Structure and method for terminal fixing of fiber-reinforced plastic filament body, and cylindrical cushioning material

Abstract

The purpose of the present invention is to provide a terminal fixing structure having high productivity. In a CFRP cable terminal fixing structure, a cylindrical cushioning material is put on a terminal part of a CFRP cable and a part covered with the cylindrical cushioning material is sandwiched and fixed in a terminal socket by a wedge. The cylindrical cushioning material is shaped so as to have a cylindrical hollow part having a diameter corresponding to the diameter of the CFRP cable by spirally winding an elongated laminated sheet (2a) that is obtained by laminating a plurality of metal mesh sheets (2A-2P) obtained by weaving fine metal wires, or by curling a rectangular laminated sheet or a metal mesh sheet.

Description

End fixing structure and method for fiber-reinforced plastic wire body, and cylindrical buffer material

[0001] This invention relates to a structure and method for fastening a terminal socket (fixing tool) to the end of a fiber-reinforced plastic filament. This invention also relates to a cylindrical buffer material that buffers the force applied to the fiber-reinforced plastic filament from its surroundings.

[0002] Fiber-reinforced plastics (FRP), a composite material of fiber and plastic, has high strength, and cables (ropes, rods) made from FRP are lighter than steel stranded wire and have excellent properties such as high corrosion resistance and non-magnetic properties. Fiber materials used in FRP include carbon fiber, glass fiber, and Kevlar (registered trademark) fiber, while plastic materials used in FRP include epoxy resin, polyamide resin, and phenolic resin. FRP cables are used, for example, as tendons for prestressed concrete and as reinforcing materials for electric wires.

[0003] While FRP cables have the same high longitudinal tensile strength as steel stranded wires, they are vulnerable to localized shear forces and surface scratches. For this reason, if a socket is fixed to the terminal of an FRP cable by directly inserting a wedge into it, as with steel stranded wires, slippage occurs due to shear failure or surface failure, and it is not possible to achieve a high level of anchorage between the cable and socket.

[0004] Patent Document 1 discloses a terminal fixing structure and method in which the end of a carbon fiber reinforced plastic cable (CFRP cable) is covered with a cylindrical buffer material comprising a friction buffer sheet and a SUS (Steel Use Stainless) mesh sheet, and the covered portion of the cylindrical buffer material is sandwiched between a wedge and wedged into a terminal socket. The cylindrical buffer material can buffer the local shear force caused by the wedge, making it less likely that the CFRP cable will suffer shear failure or surface failure at the wedge position.

[0005] Japanese Patent Application Laid-Open No. 2020-153187

[0006] The friction buffer sheet that constitutes the cylindrical buffer material is composed of a sheet material with cushioning function in the thickness direction, such as synthetic fiber cloth, nonwoven fabric, paper, or film, with alumina particles bonded to both sides. On the other hand, the SUS mesh sheet that constitutes the cylindrical buffer material is a woven wire mesh made of many thin SUS wires. To manufacture the cylindrical buffer material, two types of sheets must be prepared: the friction buffer sheet and the SUS mesh sheet. Because the friction buffer sheet and the SUS mesh sheet are generally procured from different sources, the productivity of the end-fixed structure (cylindrical buffer material) of Patent Document 1 cannot be said to be necessarily high.

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide an end fixing structure having a cylindrical cushioning material that can be easily produced.

[0008] Fiber-reinforced plastic filaments are made by compounding (mixing) fiber materials such as carbon fiber, glass fiber, and Kevlar fiber with resin materials such as epoxy resin, polyamide resin, and phenolic resin, forming them into filaments. Filaments have a uniform cross-sectional shape in the longitudinal direction, typically a circular cross-section, and are longer than their diameter. Examples of filaments include cables, ropes, and rods.

[0009] The terminal fixing structure of a fiber-reinforced plastic filament according to this invention is characterized in that a cylindrical cushioning material is placed over the end portion of the fiber-reinforced plastic filament, and the portion covered with the cylindrical cushioning material is clamped and fixed within the terminal socket by a wedge, and the cylindrical cushioning material is a metal mesh sheet woven with fine metal wires shaped to have a cylindrical hollow with a diameter that matches the diameter of the filament.

[0010] According to this invention, the cylindrical cushioning material is made of only a metal mesh sheet, which allows for high productivity, and as a result, the productivity of the terminal fixing structure provided with the cylindrical cushioning material is also high.

[0011] The cylindrical cushioning material is a metal mesh sheet woven from fine metal wires, shaped to have a cylindrical hollow with a diameter that corresponds to the diameter of the filament. Because the metal mesh sheet is woven from fine metal wires, fine irregularities are formed on its front and back surfaces, making it uneven. Such a metal mesh sheet with fine irregularities on its front and back surfaces provides cushioning in the thickness direction and can adequately cushion (reduce) the local shear force caused by a wedge without the need for a separate cushioning component. Furthermore, because the metal mesh sheet has fine irregularities on its surface, it also has high longitudinal friction, eliminating the need for a separate component (friction sheet) designed to increase friction.

[0012] In one embodiment, the cylindrical cushioning material is composed of a laminated sheet in which a plurality of the metal mesh sheets, each having a length greater than the length of the wedge, are stacked together, and the degree of cushioning in the thickness direction of the cylindrical cushioning material can be controlled by the number of layers of the metal mesh sheets constituting the laminated sheet and the number of turns (windings) of the laminated sheet.

[0013] In one embodiment, the cylindrical cushioning material is the laminated sheet rolled up.

[0014] In another embodiment, the cylindrical cushioning material is formed by rolling and overlapping the metal mesh sheet having a length greater than the length of the wedge multiple times, and the degree of cushioning in the thickness direction of the cylindrical cushioning material can be controlled by the number of times the metal mesh sheet is wound.

[0015] In yet another embodiment, the cylindrical cushioning material is a long, thin laminated sheet formed by stacking multiple metal mesh sheets, which is spirally wound over a length that exceeds the length of the wedge.

[0016] The end portion of the fiber-reinforced plastic wire is wedged into the terminal socket. For example, the end portion of the fiber-reinforced plastic wire is clamped by a wedge split in half lengthwise (two pieces (two halves)) or a wedge split into three or four pieces lengthwise (three pieces, four pieces) and pushed into the terminal socket. The terminal socket has a wedge-shaped hollow. The wedge that clamps the end portion of the fiber-reinforced plastic wire is tightly pressed into the hollow of the terminal socket, thereby fixing (securing) the terminal socket to the end portion of the fiber-reinforced plastic wire via the wedge. The inner surface of the wedge may be non-slip.

[0017] A cylindrical buffer material is placed over the end of the fiber-reinforced plastic filament to be wedged. That is, the wedge is not directly inserted into the fiber-reinforced plastic filament, but the above-mentioned cylindrical buffer material is interposed between the filament and the wedge. The localized shear force generated when the wedge tightly grips the fiber-reinforced plastic filament from its periphery is buffered and dispersed by the above-mentioned cushioning cylindrical buffer material, making the fiber-reinforced plastic filament less likely to be damaged at the position of the terminal socket (position of the wedge), and ensuring high fixing efficiency (tensile strength).

[0018] The cylindrical cushioning material is made of a metal mesh sheet, a laminated sheet made of multiple metal mesh sheets, or a long, thin sheet made by forming a laminated sheet into a cylindrical shape. Even if the fiber-reinforced plastic filament is pulled strongly in the longitudinal direction, the frictional force generated by the fine irregularities on the entire front and back surfaces of the metal mesh sheet makes it difficult for the fiber-reinforced plastic filament to come out of the terminal socket (wedge). Of course, if the inner surface of the wedge is treated with a non-slip finish, this also contributes to increasing the frictional force and effectively prevents the filament from coming out of the wedge. The non-slip finish on the inner surface of the wedge can be a grooved or uneven surface, or metal particles fixed to the inner surface of the wedge.

[0019] The method for fixing the end of a fiber-reinforced plastic filament according to this invention involves preparing a tubular cushioning material made of a metal mesh sheet woven with thin metal wires, shaped so that it has a cylindrical hollow with a diameter that matches the diameter of the filament to be covered with the tubular cushioning material, covering the end portion of the fiber-reinforced plastic filament with the tubular cushioning material, clamping the part covered with the tubular cushioning material with a wedge, and wedging it into the terminal socket.

[0020] The present invention also provides the above-mentioned cylindrical cushioning material, which is made of a metal mesh sheet woven with fine metal wires and is shaped to have a cylindrical hollow with a diameter that corresponds to the diameter of the fiber-reinforced plastic filament that the cylindrical cushioning material will cover.

[0021] Metal mesh sheets are made by weaving thin metal wires (thin metal wires) into a fine mesh. The thin metal wires can be woven in any way, including plain weave, twill weave, tortoiseshell weave, tie rod weave, ton-cap weave, and other weaves. Thin wires made from any metal material, such as stainless steel, iron, aluminum, brass, copper, titanium, Inconel, and Hastelloy, can be used.

[0022] In this specification, "fine metal wire" refers to a metal wire with a diameter of 2.00 mm or less. If a metal wire with a diameter exceeding 2.00 mm is used, the strength of the metal mesh sheet or laminated sheet woven from multiple metal wires may become too high, making it difficult to form the metal mesh sheet or laminated sheet into a cylindrical cushioning material (cylindrical shape). By using a metal mesh sheet woven from multiple metal wires with a diameter of 2.00 mm or less, or a laminated sheet formed by stacking multiple layers of such a mesh sheet, it is easy to form the metal mesh sheet or laminated sheet into a cylindrical hollow with a diameter that matches the diameter of the fiber-reinforced plastic linear body.

[0023] The number of meshes (number of meshes per inch (25.4 mm)) of the metal mesh sheet can be any number. However, since the metal mesh sheet covers the fiber-reinforced plastic filaments, it is preferable that the mesh openings are not too large (too coarse).

[0024] When a fiber-reinforced plastic filament is formed by twisting together multiple fiber bundles, the surface of the filament has irregularities (or spiral grooves) extending helically in the longitudinal direction. When a cylindrical buffer material comes into direct contact with the filament and is squeezed with a strong force from the periphery, the thickness of the cylindrical buffer material becomes thinner at the convex portions on the surface of the filament and thicker at the concave portions (grooves). Because the cylindrical buffer material has cushioning properties as described above, it can conform to the irregularities on the surface of the filament (absorb or smooth the irregularities), thereby achieving a uniform cushioning effect across the entire surface of the filament.

[0025] Furthermore, according to this invention, a cylindrical buffer material is prepared in advance, in which the metal mesh sheet is shaped to have a cylindrical hollow with a diameter that matches the diameter of the linear object. Installation of the cylindrical buffer material is completed simply by covering the end of the fiber-reinforced plastic linear object with the cylindrical buffer material (by passing the linear object through the cylindrical hollow of the cylindrical buffer material) at the site. It takes only a short time to attach the terminal socket to the linear object.

[0026] When the cylindrical cushioning material is a thin, elongated sheet formed by stacking multiple layers of the above-mentioned metal mesh sheet and spirally wound, twisting the cylindrical cushioning material in the opposite direction to the spiral direction creates a spiral gap in the cylindrical cushioning material (a spiral gap opens between the side edges), thereby expanding the hollow diameter of the cylindrical cushioning material. Expanding the hollow diameter of the cylindrical cushioning material makes it easier to cover the end of a fiber-reinforced plastic filament with the cylindrical cushioning material. After covering the end of a fiber-reinforced plastic filament with the cylindrical cushioning material, twisting the cylindrical cushioning material in the spiral direction narrows the hollow diameter of the cylindrical cushioning material. Because the hollow diameter of the cylindrical cushioning material is the same as the diameter of the fiber-reinforced plastic filament (equal to or slightly larger than the diameter of the filament), the cylindrical cushioning material can tightly cover the surface of the fiber-reinforced plastic filament without loosening.

[0027] Both ends of the cylindrical buffer material may be fixed to the outer surface of the fiber-reinforced plastic wire using tape or the like. This will prevent the cylindrical buffer material from loosening. Of course, if a wedge is attached to the part where the cylindrical buffer material is covering and pushed into the hollow of the terminal socket, the cylindrical buffer material will be tightly clamped from all sides by the wedge, preventing the cylindrical buffer material from loosening.

[0028] By constructing the tubular cushioning material from the metal mesh sheet or laminated sheet having a length greater than the length of the wedge, or from an elongated sheet wound spirally over a length greater than the length of the wedge, the longitudinal length of the tubular cushioning material becomes equal to or greater than the longitudinal length of the wedge, and the area of ​​the fiber-reinforced plastic linear body that is clamped by the wedge can be covered by the tubular cushioning material over its entire length, effectively preventing the shear force from the wedge from being applied locally to the fiber-reinforced plastic linear body.

[0029] 12. An oblique view of an end fixing structure applied to the end of a carbon fiber reinforced plastic cable. An oblique view showing the manufacturing process of the end fixing structure. An enlarged, partially broken, oblique view of a tubular cushioning material (laminated sheet) in a flat state before being formed into a cylindrical shape. A layer structure of the tubular cushioning material of FIG. 3 is shown. An oblique view showing the manufacturing process of the end fixing structure. A cross-sectional view showing the manufacturing process of the end fixing structure. A cross-sectional view showing the manufacturing process of the end fixing structure. A cross-sectional view showing the manufacturing process of the end fixing structure. A layer structure of a tubular cushioning material of another embodiment. An oblique view of an end fixing structure of another embodiment. An oblique view showing the manufacturing process of an end fixing structure of another embodiment. An enlarged cross-sectional view of the tubular cushioning material taken along line XII-XII of FIG. 11. An enlarged cross-sectional view of a tubular cushioning material of another embodiment, equivalent to FIG. 12. A layer structure of a tubular cushioning material of another embodiment is shown.

[0030] Fig. 1 is a perspective view showing an embodiment in which a terminal fixing structure is applied to the end of a carbon fiber reinforced plastic (CFRP) cable (hereinafter referred to as a CFRP cable 1). Details of the terminal fixing structure shown in Fig. 1 will become clear by explaining the manufacturing process thereof, so the manufacturing process of the terminal fixing structure shown in Fig. 1 will be explained below with reference to Figs. 2 to 8.

[0031] The CFRP cable 1 is constructed by further twisting together multiple strands of wires with circular cross sections made from a composite material of carbon fiber and epoxy resin. The strands are formed into a circular cross section by twisting together multiple continuous carbon fibers and epoxy resin impregnated into the multiple carbon fibers. Figures 1 and 2 show a CFRP cable 1 with a 1x7 structure (a structure in which six strands are twisted around one central strand). The structure and diameter of the CFRP cable 1 can be designed as desired.

[0032] The cylindrical buffer material 2 of the first embodiment, which is placed around the end of the CFRP cable 1, is formed into a cylindrical shape from an elongated laminated sheet 2a, as shown enlarged in Figure 3. The cylindrical buffer material 2 is produced by spirally winding the elongated laminated sheet 2a around a bar (which may be the CFRP cable 1 itself) that is aligned with, or preferably has the same diameter as, the CFRP cable 1, thereby giving the elongated laminated sheet 2a a cylindrical shape with a cylindrical hollow having approximately the same diameter as the CFRP cable 1. For ease of understanding, Figure 3 exaggerates the thickness direction.

[0033] For example, if both ends of the tubular buffer material 2 are grasped with both hands and twisted (rotated) in the opposite direction to the spiral direction, spiral gaps are formed between adjacent elongated thin laminate sheets 2a (between their side ends), expanding the hollow diameter of the tubular buffer material 2. Conversely, if the tubular buffer material 2 is twisted along the spiral direction, the gaps between adjacent elongated thin laminate sheets 2a narrow, causing the side ends of the elongated thin laminate sheets 2a to come into contact with each other. The diameter of the tubular buffer material 2 when the side ends of the elongated thin laminate sheets 2a are in contact with each other is approximately equal to the diameter of the CFRP cable 1.

[0034] 3 and 4, the cylindrical buffer material 2 (elongated laminated sheet 2a) is made up of 16 SUS mesh sheets 2A-2P stacked together, from the first layer to the sixteenth layer. The innermost SUS mesh sheet 2A contacts the CFRP cable 1, and the outermost SUS mesh sheet 2P contacts the wedge 6 (described later). SUS refers to a special rust-resistant alloy steel containing 1.2% or less carbon and 10.5% or more chromium, with the total amount of elements other than iron not exceeding 50%. Other metals or alloys with equivalent strength to SUS, such as stainless steel, iron, aluminum, brass, copper, titanium, Inconel, Hastelloy, and alloys thereof, can also be used instead of SUS.

[0035] Referring to Figure 4, of the 16-layer SUS mesh sheets 2A to 2P, three layers (the innermost layer (layer 1), the middle layer (layer 9), and the outermost layer (layer 16)) of SUS mesh sheets 2A, 2I, and 2P are composed of a large number of SUS fine wires with a diameter of 0.29 mm. The remaining 13 layers (layers 2 to 8, layers 10 to 15) of SUS mesh sheets 2B to 2H and 2J to 2O are composed of a large number of SUS fine wires with a diameter of 0.12 mm. As shown schematically in Figure 3, SUS mesh sheets are woven wire meshes formed by weaving a large number of SUS fine wires. Generally, SUS mesh sheets 2A to 2P are made by plain weaving a large number of vertical SUS fine wires and a large number of horizontal SUS fine wires that run parallel to each other at small intervals in both the vertical and horizontal directions and intersect at right angles. Instead of plain weave, the SUS thin wire may be woven in a twill weave, tortoiseshell weave, tie rod weave, toncap weave, or other weave.

[0036] Returning to Figure 2, the tubular buffer material 2 is passed through the CFRP cable 1, and the end portion of the CFRP cable 1 is covered with the tubular buffer material 2. The length of the tubular buffer material 2 need only be longer than the longitudinal length of the wedge 6, which will be described later. The tubular buffer material 2 is placed over the outer surface of the CFRP cable 1 so as to wrap around the outer surface of the end portion of the CFRP cable 1. If the tubular buffer material 2 is loose and a spiral gap is created, the tubular buffer material 2 can be twisted in the spiral direction as described above. The CFRP cable 1 is covered with the tubular buffer material 2 without any slack (without any gaps).

[0037] Both ends of the cylindrical buffer material 2 may be simply fixed to the vicinity of the terminal end of the CFRP cable 1 using adhesive tape or the like. Adhesive tape or the like may be provided (fixed) in advance to one or both ends of the cylindrical buffer material 2, and the cylindrical buffer material 2 may be fixed to the vicinity of the terminal end of the CFRP cable 1 by wrapping the tape around the CFRP cable 1.

[0038] 1, 5, 6, and 7, a terminal socket (terminal sleeve) 5 and four wedges 6 are prepared. The terminal socket 5 is made of metal (e.g., stainless steel or iron), has a cylindrical outer shape, and has a roughly truncated cone-shaped hollow 5a inside. A thread groove 5d is formed on the outer surface near the end of the terminal socket 5. The terminal of the CFRP cable 1 covered with the cylindrical buffer material 2 is inserted into the hollow 5a of the terminal socket 5 from the small opening 5b side of the mouth of the terminal socket 5, and is then taken out from the large opening 5c ​​side.

[0039] Four wedges 6 are attached to the terminal portion of the CFRP cable 1, which is exposed outside the terminal socket 5 and covered with the cylindrical buffer material 2. All four wedges 6 have the same shape, and a shallow depression extending longitudinally is formed on the inner surface of each wedge 6. The depression has multiple grooves (convex / concave, blades, teeth) (not shown) extending perpendicular to the longitudinal direction of the wedge 6. The shape (including depth) of the depression is the same in the longitudinal direction. On the other hand, the thickness of the wedge 6 increases from the tip to the end. When the four wedges 6 are combined, they form a roughly truncated cone-shaped outer shape (Figure 5), which closely matches the shape of the hollow 5a of the terminal socket 5. The multiple grooves in the depression on the inner surface of the wedge 6 are formed to prevent slippage (to increase friction).

[0040] The depression on the inner surface of the wedge 6 is shallow, and the end portion of the CFRP cable 1 (the portion where the tubular buffer material 2 is located) does not entirely fit into the depression, and when the end portion of the CFRP cable 1 is clamped, a gap is created between adjacent wedges 6 in the longitudinal direction.

[0041] 6 and 7, the wedges 6 are pushed into the hollow 5a of the terminal socket 5 from the side of the large opening 5c ​​of the terminal socket 5. Referring to Fig. 8, when the wedges 6 are pushed even more firmly into the terminal socket 5, the four wedges 6 are pressed and tightened from all sides by the inner wall of the terminal socket 5. This fixes the terminal socket 5 to the end of the CFRP cable 1 via the wedges 6 and further via the above-mentioned cylindrical buffer material 2 (Fig. 1).

[0042] Fig. 9 shows the layer structure of cylindrical cushioning materials of other examples (second and third examples) corresponding to Fig. 4. The cylindrical cushioning materials of the second and third examples all have approximately the same thickness as the cylindrical cushioning material 2 of the first example (approximately 4.86 mm).

[0043] The cylindrical cushioning material of the second embodiment is composed of 18 layers of SUS mesh sheets 2A-2R, and all of the 1st to 18th layers of SUS mesh sheets 2A-2R are composed of a large number of fine SUS wires with a diameter of 0.12 mm. It can be manufactured from a single type of SUS mesh sheet. Because the diameter of the fine SUS wires in all of the SUS mesh sheets 2A-2R is small, the cylindrical cushioning material of the second embodiment is soft and easy to form into a cylindrical shape.

[0044] The cylindrical cushioning material of the third embodiment is composed of nine layers of SUS mesh sheets 2A to 2I, with the first, third to seventh, and ninth layers of SUS mesh sheets 2A, 2C to G, and 2I being composed of a large number of thin SUS wires with a diameter of 0.29 mm, and the remaining second and eighth layers of SUS mesh sheets 2B and 2H being composed of a large number of thin SUS wires with a diameter of 0.12 mm. By using SUS mesh sheets composed of thin SUS wires with a large wire diameter, the number of SUS mesh sheets that need to be stacked to achieve a specified thickness can be reduced, leading to cost reductions.

[0045] Table 1 shows the results of a constant load holding test for the end fixing structure (FIG. 1) using the cylindrical buffer material 2 (FIGS. 3 and 4) of the first embodiment.

[0046]

[0047] The CFRP cable 1 used was a 15.2 mm diameter cable made of a composite material of carbon fiber and epoxy resin, with a diameter of approximately 5.00 mm and a 1 x 7 structure (six twisted wires twisted around one twisted wire at the center).

[0048] One end of a CFRP cable 1 of a predetermined length was covered with a cylindrical buffer material 2 (as shown in Figures 3 and 4), and a terminal socket 5 was fixed using the terminal fixing structure using the wedge 6 described above, while the other end was fixed with a terminal fixing structure using a thermosetting resin. The terminal sockets on both ends were set in a tensile tester, and one of the terminal sockets 5 with the terminal fixing structure using a thermosetting resin was pulled with a constant load of 206 kN.

[0049] In the test, the surface temperature of the created terminal fixing structure (surface temperature of the terminal socket 5) was varied, and the terminal socket 5 was continuously pulled with a constant load of 206 kN for 72 hours. Multiple tests were conducted at each temperature, and those in which the CFRP cable 1 slipped out of the terminal socket 5 were evaluated as "failed," and those in which it did not slip out were evaluated as "passed."

[0050] As shown in Table 1, when the surface temperature of the terminal fixing structure was set to 20°C, 50°C, 70°C, 80°C, 85°C, 90°C, and 95°C, it was confirmed that the CFRP cable 1 did not come out of the terminal socket 5 in tests at 20°C to 90°C. On the other hand, when the surface temperature was set to 95°C, the CFRP cable 1 sometimes came out of the terminal socket 5. It was confirmed that high fixing performance can be maintained within the temperature range up to 90°C, even if high temperatures continue for a relatively long period of time.

[0051] 10 to 12 show a terminal fixing structure according to still another embodiment.

[0052] The terminal fixing structure described using Figures 1 to 9 uses a cylindrical cushioning material 2 formed by spirally winding an elongated laminated sheet 2a. The terminal fixing structure of another embodiment shown in Figures 10 to 12 differs in that the cylindrical cushioning material 8 is formed by rolling up a laminated sheet made of two overlapping square (rectangular) SUS mesh sheets. Detailed descriptions of the same components as those described using Figures 1 to 9 will be omitted.

[0053] 10 and 11 , a cylindrical buffer material 8 is placed around the end of the CFRP cable 1. The cylindrical buffer material 8 has a length that exceeds the length of the wedge 6. A terminal socket 5 is fixed to the end of the CFRP cable 1 via the wedge 6 and the cylindrical buffer material 8.

[0054] Figure 12 is an enlarged cross-sectional view of the cylindrical cushioning material 8 taken along line XII-XII in Figure 11. In Figure 12, the thickness of the SUS mesh sheets 8A and 8B that make up the cylindrical cushioning material 8 is shown in a highly exaggerated manner.

[0055] The cylindrical buffer material 8 is formed by rolling a rectangular laminated sheet made by laminating two SUS mesh sheets 8A and 8B in the width direction and shaping it into a cylindrical shape with a diameter that matches the diameter of the CFRP cable 1. The number of layers of the SUS mesh sheets 8A and 8B is arbitrary, and the degree of cushioning property of the cylindrical buffer material 8 can be controlled by increasing or decreasing the number of layers.

[0056] As shown in Fig. 13, a cylindrical cushioning material 9 may be formed by rolling and stacking one SUS mesh sheet 8A multiple times. Fig. 13 is a cross-sectional view, equivalent to Fig. 12, of a cylindrical cushioning material 9 formed by rolling and stacking one SUS mesh sheet 8A four times. The degree of cushioning properties of the cylindrical cushioning material 9 can be controlled by increasing or decreasing the number of turns (number of overlaps).

[0057] FIG. 14 shows the layer structure corresponding to FIG. 4 for each of the cylindrical cushioning material 8 (fourth embodiment) shown in FIG. 12, the cylindrical cushioning material 9 (fifth embodiment) shown in FIG. 13, and a cylindrical cushioning material (not shown) (sixth embodiment) formed into a cylindrical shape by rolling and stacking a single SUS mesh sheet 8A seven times.

[0058] When the above-mentioned constant load holding test was conducted on the terminal fixing structure using the cylindrical buffer material 9 (Figure 13) of the fifth embodiment (however, a CFRP cable 1 with a diameter of 7.9 mm was used and the load was 70 kN), it was confirmed that the CFRP cable 1 did not slip out of the terminal socket 5 when the surface temperature of the terminal fixing structure was set to 20°C and 50°C, and it was confirmed that high fixing performance could be achieved.

[0059] 1 CFRP cable 2, 8, 9 Cylindrical buffer material 2A to 2R, 8A, 8B SUS mesh sheet 2a Laminated sheet 5 Terminal socket 6 Wedge

Claims

1. A terminal fixing structure for a fiber-reinforced plastic wire, in which a cylindrical buffer material is placed over the end of the fiber-reinforced plastic wire, and the portion covered with the cylindrical buffer material is clamped and fixed by a wedge within a terminal socket, and the cylindrical buffer material is a metal mesh sheet woven with thin metal wires, shaped to have a cylindrical hollow with a diameter that matches the diameter of the wire.

2. The end fixing structure for a fiber-reinforced plastic wire as described in claim 1, wherein the cylindrical buffer material is composed of a laminated sheet made of multiple metal mesh sheets each having a length greater than the length of the wedge.

3. The terminal fixing structure according to claim 2, wherein the cylindrical cushioning material is the laminated sheet rolled up.

4. The end fixing structure for a fiber-reinforced plastic wire according to claim 1, wherein the cylindrical buffer material is formed by rolling and stacking the metal mesh sheet having a length greater than the length of the wedge multiple times.

5. The terminal fixing structure of a fiber-reinforced plastic wire as described in claim 1, wherein the cylindrical cushioning material is a long, thin laminated sheet made of multiple layers of the metal mesh sheet, which is wound spirally over a length that exceeds the length of the wedge.

6. The terminal fixing structure for a fiber-reinforced plastic filament according to claim 1, wherein the diameter of the fine metal wires constituting the metal mesh sheet is 2.00 mm or less.

7. The end fixing structure for a fiber-reinforced plastic filament according to claim 1, wherein the longitudinal length of the cylindrical buffer material is equal to or greater than the longitudinal length of the wedge.

8. A method for fixing the end of a fiber-reinforced plastic wire, comprising: preparing a cylindrical buffer material made of a metal mesh sheet woven with fine metal wires, shaped to have a cylindrical hollow with a diameter that matches the diameter of the wire to be covered with the cylindrical buffer material; covering the end of the fiber-reinforced plastic wire with the cylindrical buffer material; sandwiching the part covered with the cylindrical buffer material with a wedge and wedging it into a terminal socket.

9. A cylindrical cushioning material made of a metal mesh sheet woven with thin metal wires, shaped to have a cylindrical hollow with a diameter that matches the diameter of the fiber-reinforced plastic filament that the cylindrical cushioning material is to cover.

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