AU2020301718A1

AU2020301718A1 - Structural member for a modular building

Info

Publication number: AU2020301718A1
Application number: AU2020301718A
Authority: AU
Inventors: Matthew Edward DINGLE
Original assignee: Formflow Pty Ltd
Current assignee: Formflow Pty Ltd
Priority date: 2019-06-26
Filing date: 2020-06-25
Publication date: 2022-01-20
Also published as: US20220259855A1; WO2020257856A1

Abstract

A structural member for a building, the structural member comprising: at least two spaced apart sidewalls, each sidewall formed from at least one contoured metal sheet; and at least one connecting vertex through which the sidewalls are connected, each connecting vertex include at least one structural bend formed in at least one of the contoured metal sheets, the sidewalls being connected through the connecting vertex to form a structural span therebetween, wherein each structural bend is formed between a first sheet section and a second sheet section of the respective contoured metal sheet, the first sheet section and second sheet section being connected about a bend line with the first sheet section extending from the bend line at a selected angle relative to the second sheet section, and wherein the first sheet section has a contoured profile that is a symmetrical mirror of the contoured profile to the second sheet section about the bend line.

Description

STRUCTURAL MEMBER FOR A MODULAR BUILDING

PRIORITY CROSS-REFERENCE

[001] The present application claims priority from Australian Provisional Patent Application No. 2019902227 filed at the Australian Patent Office on 26 June 2019, the contents of which should be understood to be incorporated into this specification by this reference.

TECHNICAL FIELD

[002] The present invention generally relates to a structural member for a building, particularly modular buildings such as a pre-fabricated modular building, and a building which includes that structural member. The invention is particularly appropriate for use with load-bearing structures, and in particular as a structural span within that load bearing structure. However, it should be appreciated that the invention is not limited to these applications and could be used in the construction of various building and structures.

BACKGROUND OF THE INVENTION

[003] The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.

[004] Corrugated iron was developed in the mid-nineteenth century to solve structural problems when large distances needed to be covered with minimal framing. The defining feature of the material is a number of corrugated or crimped grooves formed within flat sheets. These corrugations provide both a strengthening effect along with a distinctive image. In addition, the material is durable, lightweight, easy to maintain and affordable.

[005] Corrugated iron has been used to great effect in shipyards and railway yards and created a new industry for prefabricated demountable buildings by providing a cheap cladding material that could be attached to a load bearing framing structure. During World War I, corrugated iron was applied to temporary shelter designs for temporary military use, for example in a Nissen Hut (a semi-circular, prefabricated, corrugated iron barrack hut). In Nissen huts, corrugated iron sheets were often applied to a curved frame to increase the load bearing capacity. It was designed to be economical in the use of materials, portable and quick to erect.

[006] In all these applications, the structure is designed for the loads to be transferred through the internal framing to which the corrugated cladding is attached. In most cases, the structural contribution of the corrugated material to the load bearing capacity of the structure has been largely ignored. The function of corrugated iron and steel as a cladding material has therefore resulted in the development of thinner sheets made from high strength steel to maintain strength. However, the stiffness and therefore the load carrying capacity of the product have been compromised in this process.

[007] One problem with the use of corrugated sheets as a structural component in building structures is providing a structurally strong transition between a wall and roof section of a building. Wall and roof panels using corrugated sheets can be curved about an axis perpendicular to the corrugated profile and parallel to the plane of the sheet to provide structural strength, as was used in Nissen Huts. However, sharper transitions between these sections more typically require sharp bends to be included in the sheets. Such sharp bends can be difficult to be formed in a corrugated sheet in a way that would allow the structural loading to be transferred effectively.

[008] The Applicant has developed a solution to providing this type of sharp transition in corrugated metal (typically iron and steel) sheets, as taught in International Patent Publication No. WO2018/058183, the contents of which should be considered to be incorporated into the present specification by this reference. The general process produces a bend in a contoured metal sheet when a first sheet section of the metal sheet is bent about a bend line relative to a second sheet section of the metal sheet where the contoured profile of the first sheet section comprising a symmetrical mirror of the contoured profile of the second sheet section about the bend line. [009] The use of these bent corrugated sheets led to a number of unique cladding solutions in structures, for example when cladding the corners of buildings. However, the bent metal sheet was never previously considered for use in a structural application.

SUMMARY OF THE INVENTION

[010] The Applicant has surprisingly found that the bent corrugated metal sheets can be used in load bearing applications, structural spanning applications, and more particularly in load bearing and structural supporting applications in a building, in particular modular building construction.

[01 1] In one aspect of the present invention, there is provided a structural member for a building, the structural member comprising:

at least two spaced apart sidewalls, each sidewall formed from at least one contoured metal sheet; and

at least one connecting vertex through which the sidewalls are connected, each connecting vertex include at least one structural bend formed in at least one of the contoured metal sheets, the sidewalls being connected through the connecting vertex to form a structural span therebetween,

wherein each structural bend is formed between a first sheet section and a second sheet section of the respective contoured metal sheet, the first sheet section and second sheet section being connected about a bend line with the first sheet section extending from the bend line at a selected angle relative to the second sheet section,

and wherein the first sheet section has a contoured profile that is a symmetrical mirror of the contoured profile to the second sheet section about the bend line.

[012] The present invention solves the problem of transferring load effectively between wall and roof panels of a load bearing structure by utilising the material strength of a contoured metal sheet. In the present invention, load can be transferred through the outer skin/ cladding of the structure, via the contoured metal sheet of the structural member and through each structural bend at each vertex connecting the spaced apart sidewalls of the structure. This enables the outer cladding to be utilised as an important structural element, and thus providing an opportunity to reduce internal framing requirements of a building without compromising the load bearing capability of the overall structure. For example, buildings can be designed with less bracing and framing, reducing the weight and cost of the structure.

[013] The present invention also facilitates prefabrication of parts of a building, and modular building construction where structures can be fabricated away from the main structure and then assembled in situ due to the ability for components of the structure to be self-supporting. The prefabrication of simple modular elements are also facilitated.

[014] The structural bend in each vertex provides a structural corner transition capable of transferring load therethrough effectively. Each structural bend is formed as a sharp bend in the respective contoured metal sheet along a bend line where the contour of the first sheet section has a symmetrical mirror contoured profile to the second sheet section about the bend line. At this bend line, the contours run continuously on both sheet sections of the bent sheet and merge about the bend line making a neat join at the intersection of first sheet section and second sheet section. It should be appreciated that each structural bend can be formed using the process taught in the Applicant’s previous patent specification published in International Patent Publication No. WO2018/058183, the contents of which should be considered to be incorporated into the present specification by this reference. The resulting structural bend provides an alternate bend solution that is stiffer and stronger than a conventional metal sheet bent across and through the contours of the metal sheet In this case, the Applicant has surprisingly found that this structure is strong enough to provide load transfer capacity across and through that bend line between the first sheet section and the second sheet section, and therefore assist and maintain the load transfer and bearing properties of the overall contoured sheet material.

[015] The first sheet section is preferably orientated at a sharp angle bend relative to the second sheet section about that bend line. As outlined above, that sharp angle bend at the bend line can have any suitable bend radius. However, it is preferable that the bend radius is small enough to provide sharp change in angle at the bend line. In embodiments, the sharp angle bend has a bend radius of less than 5 mm, preferably less than 3 mm, more preferably about 2 mm. In other embodiments, the bend radius may be about zero, preferably zero. It should be appreciated that the minimum bend radius depends on the material, specifically on its "minimum bend radius" as defined in materials testing literature. The maximum radius is governed by the fact that over the radius the conditions for folding developable surfaces are not met geometrically and stretching or wrinkling become possible if the radius is too great. The sharp angle bend is preferably configured as a transverse bend i.e. the bend line is orientated 90 degrees to the longitudinal axis of the respective contoured metal sheet. It should be noted that bend line follows the junction between the first sheet section and second sheet section and therefore follows the contours between those sheets, and therefore can be a curved line where it follows those contours at this junction.

[016] As indicated above, each structural bend is formed between a first sheet section and a second sheet section of the respective contoured metal sheet, the first sheet section and second sheet section being connected about a bend line with the first sheet section extending from the bend line at a selected angle relative to the second sheet section. The strength in the bend structure results from the symmetrical profile of the contours across the bend line. Here, the first sheet section has a contoured profile that is a symmetrical mirror of the contoured profile to the second sheet section about the bend line. However, for some structures this may create an aesthetic disadvantage of the contours on the second sheet section not running concurrently with the contours on the first sheet section.

[017] The first sheet section can be angled about the bend line at a variety of angles relative to the second sheet section. In embodiments, the selected angle is between 5 and 175°, preferably between 10 and 150°, more preferably between 50 and 140°, and yet more preferably between 60 and 120°. In some embodiments, the selected angle is between 70 and 140°. In particular embodiments the selected angle is between 50 and 140°, preferably between 60 and 120°. In embodiments, the angle is 120°. In other embodiments, the selected angle is 90°. [018] It should be appreciated that whilst each vertex may include one structural bend, in a number of embodiments, one or more of the vertices may include two or more structural bends. Where an even number of structural bends are used, for example two, the contours of the first sheet section and second sheet section can be configured to match (and thus create an in-phase bend, where the contours of the sheets are able to run continuously through the structure it is mounted on) through the use of an intermediary sheet section which includes the different (symmetrical) contoured profile across the two bend lines.

[019] In such embodiments, at least one vertex is formed between a first sheet section, an intermediary sheet section and a second sheet section of at least one contoured metal sheet, the first sheet section and intermediary sheet section being connected about a first bend line with the first sheet section extending from the bend line at a first angle relative to the intermediary sheet section, the intermediary sheet section being connected about a second bend line with the second sheet section with the intermediary sheet section extending from the bend line at a second angle relative to the second sheet section, and wherein the first sheet section is positioned relative to the second sheet section at a selected angle comprising the sum of the first angle and the second angle. Here, the first sheet section has a contoured profile that is a symmetrical mirror of the contoured profile to the intermediary sheet section about the first bend line, the second sheet section has a contoured profile that is a symmetrical mirror of the contoured profile to the intermediary sheet section about the second bend line, and the contoured profile of the first sheet section is the same as the contoured profile of the second sheet section.

[020] The first and second sheet sections can be angled (i.e. bent) about the bend line to the intermediary sheet section at a variety of angles. However, cumulatively the sum of the first angle and the second angle are selected to form the required (or selected) corner angle for that particular vertex. In embodiments, the selected angle (the sum of the first angle and second angle) is between 5 and 175°, preferably between 10 and 150°, more preferably between 50 and 140°, and yet more preferably between 60 and 120°. In some embodiments, the selected angle is between 70 and 140°. In particular embodiments the desired angle is between 50 and 140°, preferably between 60 and 120°. In embodiments, the angle is 120°. In other embodiments, the selected angle is 90°. Whilst the first angle and second angle may be different, it is desirable for the vertex to have a symmetrical profile. Accordingly, the first angle and second angle are preferably the same angle, and thus comprise ½ of the selected angle of that vertex.

[021] In some embodiments, the first sheet section and second sheet section are bent at 45 degrees to the intermediary sheet section to form a 90 degree angle between the first sheet section and second sheet section. This forms an in-phase corner section between the first sheet section and second sheet section because the contours of these two sections are in-phase. Again, it should be appreciated that other in-phase angled corners can also be formed where the sum of the angle (angle 1 ) between the first sheet section and the intermediary sheet section and the angle (angle 2) between the second sheet section and the intermediary sheet section adds up to the required angle. For example, angle 1 plus angle 2 could equal any angle between 30 and 150 degrees, for example, 60 degrees, 100 degrees, 12 degrees or the like. Angle 1 and angle 2 may be the same angle or different angles.

[022] The bend line between the first sheet section and intermediary sheet section, and the bend line between the second sheet section and intermediary sheet section preferably forms a transverse bend, i.e. is orientated 90 degrees to the longitudinal axis of the metal sheet. It should be noted that bend line follows the junction between the first sheet section and intermediary sheet section, and the second sheet section and intermediary sheet section respectively and therefore follows the contours between those sheets, and therefore can be a curved line where it follows those contours at this junction.

[023] In the simplest form of the present invention, the structural member comprises two sidewalls joined at a single vertex comprising a structural bend formed in one or both of the contoured metal sheets. However, in most cases the structural member will include two or more vertices. In such embodiments, the sidewalls are connected about at least two vertices.

[024] In a number of embodiments, the sidewalls incorporate a roof structure formed between at least two, preferably at least three vertices. That roof structure can take any suitable form. For example, in embodiments the roof structure may comprises a flat roof structure; or a peaked roof structure. Where the roof structure comprises a peaked roof structure, that roof structure may have a vertex that includes at least one structural bend at the peak defining an angle between a first sheet section and a second sheet section of between 80 to 140°, preferably from 90 to 120°. In some embodiments, the angle is about 90°. In other embodiments the angle is 120°. Moreover, in embodiments where the sidewalls incorporate a roof structure formed between three of said vertices including at least one structural bend and the selected angle of the three structural bends respectfully comprising 135°, 90° and 135°. However, it should be appreciated that a variety of alternate roof structures are also possible, and that the selected angle of the structural bends at those vertices will differ depending on the exact configuration of the particular roof structure. For example, in some structures the selected angle of all three vertices is about 120^Q.

[025] The sidewall of the structural member can have any suitable configuration. In a number of embodiments, each sidewall includes at least one vertically standing section relative to a surface across which the structural member spans. However, various other configurations are possible, for example incorporating bends, recessed sections, stepped sections, curved sections, cut out sections or the like.

[026] The structural member can be comprised of two or more connected contoured metal sheets. In some embodiments, adjoining contoured metal sheets can be connected at locations proximate to or close to a vertex. However, the connections or joins between contoured metal sheets can be in any location along the length/perimeter of the structural member. Each contoured metal sheet is connected to an adjoining contoured metal sheet using a plurality of fasteners, preferably mechanical fasteners, such as roofing fasteners (rivets, screws, bolts etc.). In other embodiments, contoured metal sheet is connected to an adjoining contoured metal sheet using adhesive.

[027] The structural member can be formed from single spans of contoured metal sheets, or a composite structure which includes the contoured sheets and structural bends. In some embodiments, the structural member is comprised of two or more parallel spaced apart contoured sheets, arranged to form a composite structure. The composite structure can have any number of different forms. In some embodiments, the composite structure comprises two or more parallel spaced apart contoured sheets sandwiching a spacer structure. The spacer structure comprises at least one of: insulative material, shaped metal sheet element, or wood reinforcement element. In particular forms, the spacer structure comprises a repeating structure formed from a bent or angled metal sheet, for example a triangular spacer structure formed from a bent or angled metal sheet. In some forms, that metal sheet may comprise a contoured metal sheet.

[028] It is to be understood the contoured sheet or sheets comprising the structural member encompass any sheet having a contoured profile that extends perpendicular to the longitudinal axis of the sheet. Any number of contoured profiles could extend along the longitudinal axis of the sheet, including regular and irregular profiles and shapes, repeating and non-repeating profile shapes. In preferred embodiments, the contoured metal sheet encompasses any metal sheet having a contoured profile having a repeating cross-sectional shape that extends perpendicular to the longitudinal axis of the sheet. A large variety of repeating cross-sectional shapes are possible, such as curved, rectangular, triangular, square or the like. In a number of embodiments, the repeating cross-sectional shape comprises repeating peaks and troughs. The width of the peaks and troughs along a lateral centreline (spanning the cross-section) can be equal in the repeating pattern, or in other embodiments the width of the peaks and troughs along a lateral centreline can be different, resulting in the width of the peak being greater than or less than the width of the trough. In some embodiments, the repeating peaks and troughs form are curved, preferably forming a curved wave form. However, it should be appreciated that the peaks and troughs can comprise any number of different shapes. In exemplary embodiments, the metal sheet comprises a corrugated metal sheet.

[029] It should also be appreciated that metal sheet encompasses a wide variety of metal, metal alloys, and metal composites, including composite sheets fabricated from various layers of metals and non-metals, such as metal-polymer and/or metal- polymer-metal composites. In some embodiments, the metal sheet comprises at least one of an iron, steel, aluminium or copper metal sheet. The sheet may be coated, for example with paint or other similar film coating or another metal coating, such as a zinc coating (galvanized coating). In some embodiments, the metal sheet has a thickness of 0.1 to 3 mm, preferably 0.4 to 1.5 mm.

[030] As noted above, use of the structural member of the present invention provides an opportunity to reduce internal framing requirements of a building without compromising the load bearing capability of the overall structure. However, reinforcement such as internal framing may still be required to be attached to one or more sections of the structural member to provide the required load bearing and transfer requirements. Accordingly, in some embodiments the structural member further includes a reinforcement structure attached to the contoured metal sheets. That reinforcement structure may comprise at least one elongate member that extends between the sidewalls, preferably at least one elongate bracing member. In a number of embodiments, the reinforcement structure comprises a framework attached to the contoured metal sheets.

[031] A second aspect of the present invention provides a module element for constructing a modular building, the modular element including at least one structural member according to the first aspect of the present invention. The module element may further include at least one of: reinforcement structure; wall cladding, ceiling cladding; flooring panels, and flooring structure. In a further aspect, the present invention relates to a building that includes at least two interconnected module elements of this second aspect of the present invention.

[032] A third aspect of the present invention provides a building comprising at least two connected structural members according to the first aspect of the present invention. The building typically further comprises at least one of end walls, cross beams, windows, or door openings.

[033] The present invention thereby provides a simple construction method whereby a simple peaked roof structure can be prefabricated in sections lying flat on the ground (or workshop floor) and then assembled sequentially with final fixing completed without the need for standing on the roof. BRIEF DESCRIPTION OF THE DRAWINGS

[034] The present invention will now be described with reference to the figures of the accompanying drawings, which illustrate particular preferred embodiments of the present invention.

[035] Figure 1 provides a perspective view of a structural member according to a first embodiment of the present invention.

[036] Figure 2A and 2B illustrate a first form of a vertex of the structural member shown in Figure 1 , showing (2A) a 90 degree angle form; and (2B) a 135 degree angle form.

[037] Figure 3 illustrates a second form of a vertex of the structural member shown in Figure 1.

[038] Figure 4 shows a perspective view of an embodiment of a single module using the structural member shown in Figure 1 , in both (A) an exploded view; and (B) assembled view.

[039] Figures 5A to 5I illustrates a single module using the structural member shown in Figure 1 , illustrating a number of reinforcement and bracing elements that can be used in conjunction with the structural member, showing (5A) cross-section of the overall structure; (5B) a portion of a stringer illustrating the positioning of weld nuts thereon; (5C) a portion of a stringer showing the position of a brace; (5D) panel module formed of two sheets and a stringer; (5E) cross-sectional view showing a stringer and brace; (5F) roof joint; (5G) footing section; (5H) wall attachment to the footing section shown in 5H; and (5I) a section of a roof and wall joint.

[040] Figure 6 shows an exploded view of a series of modules incorporating the structural member shown in Figure 1 used in constructing a modular building.

[041] Figure 7 shows a plan view of a series of modules for constructing a modular building, as illustrated in Figure 5A to 5I. DETAILED DESCRIPTION

[042] The present invention utilises the material strength of a contoured metal sheet to create a structural element that transfers load through the contoured metal sheet (outer skin) of the structure. The structural member is able to create a span between two sidewalls by using a structural corner transition comprising a structural bend situated at each vertex connecting the spaced apart sidewalls of the structure. Load is transferred through the outer skin of the structure enabling it to be utilised as an important structural element. The structural loading of contoured metal sheets allows buildings to be designed with less bracing and framing, reducing the weight and cost of the structure.

Structural Member

[043] Figure 1 shows a first embodiment of a single structural member 100 of the present invention that can be used in constructing a modular building (for example as shown in Figures 4 to 6). The structural member 100 comprises two spaced apart sidewalls 1 10, each formed from a planar piece of contoured metal sheet. The sidewalls 1 10 are connected through a roof structure 1 12 to form a structural span 140 therebetween. As shown, each sidewall 110 comprises a vertically standing section relative to a surface across which the module spans. It is to be understood that vertically standing is defined as substantially perpendicular to a mounting surface or ground bearing surface. The mounting surface can include the ground and/or foundations.

[044] The roof structure 1 12 of the structural member 100 can have any suitable configuration, for example a flat roof structure; or a peaked roof structure. In the illustrated embodiment, the roof structure 1 12 comprises a peaked roof formed from two roof sheets 1 15A and 1 15B which extend from the sidewalls 1 10 (110A and 1 10B respectfully) at side vertices 120 at an angle of 120° and meet at a peak vertex 125 to define an angle of 120° between the two sheets. In other embodiments, the roof structure formed between three of said structural bends having selected angles of the three structural bends of 135°, 90° (peak roof apex angle) and 135°.

[045] The key to the structural loading capacity of this type of structural member is the configuration of these vertices 120 and 125. Each of the vertices comprises a structural bend (121 or 126) comprising a sharp angled bend that can be formed using a bending process as taught in International Patent Publication No. WO2018/058183. As previously discussed, the general process produces a bend in a contoured metal sheet when a first sheet section of the metal sheet is bent about a bend line relative to a second sheet section of the metal sheet where the contoured profile of the first sheet section comprising a symmetrical mirror of the contoured profile of the second sheet section about the bend line.

[046] In the illustrated embodiment, the structural bend 121 , 126 is formed at the end of a contoured metal sheet, and that sheet is attached to an adjoining sheet to form the desired peak roofed structure. In this respect, the required angle is formed at the ends of sheets 1 10A, 1 15B and 11 OB, and then the respective bent sheet of contoured metal sheet is attached to the respective adjoining piece of contoured metal sheet using mechanical fasteners (rivets, screws, bolts etc.) or an adhesive to create a length of contoured sheet having two planar sheets joined at bend line, and positioned at a selected angle to each other. As shown in Figure 1 , this has been used to create a join between the sidewalls 100 and roof structure 1 12 and at the peak vertex 125 of the roof structure 112.

[047] The structural bend 121 , 126 used at the vertices of the structural member 100 create a stiff brace/bracket structure on one or both ends of a continuous corrugated sheet. It enables the contoured metal sheet skin of a structure to be used as a continuous structural element in the structural member and a building into which the structural member is incorporated.

Contoured Metal Sheets

[048] Contoured metal sheets are well known in the art and are available (and can be formed) with a large variety of repeating cross-sectional shapes, such as curved, rectangular, triangular, square or the like. Figures 2A, 2B and 3 shows one form of contoured metal sheet that can be utilized in the present invention having a curved repeating cross-sectional shape comprises repeating peaks and troughs. The longitudinal axis direction is shown by lines L1 , L2 and L3. The metal sheet 100 can be formed from any suitable metal such as iron, steel, aluminium or copper metal sheet and may be coated (painted or zinc coated) in some forms. It should also be appreciated that the metal sheet encompasses a wide variety of metal, metal alloys, and metal composites, including composite sheets fabricated from various layers of metals and non-metals. Whilst it should be appreciated that different metals have different plastic deformation properties, which affect the bending and reforming properties of the metal sheet, the metal sheet used in the present invention typically has a thickness of 0.1 to 3 mm, preferably from 0.2 to 2 mm, and more preferably from 0.4 to 1.5 mm.

[049] Two configurations of vertex can be used in the structural member 100 shown in Figure 1.

[050] Figure 2A and 2B shows a first configuration of vertex 220 formed using a single structural bend between the two angled metal sheets (for example roof sheet 1 15 and sidewall sheet 1 10). The vertex 220 comprises a first sheet section 210 of a contoured metal sheet and a second sheet section 212 of a contoured metal sheet. Each of the first sheet section 210 and second sheet section 212 have a longitudinal axis L1 , L2 extending along the length of the respective sheet section 210, 212 and a curved contoured profile that extends perpendicular to the respective longitudinal axis L1 , L2. The first sheet section 210 and the second sheet section 212 are connected about transverse bend line F which is angled 90 degrees to the respective longitudinal axes L1 and L2. It should be noted that bend line F follows the junction between the first sheet section 210 and second sheet section 212 and therefore follows the curved contours between those sheets. The first sheet section 210 extends at a 90 degree angle (angle a in Figure 2A) relative to the second sheet section from the bend line F to form a right angle corner bend. Flowever, the uniqueness of this bend is that the repetitive contour of the first sheet section 210 has a symmetrical mirror contoured profile to the second sheet section 212 about the bend line F. As noted above, this allows the contours to run continuously on both sheet sections of the bent sheet and merge about the bend line F in a transitional contour thereby making a neat join at the intersection of the two sheet sections 210 and 212.

[051] As shown in Figure 2A, the first sheet section 210 is orientated at a sharp angle bend relative to the second sheet section 212 about that bend line. That sharp angle bend at the bend line typically has a bend radius of less than 5 mm, preferably around 2 mm. That bend produces a flat, in this case 45 degree fold surface 313 between the first sheet section 210 and second sheet section 212. The angle of that fold surface 313 corresponds to the angle of the fold plane.

[052] Furthermore, the first sheet section 210 can be angled about the bend line F at a variety of angles relative to the second sheet section 212. For example, Figure 2B illustrates a vertex 220A similar to the embodiment 220 described above in relation to Figure 2A except where the first sheet section 210A is angled at angle a = 120 degrees about the bend line F relative to the second sheet section 212A.

[053] Figure 3 shows a second configuration of vertex 320 formed using a two consecutive structural bends between the two angled metal sheets (for example roof sheet 1 15 and sidewall sheet 110) to form an in-phase right angled corner bend, i.e. where the contours of the sheets that extend away from the bend at 90 degrees have the same contoured pattern.

[054] The illustrated vertex 320 comprises a first sheet section 310 of contoured metal sheet, an intermediary sheet section 312 and a second sheet section 314 of contoured metal sheet. Each of the first sheet section 310, intermediary sheet section 312 and second sheet section 314 have a longitudinal axis L1 , L2, L3 (Figure 3) extending along the length of the respective sheet section 310, 312, 314 and a curved contoured profile that extends perpendicular to the respective longitudinal axis L1 , L2, L3. The first sheet section 310 and the intermediary sheet section 312 are connected about transverse bend line F1 which is angled 45 degrees to the respective longitudinal axes L1 and L2. It should be noted that bend line follows the junction between the first sheet section 310 and intermediary sheet section 312 and follows the contours between those sheets, and is therefore a curved line where it follows those contours at this junction. The first sheet section 310 extends at a 45 degree angle (angle g in Figure 3) relative to the intermediary sheet section 312 from the bend line F1. Similarly, second sheet section 314 and the intermediary sheet section 312 are connected about transverse bend line F2 which is angled 45 degrees to the respective longitudinal axes L3 and L2. The second sheet section 314 extends at a 45 degree angle (angle h in Figure 3) relative to the intermediary sheet section 312 from the bend line F2. Like the previous embodiment, the uniqueness of each bend is that the repetitive contour of the first sheet section 310 or second sheet section 314 has a symmetrical mirror contoured profile to the intermediary sheet section 312 about the bend line F1 or F2. As shown, the intermediary sheet section comprises a short segment of sheet, providing a transitory segment between the two 45 degree bends relative to the first sheet section 310 or second sheet section 314. This vertex 320 therefore forms a 90 degree angle through the sum of the two 45 degree bends. Unlike the first vertex configuration, the contours of the first sheet section 310 or second sheet section 314 are in phase, having the same repetitive contour.

[055] Whilst not illustrated, a variation of the second vertex configuration is where the in-phase corner vertex 320 is formed from two overlapping 45 degree bent contoured metal sheet elements 301. Flere, two 45 degree bends are formed at the end of two separate contoured metal sheets, and the shorter end sections (intermediary sheet sections 312) of each of metal sheet element are overlapped to from a 90 degree corner element having a similar configuration as the vertex 320 shown in Figure 3.

Reinforcement Structure

[056] Figure 4 illustrates a module 400 that can be used to construct a prefabricated building (not illustrated) that uses a structural member 100 illustrated in Figure 1 .

[057] As shown in Figures 1 and 4, the structural member 100 is created using four contoured metal sheets 1 10A, 110B, 1 15A and 1 15B which are attached at adjoining ends to form the overall spanning structure. In the illustrated embodiments, each of the sidewall sheets 1 10A and 115A include a 135^Q structural bend 121 at the non ground engaging end, and one of the roof sheets 1 15B includes a 90^Q structural bend 126 at the peak forming end thereof. The remaining roofing sheet 115A comprises a planar contoured metal sheet. The structure is preferably created by assembling these sheets to an adjoining sheet on the ground to form the desired peak roofed structure. This provides the advantage that the connections can be made without needing a ladder or some other device to work at a given height off the ground. The respective bent sheet of contoured metal sheet is attached to the respective adjoining piece of contoured metal sheet using mechanical fasteners (rivets, screws, bolts etc.) or an adhesive to create a length of contoured sheet having two planar sheets joined at bend line and positioned at a selected angle to each other.

[058] The module 400 is completed by attaching the structural member to a flooring structure 410, adding a reinforcing framework 420 and internal wall and ceiling cladding/panels 430.

[059] As shown in Figure 4, the floor structure 410 may comprise a flooring panel 412 which spans between two spaced apart floor beams 414. However, other floor structures are possible, as are well known in the building and construction art. For example as shown in Figure 5(A) and 5(G), which comprises a floor footing beam 438 which is attached to a ground engaging concrete footing 450.

[060] Minimal internal framing is typically required to ensure the structural integrity of the completed structure. As shown in Figures 4 and 5A, the module 400 includes a series of stringers 422 which extend laterally along the sidewall panels 1 10 and are used to mount wall cladding panels 432 thereon. Roof beams and roof braces 423 and 425 can also be used to provide additional cross-bracing to the roof structure and provide a mounting surface for internal ceiling panels 434.

[061] Figures 5A to 5I provide further detail of the framing and reinforcement configurations that can be used within the structural member 100 of the present invention. As shown in the various figures, the reinforcement structure largely comprises elongate metal members which are mechanically fastened to the sidewall 1 10 or roof sheets 1 15. The illustrated framing (stringers 422, and roof beams and roof braces 423 and 425 with wall and ceiling panels) is attached to the contoured metal sheets 110, 115 using mechanical fasteners. The roofing reinforcement comprises a framework consisting of sidewall stringers 422 connected to sidewall panels 1 10 using mechanical fasteners, and similarly roof stringers 427 connected to the roof panels 1 15 using mechanical fasteners. Cross-braces 424 and 425 are then attached from the sidewall stringers 422 to the roof stringers 427 and between the roof stringers 427 to provide a modicum of cross-bracing between the sidewalls and roof structure. [062] Once a modular segment 400 has been pre-assembled (for example on the ground) it can be lifted up and positioned alongside another modular segment. As shown in Figure 5D, each modular segment 400 will overlap by approximately 1.5 corrugations and the framing sections will also overlap. To complete the overall structure only the framing sections and the wall to floor connections need to be made. This eliminates the need to work at elevated heights and opens up many new applications for corrugated sheeting that combine the aesthetic and structural benefits of corrugated sheeting.

[063] Each wall section is fixed to the ground by attaching the bottom (ground facing or engaging) edge of each sidewall panel 1 10 to a floor structure 410 (Figure 4) or other flooring structural section, for example footing beam 438 (Figure 5A and 5G) using mechanical fasteners, welding or adhesive bonding. Any flooring structural section, such as footing beam 438 can be fixed to the concrete slab or footing 450 using mechanical fasteners, for example as shown in Figure 5A.

[064] A modular building structure 500 can therefore be constructed using two or more of the structural members 100, and a corresponding reinforcing and cladding structure. An example is illustrated in Figures 6 and 7, which shows a plurality of structural members 100 which can be used to link a module 510 which also includes structural members 100 and reinforcing and cladding elements (as previously described). Further elements 520 and 530 are also included in the assembly which provide window and door elements, and end capping seals to enable the building to be assembled from the modular elements.

[065] The modules and associated elements of the building structure 500 can be assembled in an orientation that is convenient for the assembly process and then assembled in the final location or at some intermediate stage to form a complete building. Again, the overall structure of this modular building 500 is designed to allow load to be transferred through the outer skin of the structure enabling it to be utilised as an important structural element.

[066] It should be appreciated that in some embodiments the structural members 600 could be formed from composite sheet materials comprising two parallel spaced apart sheets interconnected by a spacer material. For example, in Figure 8 the structural members 600 can be formed from a composite sheet 605 comprising two spaced apart contoured sheets 610 and 612, having a triangular spacer 615 adhered or otherwise fixed between the sheets to form a laminated or composite sheet. This composite sheet 605 includes vertices 620 similar to the previously described vertices which form structural bends used to form the corner structures in the structural members as previously described.

[067] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.

[068] Where the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other feature, integer, step, component or group thereof.

Claims

1. A structural member for a building, the structural member comprising:

2. A structural member according to claim 2, wherein at least one vertex includes at least two structural bends.

3. A structural member according to claim 1 or 2, wherein the at least one vertex is formed between a first sheet section, an intermediary sheet section and a second sheet section of at least one contoured metal sheet, the first sheet section and intermediary sheet section being connected about a first bend line with the first sheet section extending from the bend line at a first angle relative to the intermediary sheet section, the intermediary sheet section being connected about a second bend line with the second sheet section with the intermediary sheet section extending from the bend line at a second angle relative to the second sheet section, and wherein the first sheet section is positioned relative to the second sheet section at a selected angle comprising the sum of the first angle and the second angle,

and wherein the first sheet section has a contoured profile that is a symmetrical mirror of the contoured profile to the intermediary sheet section about the first bend line, the second sheet section has a contoured profile that is a symmetrical mirror of the contoured profile to the intermediary sheet section about the second bend line, and the contoured profile of the first sheet section is the same as the contoured profile of the second sheet section.

4. A structural member according to any one preceding claim, wherein the selected angle between the first sheet section and the second sheet section of each structural bend is between 5 and 175°, preferably between 10 and 150°, and more preferably between 60 and 120°.

5. A structural member according to any preceding claim, wherein the sidewalls are connected about at least two vertices.

6. A structural member according to any preceding claim, wherein the sidewalls incorporate a roof structure formed between at least two, preferably at least three vertices.

7. A structural member according to claim 6, wherein the roof structure comprises at least one of: a flat roof structure; or a peaked roof structure.

8. A structural member according to claim 6 or 7, wherein the roof structure comprises a peaked roof structure having a vertex that includes at least one structural bend at the peak defining an angle between a first sheet section and a second sheet section of between 80 to 140°, preferably from about 90° to about 120°.

9. A structural member according to any preceding claim, wherein the sidewalls incorporate a roof structure formed between three of said vertices including at least one structural bend and the selected angle of the three structural bends respectfully comprising 135°, 90° and 135°.

10. A structural member according to any preceding claim, wherein each sidewall includes at least one vertically standing section relative to a surface across which the structural member spans.

1 1. A structural member according to any preceding claim, wherein the bend line is orientated 90 degrees to the longitudinal axis of the respective contoured metal sheet.

12. A structural member according to any preceding claim, wherein each structural bend has a bend radius at the respective bend line of less than 5 mm, preferably less than 3 mm.

13. A structural member according to any preceding claim, wherein the structural member is comprised of two or more connected contoured metal sheets.

14. A structural member according to any preceding claim, wherein the structural member is comprised of two or more parallel spaced apart contoured sheets, arranged to form a composite structure.

15. A structural member according to claim 14, wherein the composite structure comprises two or more parallel spaced apart contoured sheets sandwiching a spacer structure.

16. A structural member according to claim 14, wherein spacer structure comprises at least one of: insulative material, shaped metal sheet element, or wood reinforcement element.

17. A structural member according to any preceding claim, wherein each contoured metal sheet is connected to an adjoining contoured metal sheet using a plurality of fasteners, preferably roofing fasteners.

18. A structural member according to any preceding claim, wherein the contoured profile of each metal sheet comprises a repeating cross-sectional shape that comprises repeating peaks and troughs.

19. A structural member according to claim 18, wherein the repeating peaks and troughs form a curved wave form.

20. A structural member according to any preceding claim, wherein each contoured metal sheet comprises a corrugated metal sheet.

21. A structural member according to any preceding claim, wherein the metal sheet comprises at least one of a metal, metal alloy, or metal composite, preferably comprising at least one of an iron, steel, aluminium or copper metal sheet.

22. A structural member according to any preceding claim, wherein the metal sheet has a thickness of 0.1 to 3 mm, preferably 0.4 to 1.5 mm.

23. A structural member according to any preceding claim, further including a reinforcement structure attached to the contoured metal sheets.

24. A structural member according to claim 23, wherein the reinforcement structure comprises at least one elongate member that extends between the sidewalls, preferably at least one elongate bracing member.

25. A structural member according to claim 23 or 24, wherein the reinforcement structure comprises a framework attached to the contoured metal sheets.

26. A module element for constructing a modular building, the modular element including at least one structural member according to any one of the preceding claims.

27. A module element according to claim 26 further including at least one of: reinforcement structure; wall cladding, ceiling cladding, flooring panels, and flooring structure.

28. A building comprising at least two connected structural members according to any one of the preceding claims.

29. A building comprising at least two connected module elements according to claim 26 or 27.

30. A building according any one of claims 28 or 29, further comprising at least one of end walls, cross-beams, windows, or door openings.