaping sheets of thermoplastic material into half hexagons and then folding the sheets so that the half hexagons meet and then fusing them together. The maximum thickness and width of the honeycomb that can be produced using all of these methods is limited. [0005] Man-made structural honeycomb can also be produced by manufacturing individual hexagonal cells and then joining them together in a tessellating and interlocking manner. These methods, however, require complex connector assemblies to join the cells together. These assemblies are expensive to manufacture and also present points of weakness in the overall structure. Other known methods for forming structural honeycomb are also limited by the thickness and width of the honeycomb that can be made and many do not result in truly regular hexagonal cells being produced.

[0006] Iterative manufacturing methods, such as three-dimensional printing, can also be used to manufacture structural honeycomb but these methods are not suitable for low cost or mass produced honeycomb.

[0007] In this context, there is a need for improved structural honeycomb and methods for forming the same.

Summary

[0008] According to the present invention, there is provided a support member for fabricating structural honeycomb, wherein the support member comprises:

at least first, second and third elongate segments connected together end-to-end in a zig-zag arrangement;

first and second apertures formed in the support member, respectively, between the first and second elongate segments and between the second and third elongate segments, wherein each of the apertures is configured to receive an endmost portion of an adjacent support member; and

a pair of endmost portions, each of the endmost portions being configured to fit into an aperture of an adjacent support member.

[0009] The elongate segments may be connected such that an angle of 120 degrees is formed between the first and second elongate segments and between the second and third elongate segments.

[0010] Each of the apertures may be configured to receive an endmost portion of an adjacent support member, wherein the adjacent support member is substantially identical in shape to the support member. [0011] Each of the endmost portions may be configured to fit into an aperture of an adjacent support member, wherein the adjacent support member is substantially identical in shape to the support member.

[0012] The apertures may each be elongated and aligned such that longitudinal axes of the apertures extend transversely between two side portions of the support member perpendicular to a longitudinal axis of the support member.

[0013] The endmost portions of the support member may each be rectangular and the apertures may each comprise an elongate channel configured to receive a rectangular endmost portion of an adjacent support member.

[0014] The elongate channel may be aligned such that an angle of 60 degrees is formed between a vertical axis of the elongate channel and a longitudinal length of each of the elongate segments adjacent to the elongate channel.

[0015] The sidewalls of the elongate channel may be provided with buttresses formed between the sidewalls and the support member for reinforcing the side walls.

[0016] The buttresses may be tapered towards topmost ends of the sidewalls.

[0017] The elongate segments may be integrally formed and continuous with one another and a folded portion of the support member may form the elongate channel.

[0018] The folded portion may be formed such that the elongate channel protrudes vertically from the support member in one direction only.

[0019] The folded portion may be formed such that the elongate channel protrudes vertically from the support member in two opposed directions.

[0020] A metal apparatus may be disposed proximal to each of the apertures and the endmost portions of the support member may each comprise a magnet.

[0021] A first side portion of the support member may comprise one or more protrusions extending outwardly from the side portion and a second side portion of the support member may comprise one or more apertures configured to receive a protrusion extending from a first side portion of an adjacent support member when disposed in abutting contact with the support member. [0022] The present invention also provides structural honeycomb comprising a core layer comprised of a plurality of first support members connected together to form a plurality of hexagonal cells, wherein each of the first support members comprises the support member as described above.

[0023] The core layer may further comprise a plurality of second support members and a plurality of third support members, wherein:

each of the second support members comprises a pair of elongate segments connected together end-to-end with a pair of apertures formed, respectively, between the pair of elongate segments and at a peripheral end of the relevant second support member;

each of the third support members comprises a single elongate segment with an aperture formed at a peripheral end of the relevant third support member; and

the apertures of the second and third support members are each configured to receive an endmost portion of an adjacent support member in the core layer.

[0024] The apertures of the second and third support members may each comprise an elongate channel configured to receive a rectangular endmost portion of an adjacent support member in the core layer.

[0025] The elongate channels of the second support members may each be aligned such that an angle of 60 degrees is formed between a vertical axis of the relevant elongate channel and a longitudinal length of each of the elongate segments of the relevant second support member adjacent to the relevant elongate channel.

[0026] The elongate channels of the third support members may each be aligned such that an angle of 60 degrees is formed between a vertical axis of the relevant elongate channel and a longitudinal length of the relevant third support member.

[0027] The core layer may be enclosed within one or more reinforcing sheets.

[0028] The present invention also provides a method for forming structural honeycomb, wherein the method comprises connecting together a plurality of support members in a tessellating manner to form a plurality of hexagonal cells, wherein each of the support members is as described above.

[0029] The method may further comprise enclosing the plurality of support members within one or more reinforcing sheets. [0030] The present invention also provides a method for forming a support member for structural honeycomb, wherein the method comprises extruding a source material through a die to form the support member as described above.

[0031] The present invention also provides a method for forming a support member for structural honeycomb, wherein the method comprises pressing or moulding a source material to form the support member as described above.

[0032] The present invention also provides a method for forming a support member for structural honeycomb, wherein the method comprises bending an elongate member to form the support member as described above.

[0033] The present invention also provides a hexagonal pipe comprising a plurality of support members, wherein each of the support members has a cross-sectional shape that is partially hexagonal and the support members are connected together end-to-end to form the pipe.

[0034] At least one of the support members of the pipe may comprise:

a pair of elongate segments connected together end-to-end such that an angle of 120 degrees is formed between them; and

a pair of apertures formed, respectively, between the pair of elongate segments and at a peripheral end of the relevant support member, the apertures each being configured to receive an endmost portion of an adjacent support member of the pipe.

[0035] At least one of the support members of the pipe may comprise:

a single elongate segment; and

an aperture formed at a peripheral end of the single elongate segment configured to receive an endmost portion of an adjacent support member of the pipe.

[0036] According to the present invention, there is provided a support member for fabricating structural honeycomb, wherein the support member comprises:

at least five elongate segments connected together end-to-end in a zig-zag arrangement;

a pair of endmost portions, each of the endmost portions being elongate segments shorter than the five above elongate segments. [0037] The at least five elongate segments may be connected such that an angle of 120 degrees is formed between the first and second elongate segments and between the second and third elongate segments and between the third and fourth segments and between the fourth and fifth segments.

[0038] The shorter endmost elongate segments may be connected such that an angle of 120 degrees is formed between it and the first segment and at the other end between the short segment and the fifth elongate segment. The angle so formed is on the concave side of the respective zig-zag.

Brief Description of Drawings

[0039] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

Figure 1 (a) is a side view of a support member for fabricating structural honeycomb according to an example embodiment of the invention;

Figure 1(b) is an isometric view of the support member of Figure 1(a);

Figure 2(a) is a side view of an arrangement of three of the support members of Figure 1(a);

Figure 2(b) is a side view of the support members of Figure 2(a) connected together to form a hexagonal cell;

Figure 2(c) is a side view of a portion of structural honeycomb according to an example embodiment of the invention;

Figure 3(a) is a side view of an arrangement of four of the support members of Figure 1(a);

Figure 3(b) is a side view of the support members of Figure 3(a) connected together to form a hexagonal cell;

Figures 3(c) and 3(d) are side views of portions of structural honeycomb according to example embodiments of the invention;

Figure 4(a) is a side view of a support member for fabricating structural honeycomb according to an example embodiment of the invention;

Figure 4(b) is a side view of a support member for fabricating structural honeycomb according to an example embodiment of the invention;

Figure 5(a) is an isometric view of a support member for fabricating

structural honeycomb according to an example embodiment of the invention; Figure 5(b) is an isometric view of a support member for fabricating

structural honeycomb according to an example embodiment of the invention;

Figure 6(a) is a side view of a support member that may be comprised in structural honeycomb according to example embodiments of the invention;

Figure 6(b) is an isometric view of the support member of Figure 6(a);

Figure 6(c) is a side view of a support member that may be comprised in structural honeycomb according to example embodiments of the invention;

Figure 6(d) is an isometric view of the support member of Figure 6(c);

Figure 7(a) is a side view of a support member that may be comprised in structural honeycomb according to example embodiments of the invention;

Figure 7(b) is an isometric view of the support member of Figure 7(a);

Figure 7(c) is a side view of a support member that may be comprised in structural honeycomb according to example embodiments of the invention;

Figure 8 is a side view of a plurality of the support members of Figures 1(a), 6(a) and 7(a) arranged together in an unconnected configuration;

Figure 9 is a side view of a portion of structural honeycomb according to an example embodiment of the invention;

Figure 10(a) is a sectional isometric view of a portion of structural honeycomb according to an example embodiment of the invention;

Figure 10(b) is a side view of a portion of structural honeycomb according to an example embodiment of the invention;

Figure 11 is an isometric view of two layers of structural honeycomb according to the invention disposed in abutting contact; and

Figure 12 is an isometric view of a hexagonal pipe formed using three of the support members of Figures 6(a) and 6(b).

Figure 13 is a side view of an arrangement (131) of three support members, each comprising five elongate segments (80) joined at 120 degrees to form a zig-zag.

Endmost elongated segments (132) are of a shorter length, joined at 120 degrees, facing the concave side of the zig-zag. The three support members are arranged 120 degrees to each other forming a hexagonal core, with the two endmost members fastened by various means to the adjacent support member. Further iterations of the arrangement can be tessellated forming strong structural honeycomb. Description of Embodiments

[0040] Referring to Figures 1(a) and 1(b), an example embodiment of the present invention provides a support member 10 for fabricating structural honeycomb. The support member 10 comprises at least first, second and third elongate segments 12,14,16 connected together end-to-end in a zig-zag arrangement. The support member 10 further comprises first and second apertures 18,20 formed in the support member 10, respectively, between the first and second elongate segments 12,14 and between the second and third elongate segments 14,16. Each of the apertures 18,20 is configured to receive an endmost portion of an adjacent support member. The support member 10 further comprises a pair of endmost portions 22,24, wherein each of the endmost portions 22,24 is configured to fit into an aperture of an adjacent support member.

[0041] More particularly, the elongate segments 12,14,16 may be connected such that a concave angle of 120 degrees is formed between the first and second elongate segments 12,14 and between the second and third elongate segments 14,16. Each of the apertures 18,20 may be configured to receive an endmost portion of an adjacent support member, wherein the adjacent support member is substantially identical in shape to the support member 10. Further, each of the endmost portions 22,24 may be configured to fit into an aperture of an adjacent support member that is also substantially identical in shape to the support member 10.

[0042] Referring to Figure 1(b), in the example depicted the first of the apertures 18 may be disposed at the apex formed at the connection point between the first and second elongate segments 12,14. The second of the apertures 20 may be disposed at the trough formed at the connection point between the second and third elongate segments 14,16. The apertures 18,20 may be elongated and aligned such that their respective longitudinal axes 26,28 extend transversely between two side portions 30,32 of the support member 10 perpendicular to a longitudinal axis 34 of the support member 10.

[0043] The apertures 18,20 may comprise elongate channels 36,38 each having a cross- sectional shape that is substantially rectangular. The endmost portions 22,24 of the support member 10 may also be substantially rectangular. This provides that the elongate channels 36,38 are configured to receive endmost portions of an adjacent support member that is substantially identical in shape to the support member 10. The first and second elongate channels 36,38 are configured to receive the relevant endmost portions from, respectively, the underside and topside of the support member 10.

[0044] The elongate channels 36,38 may each be vertically aligned relative to the longitudinal axis 34 of the support member 10. This provides that the angle that is formed between the vertical axis of each elongate channel 36,38 and each of the elongate segments 12,14,16 adjacent to the relevant elongate channel 36,38 (i.e., each of the angles labelled a in Figure 1(a)) is 60 degrees.

[0045] The support member 10 is adapted for fabricating structural honeycomb comprising a plurality of hexagonal cells for use in building and construction. More particularly, pluralities of the support members 10 may be connected together to form individual tessellating hexagonal cells comprised in the honeycomb. For example, in Figure 2(a) there is shown three of the example support members 10 depicted in Figures 1(a) and 1(b) arranged such that the support members 10, in part, delineate a broken boundary of a single hexagonal cell 40. Each support member 10 forms, at least in part, two sides of the hexagonal cell 40.

[0046] Figure 2(b) shows the three support members 10 connected together to form a continuous unbroken boundary of the cell 40. An end portion 24 of each support member 10 slots into, and occupies, at least one elongate channel 36 of an adjacent support member 10. Each end portion 24 comprises an endmost part of the third elongate segment 16 of the relevant support member 10. Further, each end portion 24 spans the entire width of the relevant support member 10 between its side portions 30,32. The respective shapes and dimensions of the end portions 24 and elongate channels 36 of the support members 10 forming the cell 40 are complementary to one another. This provides that the whole of each end portion 24 slots into the receiving elongate channel 36 of the relevant adjacent support member 10 to achieve a secure interference fit.

[0047] It will be appreciated that when the support members 10 are connected together as depicted in Figure 2(b), the length of each of the six sides of the hexagonal cell 40 is equal to the length of the second elongate segment 14 of each support member 10 (i.e, the length labelled in the Figure). It will also be appreciated that the length of each side of the hexagonal cell 40 is equal to the length of the third elongate segment 16 of each support member 10, less the length of the endmost part of the elongate segment 16 that fits into an adjacent support member 10 (i.e, the length labelled in theFigure). [0048] As illustrated in Figure 2(c), additional support members 10 may be connected together in this manner to form a portion 42 of structural honeycomb comprising a plurality of tessellating hexagonal cells 40. While a total of 13 cells 40 are comprised in the example portion 42 that is depicted, additional support members 10 may be connected to form structural honeycomb of unbounded size and dimensions.

[0049] In another example, the plurality of tessellating hexagonal cells 40 shown in Figure 2(c) may form a core layer or portion comprised in a structural honeycomb material. The core layer may be enclosed within one or more reinforcing sheets (not shown) wrapped around one or more perimeter sections of the core layer. For example, a pair of parallel- aligned reinforcing sheets may be disposed at, respectively, topmost and bottommost perimeter sections of the core layer thereby sandwiching the core layer between the sheets.

[0050] Each reinforcing sheet may comprise a rigid or flexible film or planar member connected to the hexagonal cells 40 using a suitable connection means and adapted to strengthen and contain the hexagonal cells 40 within the core layer. The endmost portions 22,24 of each of the support members 10 that extend outwardly from the perimeter of the core layer may be connected to the reinforcing sheets using the connection means. The connection means may comprise adhesive, bolts or other fasteners. In other examples, a connection may be achieved using an interference fit between the endmost portions 22,24 and receiving apertures formed in the sheets or by using magnets.

[0051] In another example, in Figures 3(a) and 3(b) there is shown four of the support members 10 depicted in Figures 1(a) and 1(b) arranged together to form another single hexagonal cell 40. The two support members 10 labelled 44 in Figure 3(b) form, at least in part, two sides of the cell 40 and the two support members 10 labelled 46 each form, at least in part, just one side of the cell 40. As illustrated in Figures 3(c) and 3(d), additional support members 10 may be connected together in this manner to form portions 48,50 of structural honeycomb comprising a plurality of tessellating hexagonal cells 40. It will be appreciated that each of the honeycomb portions 48,50 may, taken as a whole, be duplicated one or more times and connected together in a tessellating manner to create larger portions of honeycomb.

[0052] Referring to the example honeycomb portions 42,48,50 depicted, each support member 10 forms at least part of an individual hexagonal cell 40 in the honeycomb and at least one other adjacent hexagonal cell 40. For example, in Figure 2(c) the support member 10 labelled 52 forms part of the hexagonal cell labelled 40.1 and also extends into, and forms part of, the adjacent hexagonal cell labelled 40.2. By way of further example, in Figure 3(c) the support member 10 labelled 54 forms part of the hexagonal cell labelled 40.2 and also extends into, and forms part of, the adjacent hexagonal cell labelled 40.1. This advantageously provides for a rigid and strong honeycomb structure that exploits the inherent rigidity of the material used to form the support members 10. Tension, compression and shear stresses are advantageously distributed equally across the hexagonal cells 40.

[0053] The individual hexagon cells 40 comprising the example honeycomb portions 42,48,50 are regular and each have substantially the same shape and size. This is because the elongate segments 12,14,16 of each support member 10 are connected such that an angle of 120 degrees is formed between the first and second elongate segments 12,14 and between the second and third elongate segments 14,16. Also, when each support member 10 is connected to an adjacent support member, the elongate segments 12,14,16 of the support member 10 have, effectively, the same length.

[0054] Honeycomb portions comprising irregular hexagon cells may be formed using the support member 10. For example, irregular cells may be achieved by modifying the relative lengths of the elongate segments 12,14,16 of the support members 10 and/or by modifying their arrangement such that the concave angle formed between the first and second 12,14 and the second and third 14,16 segments is less or more than 120 degrees.

[0055] Further modifications may be made to the support member 10 to form irregular honeycomb. For example, the elongate segments 12,14,16 of each support member 10 may be curved or have another non-linear shape. In other examples, the shape and dimensions of each support member 10 may be configured such that the respective diameters of the cells 40 vary across the honeycomb. For example, the support members 10 may be shaped such that the diameters of the cells 40 decrease (or increase) in a tapered manner towards one particular end of the honeycomb.

[0056] The support member 10 may be formed using a variety of different manufacturing processes. In one example, the individual elongate segments 12,14,16 that comprise the support member 10 may be integrally formed and continuous with one another. This, advantageously, enables the support member 10 to be mass produced using simple and cost effective manufacturing processes. For example, in this configuration the support member 10 may be formed by bending an elongate sheet of stiff, yet suitably pliable, source material such as a sheet of rolled steel, aluminium or similar metal. The bent sheet may then be folded in two places to form the elongate channels 36,38.

[0057] The support member 10 may be folded such that the channels 36,38 each protrude vertically from the support member 10 in one direction only. For example, in Figures 1(a) and 1(b) the first channel 36 is shown protruding vertically downwards relative to the longitudinal axis 34 of the support member 10 such that it occupies the concave area formed between the first and second elongate portions 12,14 and such that the aperture of the channel 36 faces the opposed convex area. The second channel 38 is shown protruding vertically upwards relative to the longitudinal axis 34 such that it occupies the concave section formed between the second and third elongate portions 14,16 and such that the aperture of the channel 38 faces the opposed convex area.

[0058] In another example, the channels 36,38 may protrude vertically in opposite directions to the ones shown in Figures 1(a) and 1(b) such that they are caused to occupy the respective convex sections formed between the first and second elongate portions 12,14 and the second and third elongate portions 14,16 and the apertures of the channels 36,38 face the opposed convex areas.

[0059] In another example, the support member 10 may be double folded at the two points of connection between the elongate segments 12,14,16. In this configuration, the channels 36,38 may each protrude vertically from the support member 10 in two opposed directions. For example, referring to Figure 4(a) the support member 10 depicted comprises first and second elongate channels 36,38 that each protrude both vertically upwards and downwards relative to the longitudinal axis 34 of the support member 10. The channels 36,38 protrude in each direction by substantially equal amounts. In this configuration, the effective depth of each channel 36,38 that receives an adjacent support member 10 is maintained whilst the extent to which the channels 36,38 protrude from the support member 10 is, advantageously, minimised.

[0060] If the source material used to make the support member 10 is not suitably pliable, it may not be practicable to form the support member 10 by bending and folding such material. Similarly, the required thickness of the support member 10 may be sufficiently large such that it is not possible to use such methods. Alternative manufacturing processes may, therefore, be used in such examples. For example, the support member 10 may be formed using a pressing process or by extruding a thermoplastic source material through a die. Using these methods, the support member 10 may, advantageously, be formed such that the elongate segments 12,14,16 comprising the support member 10 are integrally formed and continuous with one another. This provides for a strong and resilient support member 10 and also allows the support member 10 to be conveniently flat-packed during transit.

[0061] In other examples, a pressing or extrusion process may be used to form separate sections of the support member 10 that are then subsequently joined together using a suitable joining means.

[0062] Referring to Figure 4(b), there is shown the support member 10 according to a further example embodiment of the invention. The support member 10 is thicker than the examples illustrated in the preceding Figures and may be formed using a press or extrusion process. The sidewalls 58 of the elongate channels 36,38 of the support member 10 may be provided with buttresses 60 that are formed between the sidewalls 58 and the support member 10 to reinforce the side walls 58. The buttresses 60 may be tapered towards topmost ends of the sidewalls 58.

[0063] In another example, the support member 10 may further comprise a pair of bracket assemblies (not shown) wherein each bracket assembly comprises one of the elongate channels 36,38 of the support member 10. The bracket assemblies may be formed separately to the elongate members 12,14,16 and then attached to the elongate members 12,14,16 at their respective connection points using a suitable attachment means, such as rivets, screws, glue or weld points. The bracket assemblies may be particularly adapted for use with example support members 10 formed using press or extrusion processes and, advantageously, allow the elongate members 12,14,16 to be formed as one continuous piece using these processes before the bracket assemblies are attached.

[0064] In another example, the support member 10 maybe made using a relatively brittle material such as polypropylene, polyurethane, cement or a ceramic-based material. In another example, the support member 10 may be fabricated using a three-dimensional printer or a similar iterative manufacturing process. [0065] In another example, the apertures 18,20 of the support member 10 may comprise sockets (not shown) configured to receive complementary ball or dovetail type assemblies (not shown) attached to, or formed at, endmost portions 22,24 of an adjacent support member.

[0066] In another example, the support member 10 may be perforated with circular, hexagonal or other shaped apertures for reducing the weight and manufacturing cost of the support member 10.

[0067] Referring to Figure 5(a), there is shown the support member 10 according to a further example embodiment of the invention. The support member 10 is materially the same as the example depicted in Figure 4(b) save that it further comprises a metal apparatus 62 disposed proximal to each of the elongate channels 36,38 of the support member 10. Each metal apparatus 62 may be disposed towards a base end of the relevant channel 36,38 and, as depicted in the Figure, it may be embedded in the support member 10. Each metal apparatus 62 may comprise an elongate metal strip of iron aligned with the longitudinal lengths of the channels 36,38.

[0068] In the example depicted in Figure 5(a), the endmost portions 22,24 of the support member 10 may also each comprise one or more magnets 64. Each magnet 64 may be embedded in the support member 10 immediately underneath the peripheral surface of the relevant endmost portion 22,24. In the example depicted in Figure 5(a), the support member 10 comprises four magnets 64 that are disposed at, respectively, four corner sections of the support member 10.

[0069] In use, the metal apparatuses 62 and magnets 64 ensure that the endmost portions 22,24 of the support member 10 are held securely inside the elongate channels 36,38 of an adjacent support member when the support member 10 is used to construct a portion of structural honeycomb.

[0070] Referring to Figure 5(b), there is shown the support member 10 according to a further example embodiment of the invention. A first side portion 66 of the support member 10 comprises one or more protrusions 68 extending outwardly from the side portion 66. A second opposed side portion 70 of the support member 10 comprises one or more apertures (not shown) configured to receive protrusions 68 extending from a first side portion 66 of an adjacent support member when disposed in abutting contact with the support member 10. The protrusions 68 and apertures allow multiple layers of tessellating hexagon cells formed using the support member 10 to be layered on top of one another and held securely together.

[0071] The support member 10 may also be used in combination with other structural elements to form structural honeycomb. For example, referring to Figures 6(a) and 6(b) there is shown a further support member 80 comprising a pair of elongate segments 82,84 connected together end-to-end. The elongate segments 82,84 may be connected together such that an angle of 120 degrees is formed between them.

[0072] The support member 80 further comprises a pair of apertures 86,88. The first of the apertures 86 is formed in the support member 80 at the point of connection between the two elongate segments 82,84. The second of the apertures 88 is formed in the support member 80 at a peripheral end 90 of the support member 80. The apertures 86,88 are each configured to receive an endmost portion of an adjacent support member.

[0073] The apertures 86,88 may comprise elongate channels each having a cross- sectional shape that is substantially rectangular. These channels may be aligned such that their respective longitudinal axes extend transversely between two side portions 92,94 of the support member 80 and such that their respective vertical axes are perpendicular to the longitudinal axis of the support member 80.

[0074] The example support member 80 depicted in Figures 6(a) and 6(b) may be formed by bending a thin elongate sheet of pliable source material to form the pair of continuous elongate segments 82,84. The bent sheet may then be folded in two places to form the pair of apertures 86,88.

[0075] Referring to Figures 6(c) and 6(d), there is shown a further example of the support member 80. The elongate segments 82,84 of the support member 80 are thicker than those of the example shown in Figures 6(a) and 6(b) and may be formed by, for example, extruding a source material through a die. The sidewalls of the apertures 86,88 of the support member 80 may be provided with tapered buttresses 96 formed between the sidewalls and the support member 80 for reinforcing the side walls.

[0076] In other examples, the support member 80 may also comprise metal apparatuses 62 and magnets 64, as depicted in Figure 5(a), to facilitate attachment of the endmost portion of the support member 80 to an adjacent support member when used to construct structural honeycomb.

[0077] Referring to Figures 7(a) and 7(b) there is shown another support member 100. The support member 100 comprises a single elongate segment 102 with a single aperture 104 formed at a peripheral end 106 of the support member 100. The support member 100 is identical to the support member 80 depicted in Figures 6(a) and 6(b) save that the second elongate segment 84 and aperture 88 of the support member 80 is missing.

[0078] Figure 7(c) shows another example of the support member 100. The support member 100 is identical to the support member 80 depicted in Figure 6(c) save that the second elongate segment 84 and aperture 88 of the support member 80 is also missing.

[0079] In other examples, the support member 100 may also comprise metal apparatuses 62 and magnets 64, as depicted in Figure 5(a), to facilitate attachment of the endmost portion of the support member 100 to an adjacent support member when used to construct structural honeycomb.

[0080] The three types of example support members herein disclosed 10,80,100 may be connected together in various combinations to form structural honeycomb. For example, referring to Figure 8 there is shown a portion of structural honeycomb 110 that comprises a plurality of the support members 10,80,100 arranged together. For the sake of clarity, the support members 10,80, 100 are shown in the Figure in an unconnected arrangement.

[0081] More particularly, the honeycomb portion 110 comprises a total of two of the first type of support member 10, four of the second type of support member 80 and two of the third type of support member 100. The support members 10,80,100 may be connected together to form a strong and rigid honeycomb structure.

[0082] In another example, referring to Figure 9 there is shown a portion of structural honeycomb 112. The honeycomb portion 112 comprises a plurality of the example support members 10,80,100 depicted in Figures 4(b), 6(c) and 7(c) arranged together in a connected configuration. Figures 10(a) and 10(b) show similar examples of honeycomb portions 114,116 formed by connecting together the three types of example support members 10,80,100. [0083] Multiple layers of structural honeycomb formed using the support members 10,80, 100 may be layered on top of one another and joined together to form thicker instances of structural honeycomb. For example, referring to Figure 11 there is shown a pair of layers 118,120 of structural honeycomb layered on top of one another. Each layer 118,120 comprises a plurality of the example support members 10,80, 100 depicted in Figures 4(b), 6(c) and 7(c) arranged together in a connected configuration. The support members 10,80,100 in each layer 118, 120 may comprise the outwardly extending protrusions and complementary apertures that are provided with the example support member 10 depicted in Figure 5(b) to enable the two layers 118,120 to be fastened securely together.

[0084] Referring to Figure 12, there is shown a hexagonal pipe 130 in accordance with one further aspect of the invention. The pipe 130 comprises a plurality of support members, each having a cross-sectional shape that is partially hexagonal, connected together end-to-end to form the pipe 130. More particularly, the example pipe 130 that is depicted comprises three of the support members 80 shown in Figures 6(a) and 6(b) connected together in an end-to-end configuration.

[0085] In other examples, the pipe 130 may comprise six of the support members 100 shown in Figures 7(a) and 7(b) connected together end-to-end. In other examples, the pipe 130 may comprise a mixture of the support members 80,100 depicted in, respectively, Figures 6(a) and 6(b) and Figures 7(a) and 7(b) connected together end-to- end.

[0086] The pipe 130 may have a rigidity comparable to that of conventional circular pipes but, advantageously, uses significantly less material to manufacture. The pipe 130 is, therefore, lighter in weight and cheaper to manufacture and transport than conventional circular pipes.

[0087] Referring to Figure 13, there is shown an arrangement (131) of five support members 133, 134,135, 136, 137 joined in zig-zag fashion, each internal angle being 120 degrees. At either ends of the support structure is a shortened elongate support member (132) attached at an angle of 120 degrees relative to the concave face of the zig-zag. Three such arrangements can be configured as in Figure 2 to produce a hexagon cell structure that in itself can be tessellated to produce a plurality of hexagon cells of structural honeycomb. [0088] The support member 131 can be constructed, as an example, from a rod shaped material such as iron wire and bent into the shape of Figure 13 (131). Where the two end segments 132,133 and 137,132 overlap the middle segments 133,134 or 136,137 of the adjacent support member, the rods can be joined by strapping or other means at various locations along their length. Joining the two support members at a bend both fixes the alignment between the two and prevents them from rotating or pulling apart.

[0089] The descriptions and embodiments as shown above for Figure 2 and Figure 3 apply to the embodiments as shown in Figure 13. This arrangement is advantageous as it provides extra strength where the two end members overlap. Equally important it provides a simple means of aligning the support members to make a strong regular hexagon cell honeycomb structure without the need for other devices. Four such arrangements can also be configured to make hexagon cell structures similar to as shown in Figure 3. As an example, the material used to construct such support members can also be in sheet form, bent or moulded to the shape of 131 making tubular honeycomb when tessellated as in Figures 11 and 12. The central three support members 134,135,136 are equivalent to support members 12,14,16 in Figure 1 but without the apertures. The support members 132,133 and 137,132 effectively form the joining structure equivalent to an aperture as in Figure 1. The endmost members lock into the shape of the adjacent support members and when fastened, result in strong structural honeycomb. The various means of fastening are possible and are dependent on the material used. By way of example, strapping adjacent to each segment join or gluing and bolting.

[0090] Removal of three endmost elongate segments 132,133,134 from the embodiment 131 as shown in Figure 13 results in an equivalent support member as shown in Figure 6. Removal of elongate segments 132,133,134,135 from such embodiment results in an equivalent support member as shown in Figure 7. These reduced support members fill a similar role as shown in Figures 6, 7 and 8, completing hexagonal cells at the margins of the honeycomb structures so constructed, as shown in the example of Figure 8.

[0091] Embodiments of the present invention provide structural honeycomb useful for building and construction materials. Embodiments of the present invention also provide support members for forming structural honeycomb. [0092] For the purpose of this specification, the word“comprising” means“including but not limited to”, and the word "comprises" has a corresponding meaning.

[0093] The above embodiments have been described by way of example only and modifications are possible within the scope of the claims that follow.