Railway vehicle body wall structure

Abstract

To provide a vehicle body wall structure for a railway vehicle capable of helping dispersion and reduction of peak stress and reducing the possibility of separating an FRP system from a panel.SOLUTION: A wall structure 10 for forming a wall of a railway vehicle body includes a metal panel 20 in which an opening 21 is formed and a fiber reinforced plastic reinforcing system 30 attached to the metal panel 20 at a corner 22 of the opening 21. The FRP reinforcing system 30 includes a laminate of FRP laminae arranged such that as the lamination proceeds from a base lamina 31, the area of each lamina in the laminate becomes smaller than the area of the previous lamina.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a wall structure for forming the walls of a rail vehicle body. [Background technology]

[0002] Rail vehicles, especially electrified rail vehicles, have a lower environmental impact than other forms of transportation such as road transport, in part because their higher passenger densities mean that they consume less electricity per passenger per unit distance than other forms of transportation.

[0003] However, there is a continuing incentive to reduce the mass of trains and other rail vehicles in order to further reduce the electricity consumption associated with these vehicles and thereby reduce the carbon dioxide emissions associated with operating such vehicles.

[0004] A known method of reducing the mass of rail vehicles is to reduce the mass of the rail vehicle body structure. Typically, the walls of the car body are made of metal panels. The mass of the car body can be reduced by reducing the gauge of the metal panels or by using a material with a lower density. For example, as shown by JP 2002-264803 A, such walls can be constructed of a double-skin material with ribs extending between two metal panels, which can further reduce the gauge of the material used for the panels, while the ribs help provide adequate strength and rigidity. However, the car body is required to withstand stresses from both its own weight and the running loads.

[0005] Openings made in vehicle body walls for windows, doors, vents, etc. create areas of stress concentration around such openings. The stress concentration problem is particularly severe at the corners of the openings because the corners further concentrate stresses in the surrounding metal panels.

[0006] Thus, when attempting to reduce the mass of a vehicle body, stresses near openings in the vehicle body, particularly at the corners of such openings, are often a limiting factor in how much the mass of the vehicle body can be reduced by material selection and / or reduction in material thickness.

[0007] To address this limiting factor, it is known to reinforce the area of ​​the metal panel surrounding such an opening with a fibre-reinforced-plastic (FRP) component which is bonded to the metal panel in that area and acts to strengthen the wall in the area where stress is most concentrated. Such a construction can reduce the mass of the metal panel whilst still providing a bodywork which can withstand the stresses imposed thereon in use.

[0008] However, existing body wall structures using FRP members do not optimize the strength / mass ratio.In addition, in body structures using FRP members, the difference in thermal expansion coefficient between the material of the FRP member and the metal of the panel often places high stress on the adhesive layer that bonds the FRP member to the metal panel, which can lead to peeling between the FRP member and the panel.

[0009] The present invention has been devised in view of the above points. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2002-264803 A Summary of the Invention

[0011] In a first aspect of the present disclosure, a wall structure for forming a wall of a rail vehicle car body is provided. The wall structure comprises a metal panel having an opening formed therein and a fiber reinforced plastic (FRP) reinforcement system attached to the metal panel at a corner of the opening. The FRP reinforcement system comprises a stack of FRP laminas arranged such that, as the stack proceeds from a base lamina, the area of ​​each lamina in the stack is smaller than the area of ​​the previous lamina. Advantageously, by providing a wall structure having such a multi-layer FRP reinforcement system, the strength-to-mass ratio of the FRP reinforcement system can be improved, for example, compared to an FRP reinforcement system having only a single FRP lamina of uniform thickness. Also, the amount of FRP used in the wall structure can be reduced, thereby reducing the environmental burden associated with the manufacture of the FRP system. Furthermore, the tapering area of ​​the stack laminas can reduce peak stresses due to differences in coefficient of thermal expansion (CTE) between the FRP and the metal of the panel. In particular, the gradual area reduction allows the thickness of the FRP system to gradually transition from a minimum thickness at the ends of the FRP system to a maximum thickness at a more central location of the FRP system, which gradual transition can help spread and reduce peak stresses, thereby reducing the likelihood of delamination of the FRP system from the panel.

[0012] The laminas of the FRP reinforced system may be sized such that, proceeding from a base lamina, the area of ​​each successive lamina in the stack is equal to or less than a threshold percentage of the area of ​​the previous lamina. The threshold percentage may be 80%, preferably 70% or 60%. The laminas of the FRP reinforced system may be shaped such that, proceeding from a base lamina, the boundary of each successive lamina lies entirely within the boundary of the previous lamina when viewed in the stacking direction.

[0013] An FRP system may be constructed of only two laminas, where the base lamina is the first lamina, the next lamina is the second lamina, etc. However, an FRP system may be constructed of more than two laminas, where the base lamina is the first lamina, the next lamina is the second lamina, the subsequent lamina is the third lamina, etc. The number of laminas in an FRP system may be determined according to considerations such as the desired amount of reinforcement of the metal panel by the FRP system, the desired mass of the resulting wall structure, the available space for the system, CTE differences, etc.

[0014] The fibers in the FRP reinforcement system may be composed of, for example, one or more of carbon fibers, glass fibers, and aramid fibers. The fibers are typically continuous. Each lamina may be formed from one or more layers of fibers, for example in the form of lay-up prepreg sheets. Within each layer, the fibers may be multidirectional, e.g., woven, or unidirectional.

[0015] The resin matrix in the FRP reinforcement system may be composed of, for example, one or more of epoxy resins, acrylic resins, and urethane resins.

[0016] The metal panels may be formed, for example, from an aluminum alloy or steel (eg, stainless steel).

[0017] A wall structure may be constructed from a plurality of FRP reinforcement systems. For example, an opening, such as a substantially rectangular opening, may have multiple corners, and each FRP reinforcement system may be attached to a metal panel at a respective corner of the opening. Additionally or alternatively, a wall structure may be constructed from a plurality of openings, each having one or more FRP reinforcement systems.

[0018] The opening may be a window opening, whereas the FRP strengthening system may also be applied to a door opening, although door openings are generally larger than window openings and therefore tend to require more substantial, e.g., metal-based, strengthening and reinforcing systems.

[0019] Laminated laminas of an FRP strengthened system may be bonded together to form a monolithic FRP strengthened system attached to one side of a metal panel. The base lamina of the laminate is usually the lamina in the laminate closest to the metal panel. In wall construction situations used to form single-skin rail car body walls, such monolithic FRP strengthened systems are usually attached to the interior side of the metal panel and may be conveniently covered with a non-structural, decorative interior panel.

[0020] Alternatively, if the FRP system is not a monolithic FRP-strengthened system, a base lamina of the FRP-strengthened system may be attached to one side of a metal panel and another lamina of the laminate attached to the other side of the metal panel, sandwiching the metal panel between the laminas. In the context of a wall construction used to form a double-skinned rail car body wall having spaced-apart outer and inner metal panels, the base lamina may be attached to the side of the inner metal panel facing the interior of the car body and another lamina of the laminate attached to the inner metal panel on its opposite side (i.e., in the cavity between the inner and outer metal panels). This arrangement allows the FRP system to occupy a smaller volume within the car body. It should be noted that a number of ribs may extend between the outer and inner metal panels. In that case, the lamina located in the cavity between the inner and outer metal panels may have one or more fingers extending between adjacent ribs.

[0021] The end of the FRP reinforcement system closest to the corner of the opening may be offset from its perimeter to leave a margin of the metal panel at the corner of the opening not covered by the FRP reinforcement system. This margin may be filled with an edge fillet of adhesive to strengthen the bond between the FRP system and the metal panel. Furthermore, providing such a margin allows for a greater tolerance between the geometry of the opening corner and the geometry of the FRP system. The appropriate width of the margin of the metal panel at the corner of the opening may be at least 1 mm and / or up to 20 mm, depending on factors such as the mechanical properties of the metal panel, the FRP and the adhesive material.

[0022] The edges of the laminates in the FRP strengthening system closest to the corner of the opening may coincide when viewed in the laminate direction.

[0023] The base lamina of the FRP system may have a first fiber direction substantially aligned with the longitudinal direction of the vehicle body and a second fiber direction substantially aligned tangentially with the periphery of the opening at the corner. Such an arrangement of fibers within the base lamina is particularly effective in increasing the bending and shear stiffness and strength of the wall structure at the corner of the opening. Other fiber directions, if present, may be selected to reduce warpage deformation induced by temperature changes during manufacture, for example.

[0024] The wall structure may further include an elastic, e.g., rubber-like, adhesive material that bonds the FRP reinforced system to the metal panel, the elastic adhesive material being relatively flexible compared to the FRP reinforced system and the metal panel. Such an adhesive material may further reduce peak stresses induced by the CTE difference, and thus reduce the risk of the FRP reinforced system peeling off from the metal panel. Furthermore, the elastic adhesive material may have damping properties that reduce the amount of vibration and noise transmitted from the outside of the railcar body through the wall structure. The elastic adhesive material may be composed of, for example, one or more of an epoxy adhesive, an acrylic adhesive, and a urethane adhesive. In general, a lower modulus of elasticity of the adhesive material may allow for a smaller bond thickness and a smaller offset of the end of the FRP reinforced system from the periphery of the corner of the opening.

[0025] When the wall structure comprises a plurality of FRP reinforcement systems, two adjacent FRP reinforcement systems may be for adjacent corners of the same opening (e.g., adjacent upper and lower corners of the opening), respectively, and the base lamina of the adjacent FRP reinforcement systems may be formed from a single lamina extending seamlessly from corner to corner of the same opening. Advantageously, such a structure may increase the bending strength and stiffness of the wall structure in the region between the adjacent corners of the opening. Furthermore, the number of parts to be attached to the metal panel may be reduced, simplifying the manufacture of the wall structure. The corner-to-corner extending portion of the base lamina of the FRP reinforcement system may have a fiber direction that substantially coincides with the direction between the two adjacent corners through which the base lamina extends.

[0026] Additionally or alternatively, when the wall structure comprises a plurality of FRP reinforcement systems and the metal panel comprises a plurality of openings, two adjacent FRP reinforcement systems may be for adjacent corners of adjacent openings, respectively (e.g., two adjacent top corners or two adjacent corners and a bottom corner), and the base lamina of the adjacent FRP reinforcement systems may be formed from a single lamina extending from corner to corner of said adjacent openings without interruption. Advantageously, such a structure may increase the shear strength and stiffness of the wall structure in the area between the two adjacent openings. Furthermore, the number of parts to be attached to the metal panel may be reduced, simplifying the manufacture of the wall structure. The portion of the base lamina of the FRP reinforcement system extending from the corner of one opening to the corner of the other opening may have a fiber direction that substantially coincides with the direction between the two adjacent corners through which the base lamina extends. Advantageously, this may further improve the increase in bending stiffness provided by the structure.

[0027] In wall constructions as described above, where the base lamina of adjacent FRP reinforcement systems is formed from a single lamina extending seamlessly between the FRP reinforcement systems, one or more further laminas on the outside of the FRP reinforcement systems at the corners of the opening(s) may be laminated onto the single lamina forming the base lamina, thereby significantly strengthening and stiffening the metal panel in other areas away from the corners of the opening.

[0028] The wall structure may form the side walls of a rail vehicle body.

[0029] In a second aspect of the present disclosure, there is provided a rail vehicle carbody having a wall formed with a wall structure according to the first aspect of the present disclosure. The second aspect may incorporate any of the features defined above in relation to the first aspect. The present invention includes combinations of the described aspects and preferred features, unless such combinations are expressly not permitted or explicitly avoided. Aspects and embodiments of the present disclosure will now be described with reference to the accompanying figures. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 shows a railroad vehicle body. [Diagram 2] FIG. 2 is a diagram showing a part of a wall structure for forming a side wall of a railcar body. [Diagram 3] FIG. 3 is a cross-sectional view of the wall structure of FIG. 2 taken along line A-A'. [Figure 4] FIG. 4 is a detailed view of the FRP reinforcement system of the wall structure of FIG. [Diagram 5] FIG. 5 shows a portion of a double-skin wall structure for forming the side walls of a train body. [Figure 6] FIG. 6 is a cross-sectional view of the wall structure of FIG. 5 taken along line BB'. [Figure 7A] FIG. 7A is a detailed view of the FRP reinforcement system of the wall structure of FIG. [Figure 7B] FIG. 7B is a detailed view of the base lamina of the FRP reinforcement system. [Figure 7C] FIG. 7C is a detailed view of the second lamina of the FRP reinforcement system. [Figure 8] FIG. 8 illustrates a portion of another wall structure for forming the side wall of a train car body, the wall structure being constructed with multiple openings and multiple FRP reinforcing systems. [Figure 9] FIG. 9 shows a variation of the wall structure shown in FIG. [Figure 10] FIG. 10 shows a further variation of the wall structure shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Aspects and embodiments of the present disclosure will now be described with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art.

[0032] Figure 1 is a schematic perspective view from below of a rail vehicle carbody 1. The carbody has side walls 2, a floor 3, a roof (not shown in Figure 1) and end walls 4. Door openings 5 ​​and window openings 21 are formed in the side walls. Below the floor 3 is an underfloor bolster beam 6 for mounting bogies. The rail vehicle carbody utilises a wall structure, described in more detail below, to form the side walls 2. However, the same or similar structures may also be used, where appropriate, to form the floor 3, roof, end walls 4 and any internal bulkheads.

[0033] 2 shows a portion of a wall structure 10 for forming a side wall 2 of a car body 1 of such a rail vehicle. The wall structure 10 comprises a metal panel 20 having window openings 21 formed therein, and a plurality of fiber reinforced plastic (FRP) strengthening systems 30 attached to the metal panel 20 at respective corners 22 of each opening 21. However, the invention is not limited to strengthening systems for window openings, and it can be appreciated that a train car body may be provided with a variety of different types of openings to which strengthening systems may be applied (e.g. emergency escape hatches, access hatches, doors, ventilation holes, etc.).

[0034] The metal panels 20 are typically fabricated from an aluminum alloy, but may also be fabricated from steels such as stainless steel. The carbody of a rail vehicle provides the structural shell of the carriage in which passengers are transported. It is important that the carbody is able to withstand the forces exerted on it by its own weight and the loads of the moving train. In particular, the stresses in a carbody supported at both ends by bolster beams 6 resemble a beam bending under its own weight, generating shear stresses that act along the length of the carbody and generally vertically.

[0035] The window opening 21 in the metal panel 20 reduces the overall stiffness of the panel and increases the load that must be carried by the remaining metal. Additionally, the corners 22 of the opening 21 act as stress raisers in the areas of the metal panel 20 adjacent the corners 22.

[0036] To address such concerns, as shown in Figure 2, the wall structure 10 has a respective FRP reinforcement system 30 attached to the metal sheet 20 at each corner 22 of the opening 21 in the metal sheet 20. The FRP reinforcement systems 30 locally strengthen and stiffen the wall structure at the corners 22 such that the thickness of the metal sheet 20 can be reduced without compromising the ability of the wall structure to withstand forces acting thereon.

[0037] Each FRP reinforcement system 30 is a multi-layered structure, consisting of a stack of laminas 31 and 32 arranged such that, proceeding from a base lamina 31, the area of ​​each lamina in the stack is smaller than the area of ​​the previous lamina. In the example of FIG. 2, each FRP system 30 comprises a first (base) lamina 31 and a second lamina 32. However, other FRP systems 30 may be composed of three or more stacked laminas, each successive lamina having a smaller area than the preceding lamina. As already mentioned, a first advantage of this wall structure 10 is that the metal panel 20 can be made thinner by reducing the load on the metal panel 20 near the corners 22 of the opening 21. Furthermore, the tapering of the laminas in the stack allows the fiber and resin materials used in the FRP system 30 to be concentrated in the areas of the panel 20 where the reinforcement and stiffness requirements are highest, reducing the amount of fiber and resin materials that would be used if the FRP reinforcement system was of uniform thickness throughout. This improves the strength-to-mass and strength-to-cost ratios of the wall structure 10.

[0038] The fibers used in the FRP system 30 may be, for example, one or more of carbon fibers, glass fibers, and aramid fibers. The resin used in the FRP system 30 may be, for example, one or more of epoxy resins, acrylic resins, and urethane resins. Factors determining the selection of fibers and resins include stiffness, strength, toughness, mass, cost, and coefficient of thermal expansion (CTE).

[0039] Furthermore, the laminas in the FRP reinforcement system 30 in FIG. 2 are shaped such that as stacking proceeds from the first (base) lamina 31, the boundary of the second lamina 32 is located entirely within the boundary of the first (base) lamina 31.

[0040] In addition to material savings, another advantage of the construction of the FRP system of the present invention relates to thermal stresses that arise in metal-FRP structures. Typically, known FRP components used to reinforce and stiffen metal panels 20 in rail car bodies are attached to the metal panels 20 using an adhesive layer. However, typical metal alloys used in train car body walls, such as aluminum alloys and steel, have a CTE that is substantially greater than the CTE of the FRP component material.

[0041] The metal panel 20 and the FRP component undergo differential expansion due to differences in the CTE of the materials, resulting in large peak stresses in the adhesive bond that bonds the two together. The magnitude of the peak stresses and / or the stress cycling due to temperature cycling can cause the adhesive bond to break down and the FRP component to delaminate from the metal panel 20, so that the FRP component no longer strengthens and stiffens the metal panel 20.

[0042] FIG. 3 shows a cross-section of the wall structure 10 of FIG. 2 along line A-A', where the FRP system 30 is attached to the metal panel 20 by an adhesive layer 33. In FIG. 3, the thickness of the laminate in the FRP system 30 is non-uniform across the area of ​​the metal panel 20 to which the FRP system 30 is attached. Moving within the laminate from the base lamina 31, each successive lamina has a smaller area than the preceding lamina. The progressive reduction in the area of ​​the laminas allows for a gradual transition in the thickness of the FRP system from a minimum thickness at the ends of the FRP system to a maximum thickness at a more central location of the system, which helps to diffuse and reduce peak stresses that arise in the adhesive layer 33 from differential thermal expansion and contraction. Thus, the risk of the FRP system 30 delaminating from the metal panel 20 is reduced and the reliability of the wall structure 10 is improved.

[0043] Furthermore, because the material of the adhesive layer 33 in Figure 3 is highly elastic (e.g., rubber-like) and more flexible than the FRP system 30 and the metal panel 20, the adhesive layer 33 can elastically, and therefore reversibly, deform to accommodate differential thermal expansion and contraction. However, as shown in Figures 2 and 3, within a given FRP reinforced system 30, the ends of the lamina closest to the corners 22 of the opening 21 are typically aligned with each other when viewed along the lamination direction of that system. This alignment of the lamina ends does not necessarily increase the stresses induced in the adhesive layer, since the components of the in-plane stresses in the adhesive layer 33 and the metal panel 20 perpendicular to the line of the opening perimeter must be zero at the perimeter.

[0044] In Figure 3, the FRP system 30 is attached to the metal panel 20 such that the aligned edges of the stack of lamina are also aligned with the periphery of the opening 21. Figure 4 shows a possible alternative arrangement, where the FRP system 30 is attached to the metal panel 20 such that the aligned lamina edges of the FRP system 30 are offset from the periphery of the opening 21, leaving a margin 23 of metal at the corner 22 of the opening 21 that is not covered by the FRP reinforcement system 30. Filling this margin 23 with an edge fillet of adhesive provides a strong bond between the FRP reinforcement system 30 and the metal panel 20 and allows for a greater tolerance between the shape of the opening corner 22 and the shape of the FRP reinforcement system 30. As long as the width of the margin is relatively small, the aligned edges of the lamina along the margin do not significantly increase the stresses developed in the adhesive layer 33.

[0045] The orientation of the fibers within the laminas of the FRP system 30 may also affect the strength and stiffness of the FRP system 30 in different directions, and therefore the properties of the resulting wall structure 10. For example, the base lamina 31 may include fibers that are generally aligned in two directions, a first fiber direction aligned substantially along the longitudinal direction of the vehicle body (i.e., horizontally in FIG. 2 ) and a second fiber direction aligned substantially along the tangential direction of the periphery of the opening 21 at the corner 22. The alignment of the fibers in both the first and second fiber directions within the base lamina 30 improves the bending stiffness and strength as well as the shear stiffness and strength of the resulting FRP system 30 and wall structure 10. Similarly, the fiber orientation within one or more additional laminas forming the FRP system 30 may be selected to affect the strength and stiffness of the FRP system 30.

[0046] The wall structure 10 shown in Figures 2, 3 and 4 is constructed by bonding laminated laminae 31 and 32 of each FRP system 30 to form an integrated FRP system 30, and attaching this to one side of a metal panel 20. Figures 5 and 6 show modified versions of the wall structure 10.

[0047] The wall structure 10 in Figures 5 and 6 is a double skin having spaced apart interior and exterior metal panels 20a, 20b. Ribs 24 extending parallel to each other along the longitudinal direction of the vehicle body also extend across the cavity between the interior and exterior metal panels 20a, 20b to stiffen and strengthen the wall structure 10. In Figure 6, the base lamina 31 of the FRP system 30 is attached to the side of the interior metal panel 20a facing the vehicle interior, while the second lamina 32 is attached to the opposite side of the interior metal panel 20a, i.e., in the cavity between the interior and exterior metal panels 20a, 20b. The base lamina 31 and the second lamina 32 thus sandwich the interior metal panel 20a. If the FRP system 30 consists of more than one lamina, the additional laminas may be located on both sides of the metal panel 20. The modified wall structure 10 shown in Figures 5 and 6 requires additional installation of laminas and panels, but can increase the available interior space within the train body, especially in double skin wall constructions, by reducing the number of laminas on the inward facing side of the inner metal panel 20a.

[0048] FIG. 7A shows the modified wall structure 10 of FIG. 5 and FIG. 6 in detail, particularly the FRP system 30. FIG. 7B shows the shape of the base lamina 31, and FIG. 7C shows the shape of the second lamina 32. The reinforcing ribs 24 stop short of the periphery of the opening 21 in the inner 20a and outer 20b metal panels, such that the margins of the metal panel 20 adjacent the periphery of the opening 21 are not blocked by the ribs 24. The base lamina 31 is attached to the inner side of the inner metal panel 20a. The second lamina 32 has a circumferential portion 36 shaped to extend along the edge of the metal panel 20. The second lamina 32 also has finger portions 37 extending away from the circumferential portion 36 of the lamina 32, such that when the lamina is attached to the inner metal panel 20a, the finger portions 37 extend away from the periphery of the opening 21 between adjacent ribs 24.

[0049] FIG. 8 shows a portion of a modified wall structure 10 having adjacent openings 21a and 21b aligned such that the top corners 22a and 22c of the two openings are adjacent to each other and the bottom corners 22b and 22d of the two openings are similarly adjacent to each other. In a typical car body bending under its own weight, one of the areas of the car body that is most highly stressed is the area of ​​the metal panel 20 located between the two adjacent corners 22 of the two adjacent openings 21. In FIG. 8, FRP systems 30a and 30c are attached to the metal panel 20 at the adjacent top corners 22a and 22c of the two adjacent openings 21a and 21c, respectively. Each of the FRP systems 30a and 30c consists of a respective base lamina 31a and 31c and a respective second lamina 32a and 32c. To increase the shear strength and stiffness of the area of ​​the metal panel 20 located between adjacent opening corners 22a and 22c, the base laminas 31a and 31c of adjacent FRP reinforcement systems 30a and 30c are formed from a single lamina that extends seamlessly from corner 22a to corner 22c (i.e., FRP reinforcement systems 30a and 30c have a common base lamina), further increasing the strength and stiffness of the wall in high stress areas. In addition, this structure reduces the number of parts that are bonded to the metal panel 20, simplifying the manufacture of walls having this wall structure 10. Similarly, FRP systems 30c and 30d located at the two bottom corners 22b and 22d of the same openings 21a and 21c share a single base lamina that extends seamlessly from corner 22b to corner 22d.

[0050] Returning to the fiber orientation within the base lamina 31 of the FRP system 30 discussed above in connection with Figure 2, it can be seen that in the wall structure 10 of Figure 8, the first fiber orientation within the unbroken common base lamina of adjacent FRP systems 30 is substantially aligned with the length of the vehicle body such that the fibers themselves extend unbroken between adjacent FRP systems, further enhancing the strength and stiffness of the resulting FRP system 30 and wall structure 10.

[0051] FIG. 9 shows a part of a variation of the wall structure 10 shown in FIG. 8. FRP systems 30a and 30b form part of the wall structure 10 and are attached to the metal panel 20 at adjacent corners 22a and 22b, respectively, of the same opening 21a. Similarly, FRP systems 30c and 30d form part of the wall structure 10 and are attached to the metal panel 20 at adjacent corners 22c and 22d, respectively, of a second opening 21c. Each of the four FRP systems 30a-d comprises a respective base lamina 31a-d and a respective second lamina 32a-d. As in FIG. 8, the base lamina 31 of the FRP system 30 attached to the metal panel 20 at adjacent corners 22 of adjacent openings 21 is formed from a single lamina. The lamina extends uninterrupted from the corner 22 of one opening 21 to the adjacent corner 22 of the adjacent opening 21. The wall structure 10 of Fig. 9 differs from the wall structure 10 of Fig. 8 in that the base laminas 31a, 31b of the FRP systems 30a, 30b attached to the metal panel 20 at adjacent corners 22a, 22b of the same opening 21a are formed from a single lamina with a central portion 34 extending seamlessly between the two adjacent corners 22a, 22b. Furthermore, the base laminas 31c, 31d of the FRP systems 30c and 30d attached to the metal panel 20 at adjacent corners 22c and 22d of the same opening 21c are formed from the same single lamina as that of the FRP systems 30a, 30b. Thus, the base laminas 31a-d of the FRP systems 30a-d are all formed from a single lamina extending seamlessly between the four corners 22a-d of the two mutually adjacent openings 21a and 21c (i.e., all four FRP systems 30a-d of Fig. 9 have a common base lamina 30). Compared to the wall structure shown in FIG. 8, the wall structure 10 of FIG. 9 also increases bending stiffness and strength in the areas of the metal panels 20 that extend between adjacent corners of the same opening.

[0052] Where the common base lamina 30 extends between adjacent corners 22 of the same opening 21, a third fiber direction may be present within the unbroken common base lamina 30. This third fiber direction is substantially aligned with the direction in which the central portion 34 of the common base lamina extends (i.e., vertically in FIG. 9), so that the fibers again extend unbroken between adjacent FRP systems. This further improves the bending stiffness and strength of the resulting FRP system 30 and wall structure 10.

[0053] FIG. 10 shows a part of a variation of the wall structure 10 shown in FIG. 9, in which a further lamina 35 external to the FRP reinforcement system is laminated onto a single lamina forming the base lamina 31a-d of four adjacent FRP reinforcement systems 30a-d. The further lamina 35 is located on a central portion 34 of the common base lamina. Advantageously, the further lamina 35 can thereby contribute to improving the bending stiffness and strength of the wall structure 10. However, the location of the further lamina 35 is not necessarily limited to the central portion 34 of the common base lamina. Although only a single further lamina 35 is shown in FIG. 10, other further laminas 35 may be laminated onto the single lamina forming the base lamina 31 of adjacent FRP systems 30, either in a single stack or forming multiple further stacks, as required.

[0054] The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, may be expressed in their specific form, or in terms of means for performing a disclosed function, or a method or process for obtaining a disclosed result, as appropriate, and may be utilized to realize the invention in various of its forms, either separately or in any combination of such features.

[0055] While the present invention has been described in conjunction with the exemplary embodiments set forth above, many equivalent modifications and variations will be apparent to those skilled in the art given this disclosure. Accordingly, the exemplary embodiments of the present invention set forth above are considered to be illustrative and not limiting. Various changes can be made to the described embodiments without departing from the spirit and scope of the present invention.

[0056] For the avoidance of doubt, the theoretical explanations provided herein are provided for the purpose of enhancing the understanding of the reader and the inventors do not wish to be bound by these theoretical explanations.

[0057] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0058] Throughout this specification, including the claims which follow, unless the context otherwise requires, the words "comprise" and "include," as well as variations such as "comprises," "comprising," and "including," are understood to imply the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of other integers or steps or groups of integers or steps.

[0059] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, it is understood that the particular value forms another embodiment by use of the antecedent "about." The term "about" with respect to numerical values ​​is arbitrary and means, for example, ±10%.

Claims

1. A wall structure for forming a wall of a railroad vehicle body, comprising: The wall structure comprises: A metal panel having an opening formed therein; a FRP reinforcement system attached to the metal panel at a corner of the opening; Equipped with The FRP reinforcement system comprises a stack of FRP laminas stacked from a base lamina and arranged such that the area of ​​each lamina in the stack is smaller than the area of ​​the previous lamina; the wall structure being comprised of a plurality of the FRP reinforcement systems; Two adjacent FRP reinforcement systems are each for adjacent corners of the same opening, and the base lamina of the adjacent FRP reinforcement systems is formed from a single lamina extending seamlessly from corner to corner of the same opening; one or more further laminas external to the FRP reinforcement system at the corners are laminated onto a single lamina forming the base lamina; wall structure.

2. 2. The wall structure of claim 1, The opening is a window opening. wall structure.

3. 2. The wall structure of claim 1, the stacked laminas of the FRP reinforcement system are bonded together to form a monolithic FRP reinforcement system attached to one side of the metal panel; wall structure.

4. A wall structure for forming a wall of a railroad vehicle body, comprising: The wall structure comprises: A metal panel having an opening formed therein; a FRP reinforcement system attached to the metal panel at a corner of the opening; Equipped with The FRP reinforcement system comprises a stack of FRP laminas stacked from a base lamina and arranged such that the area of ​​each lamina in the stack is smaller than the area of ​​the previous lamina; the base lamina of the FRP reinforcement system is attached to one side of the metal panel; Another lamina in the laminate is attached to the other side of the metal panel, sandwiching the metal panel between the laminas. wall structure.

5. 5. The wall structure according to claim 4, which forms a double skin wall of a railroad vehicle body, having outer and inner metal panels spaced apart; the base lamina is attached to one side of the metal panel on the inside facing the vehicle body; Another lamina in the laminate is attached to the inner metal panel on the opposite side to the base lamina. wall structure.

6. 2. The wall structure of claim 1, an end of the FRP reinforcement system nearest a corner of the opening is offset from its periphery to leave a margin of the metal panel at the corner of the opening not covered by the FRP reinforcement system; wall structure.

7. 2. The wall structure of claim 1, the ends of the lamina of the FRP reinforcement system closest to the corner of the opening are coincident when viewed in their stacking direction; wall structure.

8. 2. The wall structure of claim 1, the base lamina having a first fiber direction substantially aligned with a longitudinal direction of the vehicle body and a second fiber direction substantially tangentially aligned with a periphery of the opening at the corner. wall structure.

9. 2. The wall structure of claim 1, a resilient adhesive adheres the FRP reinforcement system to the metal panel; the elastic adhesive is relatively flexible compared to the FRP reinforcement system and the metal panel; wall structure.

10. A railroad car body having a wall formed of the wall structure according to claim 1.

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