GB2599922A

GB2599922A - Cross-car beam for a vehicle

Info

Publication number: GB2599922A
Application number: GB2016279.8A
Authority: GB
Inventors: Desai Shanta
Original assignee: Nissan Motor Manufacturing UK Ltd
Current assignee: Nissan Motor Manufacturing UK Ltd
Priority date: 2020-10-14
Filing date: 2020-10-14
Publication date: 2022-04-20
Also published as: GB202016279D0

Abstract

A cross-car beam 22 of a vehicle has a tubular beam body 30 of a composite material, typically reinforced with glass or carbon fibre, and extends in a length direction from a first end 30a to a second end 30b. Body 30 has a first region 32 extending a first distance lengthwise along beam body 30 and at least one mounting feature (48, Figure 3) to which a mounting collar (24, Figure 1) is attachable. The mounting feature is defined by a second region 34 which extends a second distance lengthwise along beam body 30 and which is narrower than first region 32 in a direction transverse to the length direction. The cross-section of body 30 may be typically be circular or square, and may be constant within first region 32, while second region 34 may have a smaller diameter than first region 32.

Description

CROSS-CAR BEAM FOR A VEHICLE

Technical Field

The invention relates to the field of vehicle cross-car beams.

Background of the Invention

Cross-car beams are important structural components of motor vehicles. Positioned at the front of the vehicle cabin and transverse to the main structure of the vehicle, the cross-car beam has important roles in both the stability and safety of the vehicle. Cross-car beams are generally attached to the A-pillars of the vehicle.

The cross-car beam provides additional lateral stiffness to the vehicle which assists with vehicle handling. It is also designed to help prevent compression of the sides of the vehicle when in a side-on collision. Further to these design considerations, the cross-car beam also serves as the part of the vehicle structure to which many other important internal components are attached. These include the steering column, the instrument panel/dashboard and both the driver-side and passenger-side airbags. The cross-car beam accordingly acts as the load path that transfers the weight of the steering column to the vehicle body Given the functions of the cross-car beam, it is imperative that the component itself has strong mechanical properties. The cross-car beam must be strong and tough to resist collisions, whilst also being stiff enough to fulfil its role in improving the lateral stiffness of the vehicle.

For these reasons, steel is the most common material used in cross-car beams for vehicles today. Steel also has the benefit of being comparatively cheap, with well-established processing routes existing for steel components. This allows satisfactory components to be made quickly and cost effectively, which is of great benefit to vehicle manufacturers.

However, one disadvantage of the use of steel in cross-car beams is the fact that steel cross-car beams are heavy and add significantly to the weight of the vehicle. This can have negative consequences for vehicle emissions, with heavier vehicles consuming more fuel than comparable vehicles that weigh less. Given the current focus on improving the energy efficiency of vehicles, finding a way to reduce the weight of cross-car beams would be desirable.

It is an object of the invention to provide a cross-car beam that avoids or at least mitigates some of the problems explained above.

Summary of the Invention

Against this background, the invention provides in a first aspect a cross-car beam of a vehicle.

The cross-car beam comprises a tubular beam body of a composite material extending in a length direction from a first end to a second end. The body includes at least one first region that extends a first distance along the beam body in the length direction, and at least one mounting feature to which a respective mounting collar is attachable, wherein the mounting feature is defined by a second region that extends a second distance along the length direction of the beam body. The second region is narrower than the first region in a dimension transverse to the length direction.

The first region of the tubular beam body may have a constant cross-sectional area and may be of a braided fibre-reinforced composite construction. The tubular beam body may extend along a longitudinal axis and be rotationally symmetric about said axis. The tubular beam body may also be symmetric about a plane normal to the longitudinal axis.

The first region may be one of a plurality of relatively wide first regions and the second region may be one of a plurality of relatively narrow second regions.

The tubular beam body may surround a solid core.

The invention also relates to a cross-car beam assembly that comprises the cross-car beam described above and at least one mounting collar, each mounting collar being configured to engage with a respective one of the at least one mounting features.

The at least one mounting collar and each respective second region may be configured such that, when the mounting collar is received into the respective second region, an outer surface of the mounting collar is substantially flush with an adjacent outer surface of the first region. The at least one mounting collar may be metallic.

The cross-car beam assembly may further comprise a first end cap engaged with the first end of the tubular beam body and/or a second end cap engaged with the second end of the tubular beam body. The first end cap and/or second end cap may be metallic.

The cross-car beam assembly may further comprise a mounting stanchion fixed to the respective one or more mounting collars.

In another aspect, the invention relates to a method of making a cross-car beam assembly for a vehicle. The method comprises: providing an elongate former member having a first end and a second end and defining a major axis, the former member including at least one first region extending a first distance and at least one second region extending a second distance, wherein the second region is narrow in a direction transverse to the major axis compared to the first region; applying composite fabric material to the former such that an un-cured tubular body made of fabric is built up on the former to take the shape thereof; applying an uncured resin material to the uncured tubular body; and curing the un-cured tubular body to form a cured composite tubular body.

The former member may be a solid body or may be an inflatable body. In the case where the former member is an inflatable body, the method may include deflating the former member following the curing step and removing the former member from the interior of the cured body.

The method may further comprise applying a first end cap to the tubular body and/or applying a second end cap to the tubular body. The first and/or second end cap may be applied to the tubular body before it is cured. The first and/or second end cap may also be applied to the tubular body after it is cured.

The method further comprises applying a mounting collar to respective ones of the relatively narrow second regions. A bonding agent may subsequently be applied to faying surfaces of the at least one mounting collar and the respective second region. A mounting stanchion may then be fixed to respective ones of the mounting collars.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

Brief Description of the Drawings

In order that it may more readily be understood, the invention will now be described, by way of example only, with reference to the following drawings in which: Figure 1 shows a perspective view of a cross-car beam assembly connected to a vehicle; Figure 2 is a schematic side view of a cross-car beam of the cross-car beam assembly of Figure 1; Figure 3 is a perspective view of one end of the cross-car beam of Figure 2 showing mounting features and a mounting collar; Figure 4 is a cross-sectional view of the cross-car beam and mounting collar of Figure 3, taken along the plane P2; and Figures 5a to 5d show steps of a method of manufacturing the cross-car beam of the above figures

Detailed Description of the Embodiments

Figure 1 shows in schematic form a body 10 of a vehicle including a cross-car beam (CCB) assembly 20. It will be appreciated at this point that the vehicle body 10 is not shown fully here, but its presence is implied. The CCB assembly 20 comprises a CCB 22 positioned transversely across a front end of the body 10 and attaches to the rest of the body 10 at or near the A-pillars (not shown), in front of the passenger cabin. As can be seen in Figure 1, a number of mounting collars 24 are mounted on the CCB 22, with a mounting stanchion 26 fixed to each of the respective mounting collars 24. It will be understood by the skilled person that various components of the vehicle, such as a steering column or instrument panel, may be mounted to the mounting stanchions 26, although these details are not shown in the drawings for the sake of clarity. The individual components of the CCB assembly 20 are discussed in further detail below, starting with the CCB 22.

Figure 2 shows the CCB 22 in greater detail, again in schematic form. In Figure 2, the CCB comprises a linear beam body 30 that is tubular in form and extends from a first end 30a to a second end 30b along a longitudinal axis L, in this example. The longitudinal axis L defines a length direction. The CCB 22 is rotationally symmetric about the longitudinal axis L such that the CCB 22 has a substantially circular cross-section along the length direction. The CCB 22 is also symmetric about a plane P1 normal to the longitudinal axis L in this example.

It will be appreciated that other configurations of the CCB 22 are envisaged. The CCB 22 may be formed such that bends exist within the beam body 30, as opposed to the linear form shown in Figure 2. In this configuration, the CCB 22 may take a yoke-like shape. Additionally, although the illustrated cross-section of the beam body 30 is circular, this is not essential and other configurations such as, for example, substantially square or rectangular sections are possible.

As can also be seen in Figure 2, the beam body 30 includes a plurality of first regions 32 and second regions 34. The second regions 34 are narrower than the first regions 32 with respect to a dimension transverse to the longitudinal axis L, such that the cross-sections defined by the second region 34 are smaller than those defined by the first region 32. In the illustrated example, the second regions 34 have a smaller diameter than the first regions 32. Although Figure 2 shows the first regions 32 and second regions 34 having cross-sections of the same shape, it would be possible for the cross-sections of the two regions 32, 34 to differ. For example, the first regions 32 may have a substantially circular cross-section, while the second regions 34 may have a substantially box-shaped cross-section.

It should also be understood that the second regions need not have a constant cross section along their entire length. The second regions 34 may include additional 'keying features' (not shown in any of the figures) such as protrusions and recesses that give the second regions an appearance similar to that of a key. The general principle, however, is that the second regions 34 are narrower than the first regions 32 in such a way as to define mounting features 48, as will be described later.

The beam body 30 is formed of a braided fibre reinforced composite material. The fibres may be made of any suitable material, such as glass, Kevlar (RTM) or carbon, while the surrounding matrix can be made from any typical resin used in composite material manufacture. Through use of a composite material, the CCB 22 can maintain comparable mechanical properties, such as high strength and toughness, to steel GCBs, while also benefitfing from a significant reduction in weight. Despite the reduction in weight, the CCB 22 of the invention can therefore still fulfil its function of preventing compression of the sides of the vehicle in collisions. Additionally, composite materials are widely regarded for their high stiffness, which is also beneficial for the role of the CCB 22 in providing lateral stiffness to the vehicle Figure 2 also shows shoulder regions 36 that separate the first regions 34 from the second regions 32 and span the difference in cross-section between the two regions. The shoulder regions 36 are inclined to the longitudinal axis L in this example, The inclined shoulder regions 36 are not essential to the function of the CCB 22 but, in comparison to a CCB configuration in which the shoulder regions 36 are vertical, help to avoid stress concentrations in the fibres of the composite that occur where the cross-section of the beam body 30 changes suddenly. This helps reduce the presence of preferred fracture paths within the fibres, which would may compromise the strength of the CCB.

In addition to the CCB 22, Figure 2 also shows two metallic end caps 40, with one end cap 40 being inserted into each of the first and second ends 30a, 30b of the beam body 30. The end caps 40 comprise a cap section 42, which is discoidal in form. The large surface area of the cap section 42 provides a solid base to which conventional side brackets 44 (seen best in Figure 1) may be attached in order to affix the CCB assembly 20 to the body 10 of the vehicle.

Through using conventional side brackets 44, existing manufacturing and assembly methods for attaching the side brackets 44 to the body 10 of the vehicle may be utilised, minimising disruption in the production and assembly chain.

The end caps 40 each additionally comprise a plug section 46 that extends from a first face 42a of the cap section 42. Each plug section 46 has a cross-section that is substantially equal to an internal cross-section of a respective socket 47 defined at the first and second ends 30a, 30b of the CCB 22 such that the plug sections 46 fit tightly within the ends 30a, 30b of the CCB 22, in use. In the embodiment shown in Figure 2, each plug section 46 is substantially cylindrical such that they fit tightly within the substantially circular cross-section of the socket 47 defined in the beam body 30. The plug sections 46 may each comprise a thread running therearound that engages with a corresponding thread in each respective socket 47 in order to secure the end caps 40 in place. Alternatively, or additionally, an adhesive may be applied to the plug sections 46 to fix the end caps 40 in place within the CCB 22.

The end caps 40 provide a means for a transition from composite material to metal, allowing the CCB assembly 20 to be fixed to the body 10 of the vehicle without the structural integrity of the final vehicular structure being compromised. This transition to metal also allows for conventional fixation methods to be applied in fixing the CCB assembly 20 to the side brackets 44.

Figure 3 shows the attachment of the mounting collars 24 to the CCB 22 in greater detail. Each mounting collar 24 is metallic in nature and is attached to the CCB 22 at one of the plurality of second regions 34 along its length. In the embodiment shown in Figure 3, each mounting collar 24 comprises two parts 24a, 24b which complement one another so as to wrap around the CCB 22 and grip the relatively narrow second region 34. In this example, each part 24a, 24b is generally C-shaped in form. As such, each part 24a, 24b comprises a channel section 50 and a flange 52 at each lip of the channel sections 50. In the embodiment shown in Figure 3, the channel sections 50 are substantially semi-circular. As shown in Figure 3, the two parts 24a, 24b of the mounting collar 24 cooperate to clamp around the associated second region 34 of the CCB 22 in an opposed relation. As such, the second region 34 defines a mounting feature 48 for the respective mounting collar 24. The two parts 24a, 24b of the mounting collars 24 are joined and fixed together by pins 54 running through each respective pair of flanges, as shown in Figure 4. The internal cross-section of the mounting collar 24 formed by the joining of the two parts 24a, 24b substantially matches the external cross-section of the second regions 34 of the CCB 22 such that joining the two parts 24a, 24b of the mounting collars 24 together around the mounting features 48 fixes the mounting collars 24 in place.

The skilled person would appreciate that the flanges 52 could be affixed by means other than pins. For example, they could be welded or bonded by suitable techniques. It is also envisaged that an adhesive may be applied to the inner surface of each mounting collar 24 to secure them to the CCB 22. Such a measure may improve the resistance of the collar to lateral movement under high side impact forces. Application of an adhesive can also improve the resistance of the metal mounting collar 24 to galvanic corrosion through contact with the CCB 22. It should be appreciated that the mounting collars 24 may be affixed to the CCB 22 through the use of more than one of the fixing mechanisms described above. For example, an adhesive may be applied between the mounting collars 24 and the CCB 22 in addition to pins 54 running through the flanges 52 of the CCB 22.

It will be apparent to the skilled person that the mounting collar 24 may be configured in other ways to that shown in Figures 3 and 4. For example, the mounting collar 24 may take a clamshell configuration, with a hinge that can open and close to allow the mounting collar 24 to be attached to the mounting features 48. In this case, the mounting collars 24 may also comprise a single pair of flanges 52 that oppose each other when the mounting collar 24 is closed around the CCB 22 and that are fixed together by pins 54, in a similar way to the two-part mounting collar 24 shown in Figures 3 and 4.

Notably, the difference in cross section between the first and second regions 32, 34 provides a means to keep the mounting collars 24 in place at the correct location along the CCB 22, as the internal cross section of the mounting collars 24 is too small for the mounting collars 24 to be able to move away from the second region 34 and along the CCB 22 in the length direction.

As well as the internal cross-section of the mounting collar 24 being substantially equal to the external cross-section of the second regions 34, the external cross-section of the mounting collar 24 is substantially equal to the external cross-section of the first regions 32. Therefore, when the mounting collars 24 are attached to the CCB 22, the cross-car beam assembly 20 has a substantially constant cross-section, with outer surfaces of the mounting collars 24 lying substantially flush with adjacent outer surfaces of the first regions 32. It should be appreciated that if the mounting collars 24 comprise flanges 52, these do not lie flush with the outer surfaces of the first regions 32. Rather, it is the channel sections 50 of the mounting collars 24 that lie flush with the first regions 32. This allows the cross-car beam assembly 20 of the present invention to fit with existing vehicle designs that were based around conventional cross-car beam assemblies.

Referring back to Figure 1, the mounting stanchions 26 are shown to be fixed to the mounting collars 24 and are provided so that various components of the vehicle, such as the instrument panel and steering column can be attached to the cross-car beam assembly 20 during assembly of the vehicle. The mounting stanchions 26 are fixed to the mounting collars 24 by conventional means, such as spot welding, friction stir welding or the like. This allows integration of the CCB assembly 20 within existing assembly lines for the vehicle.

Although the mounting stanchions 26 shown in Figure 1 are all of a similar form, it should be appreciated that this is for convenience of illustration and that the mounting stanchions 26 may take different forms based on the component that they are to be used with. For example, stanchions 26 used to mount the instrument panel are elongate in form and extend vertically down from the CCB 22 to the vehicle floor to provide sufficient support for the instrument panel, like those shown in Figure 1. Two such stanchions 26 may be used to support the instrument panel; these two stanchions 26 would commonly be placed towards the centre of the CCB 22. On the other hand, a stanchion 26 used to support the steering column may only extend a short distance away from the CCB 22 but may extend a greater distance along the CCB 22 in the length direction.

One benefit of the fact that the CCB 22 is symmetric about a plane P1 normal to the longitudinal axis L is that the steering column could equally be mounted on the left-hand side or right-hand side of the CCB assembly 20, for use with right-hand drive or left-hand drive vehicles. This means the same CCB 22 can be used for both left and right-hand drive vehicles, in contrast to the well-defined state of the art where the diameter of the GCB is smaller on the passenger side than on the driver's side, such that GCBs for right-hand drive and left-hand drive vehicles are mirror images of one another.

The reduction of the diameter of conventional CCBs on the passenger side minimises weight whilst also complying with safety regulations, which are generally more stringent on the driver's side. The driver's side and passenger side portions of conventional CCBs can also be formed of separate sections, which require joining during assembly. By providing a composite CCB 22 that comes in one piece and is symmetrical about a plane P1 normal to the longitudinal axis L, weight is reduced compared to steel GCBs, with the added benefits that passenger side safety is improved and the procedural step of joining two parts of the CCB is obviated. The fact that one CCB 22 can be used in both left and right-hand drive vehicles also streamlines the manufacturing process.

A method of manufacturing the CCB 22 will now be described with reference to Figures 5a to 5d. To manufacture the CCB 22, a former member 60 is first provided to act as a scaffold for uncured composite fibre fabric material 61 to be laid up on the former member 60. The former member 60, like the CCB, extends from a first end 60a to a second end 60b along a longitudinal axis L that defines a length direction. In the embodiment shown in Figures 5a to 5d, the former member 60 is rotationally symmetric around the longitudinal axis L such that the former member 60 has a substantially circular cross-section along the length direction.

The former member 60 has effectively the same shape as the CCB, and so also includes a plurality of first and second regions 62, 64, of which the second regions 64 are narrower than the first regions 62 with respect to a dimension transverse to the longitudinal axis L. Naturally, the external cross-section of the first and second regions 62, 64 of the former member 60 are substantially equal to the respective internal cross-sections of the CCB 22.

The composite fibre fabric material 61 is then applied to the former member 60, as shown in Figure 5a, to create an uncured tubular body 66 in the shape of the former member 60 made entirely of the fabric material. Figure 5a shows the fibre fabric material 61 being braided onto the former member 60. Any suitable braiding process may be used in this step. Although a manual braiding process is possible, it is envisaged that a braiding machine would be used to wind the fibre fabric material 61 onto the former member 60.

Once braiding of the fibre fabric material 61 is complete, resin is then added to the uncured tubular body 66, as shown in Figure 5b. This may occur through submerging the uncured body 66 and former member 60 into a suitable resin bath, or, as shown in Figure 5b, a nozzle 68 may spray the resin onto the uncured body 66 while the body 66 rotates around the longitudinal axis L. Spraying the resin onto the uncured tubular body 66 may achieve a more uniform distribution of resin throughout the uncured body 66 for optimal properties of the final cured CCB 22.

Figure Sc shows the uncured body 66 being cured to form the CCB 22. As is typical with curing processes, the uncured body 66 is placed inside an oven 70 for heat to be applied. The curing temperature is, as will be apparent to those skilled in the art, dependent on the exact resin used in the composite material.

The former member 60 can be solid, in which case it is left inside the CCB 22 after curing and forms a core of the CCB 22. Since the former member 60 will therefore form part of the final cross-car beam assembly 20, it is important that the mass of the former member 60 is minimised and so such former members 60 may be made from an expanded foam or other such suitable material.

In another example, the former member 60 may comprise an inflatable bladder 72 which, in its inflated state, provides a solid base on which the fabric may be braided. Once curing of the tubular body is complete, the inflatable bladder 72 can be deflated and removed from the hollow interior of the newly-formed CCB 22, as shown in Figure 5d. The inflatable bladder 72 therefore provides a temporary former structure on which the fabric may be braided. It is envisaged that a similar result may be achieved by the use of a former member that is made from a dissolvable material.

In either case, it is important that the former member 60 can withstand the heat of the curing oven 70 without melting and/or evaporating. This prevents collapse of the structure of the tubular body 66 before curing has finished. In the case of an inflatable former member 72, this also ensures that the former member 72 may be used again to manufacture further CCBs 22.

Once the CCB 22 has been formed, the metallic end caps 40, mounting collars 24 and mounting stanchions 26 are applied to the CCB 22 to form the cross-car beam assembly 20. As discussed above, the end caps 40 may be applied to the first and second ends 30a, 30b of the CCB 22 via a screw thread engagement or through application of an adhesive to act as a bonding agent between the end cap 40 and the CCB 22. The mounting collars 24 are also attached to the second regions 34 of the CCB 22 through use of an adhesive, with mechanical fixings 54 through the flanges 52 of each collar part 24a, 24b also utilised in some embodiments. The mounting stanchions 26 are fixed to the mounting collars 24 through use of conventional welding techniques.

It will be appreciated that embodiments of the invention may differ from those described above and yet still fall within the scope of the appended claims.

Claims

CLAIMS 2. 3. 4. 6. 8.A cross-car beam (22) of a vehicle, comprising a tubular beam body (30) of a composite material extending in a length direction from a first end (30a) to a second end (30b), wherein the body (30) includes at least one first region (32) that extends a first distance along the beam body (30) in the length direction, and at least one mounting feature (48) to which a respective mounting collar (24) is attachable, wherein the mounting feature (48) is defined by a second region (34) that extends a second distance along the length direction of the beam body (30), and wherein the second region (34) is narrower than the first region (32) in a dimension transverse to the length direction.
The cross-car beam (22) of Claim 1, wherein the first region (32) of the tubular beam body (30) has a constant cross-sectional area.
The cross-car beam (22) of Claim 1 or 2, wherein the tubular beam body (30) is of braided fibre-reinforced composite construction.
The cross-car beam (22) of any preceding claim, wherein the tubular beam body (30) extends along a longitudinal axis (L).
The cross-car beam (22) of Claim 4, wherein the tubular beam body (30) is rotationally symmetric about the longitudinal axis (L).
The cross-car beam (22) of any preceding claim, wherein the tubular beam body (30) is symmetrical about a plane (P1) normal to the longitudinal axis (L).
The cross-car beam (22) of any preceding claim, wherein the first region (32) is one of a plurality of relatively wide first regions (32) and wherein the second region (34) is one of a plurality of relatively narrow second regions (34).
The cross-car beam (22) of any preceding claim, wherein the tubular beam body (30) surrounds a solid core (60).
9. A cross-car beam assembly (20), comprising the cross-car beam (22) of any preceding claim and at least one mounting collar (24), each mounting collar (24) being configured to engage with a respective one of the at least one mounting features (48).
10. The cross-car beam assembly (20) of Claim 9, wherein the at least one mounting collars (24) is metallic.
11. The cross-car beam assembly (20) of Claim 9 or Claim 10, wherein the one or more mounting collars (24) are fixed to respective at least one mounting features (48) by means of an adhesive.
12. The cross-car beam assembly (20) of any of Claims 9 to 11, wherein the at least one mounting collar (24) and each respective second region (34) are configured such that, when the respective mounting collar (24) is received into the respective second region (34), an outer surface of the mounting collar (24) is substantially flush with an adjacent outer surface of the first region (32).
13. The cross-car beam assembly (20) of any of Claims 9 to 12, further comprising a first end cap (40) engaged with the first end (30a) of the tubular beam body (30) and/or a second end cap (40) engaged with the second end (30b) of the tubular beam body (30).
14. The cross-car beam assembly (20) of Claim 13, wherein the first end cap (40) and/or the second end cap (40) is metallic.
15. The cross-car beam assembly (20) of any of Claims 9 to 14, further comprising a mounting stanchion (26) fixed to the respective one or more mounting collars (24).
16. A method of making a cross-car beam assembly (20) for a vehicle, the method comprising: providing an elongate former member (60) having a first end (60a) and a second end (60b) and defining a major axis (L), the former member (60) including at least one first region (62) extending a first distance and at least one second region (64) extending a second distance, wherein the second region (64) is narrow in a direction transverse to the major axis (L) compared to the first region (62); applying composite fabric material (61) to the former member (60) such that an uncured tubular body (66) made of fabric is built up on the former member (60) to take the shape thereof; applying an uncured resin material to the uncured tubular body (66); and curing the un-cured tubular body (66) to form a cured composite tubular body (30) comprising at least one first region (32) and at least one second region (34), wherein the at least one second region (34) is narrow in a direction transverse to the major axis (L) compared to the at least one first region (32).
17. The method of Claim 16, wherein the former member (60) is a solid body.
18. The method of Claim 16, wherein the former member is an inflatable body (72) and the method includes deflating the former member (72) following the curing step and removing the former member (72) from the interior of the cured tubular body (30).
19. The method of any of Claims 16 to 18, further comprising applying a first end cap (40) to the tubular body and/or applying a second end cap to the tubular body (30).
20. The method of Claim 19, wherein the first and/or second end cap (40) are applied to the tubular body before it is cured.
21. The method of Claim 19, wherein the first and/or second end cap (40) are applied to the tubular body after it is cured.
22. The method of any of Claims 16 to 21, further comprising applying a mounting collar (24) to respective ones of the of the relatively narrow second regions (34) of the cured tubular body (30).
23. The method of Claim 22, further comprising applying a bonding agent to faying surfaces of the at least one mounting collar (24) and the respective second region (34).
24. The method of either Claim 22 or Claim 23, further comprising fixing a mounting stanchion (26) to respective ones of the mounting collars (24).