WO2020158242A1

WO2020158242A1 - Fiber structure and fiber-reinforced composite

Info

Publication number: WO2020158242A1
Application number: PCT/JP2019/049949
Authority: WO
Inventors: 神谷隆太
Original assignee: 株式会社豊田自動織機
Priority date: 2019-01-30
Filing date: 2019-12-19
Publication date: 2020-08-06
Also published as: JP2020122235A; JP7052751B2

Abstract

A fiber structure (20) of a first fiber-reinforced composite comprises a body (21) and a branch (22). The branch (22) comprises a branch boundary line (F1) that extends along a portion at which there is branching into a first formed part (23) and a second formed part (24), and comprises a first distal edge (23a), which extends along the distal end of the first formed part (23), and a second distal edge (24a) that extends along the distal end of the second formed part (24). The branch (22) has a shape such that the branch boundary line (F1), the first distal edge (23a), and the second distal edge (24a) are curved. In the fiber structure (20), the thread major axis of that weft thread (32), from among the weft threads (32) in the body (21), that is closest to the branch boundary line (F1) is a curved line parallel to the branch boundary line (F1).

Description

Fiber structure and fiber reinforced composite material

The present invention relates to a fiber structure having a branch portion and a fiber-reinforced composite material.

Fiber-reinforced composite material is used as a lightweight and high-strength material. The fiber-reinforced composite material is a structural component because the reinforcing fiber (reinforcing base material) is compounded in a matrix of resin, ceramics, etc. to improve mechanical properties (mechanical properties) compared to the matrix itself. preferable.

Further, as a fiber-reinforced composite material, there is a fiber-reinforced composite material having a curved portion such as an arc shape in a plan view, and the curved portion is branched into two in the thickness direction of the fiber-reinforced composite material (for example, refer to Patent Document 1). The three-dimensional fiber structure disclosed in Patent Document 1 has an I-shaped cross-sectional shape orthogonal to the longitudinal direction, and is curved along the longitudinal direction. The three-dimensional fiber structure has a fan-shaped plate-shaped portion and plate-shaped portions formed on both sides so as to form a right angle to the fan-shaped plate-shaped portion at the upper and lower ends of the fan-shaped plate-shaped portion. Each plate-shaped portion is curved and formed along the longitudinal direction of the fan-shaped plate-shaped portion.

In the fan-shaped plate portion, a yarn layer made of 0-degree arranged yarns arranged in an arc shape, a yarn layer made of 90-degree arranged yarns, and a yarn layer made of ±45-degree arranged yarns are joined by a thickness direction yarn. Is formed. The plate-shaped portion is formed by branching the laminated yarn group into two in the thickness direction so that the circular arc-shaped peripheral portion which is not joined by the thickness direction thread in the fan-shaped plate-shaped portion is perpendicular to the fan-shaped plate-shaped portion. And is formed by bending both sides in the thickness direction.

JP, 2005-97759, A

However, in Patent Document 1, the plate-shaped portions provided at the upper end and the lower end of the fan-shaped plate-shaped portion are formed by bifurcating arc-shaped peripheral portions that are not joined by the thickness direction thread into two in the thickness direction. ing. For this reason, the roots of the two branched yarn groups are curved, and the binding force (restraint force) of the thickness direction yarns is weak, and delamination of the laminated yarn group is likely to occur.

The present invention is to provide a fiber structure and a fiber reinforced composite material that can suppress delamination at a curved branch portion.

A fibrous structure for solving the above problems includes a first yarn layer made of a first yarn and a second yarn layer made of a second yarn intersecting with the first yarn, and the first yarn A multilayer woven fabric in which a layer and the second yarn layer are stacked, and the first yarn layer and the second yarn layer are bound by a binding yarn in a stacking direction in which the first yarn layer and the second yarn layer are stacked. Yes, all the yarn layers of the multilayer woven fabric are continuous with the main body along the main-axis direction of the first yarn and the main-axis part of the second yarn, A fibrous structure which is provided over the whole and has a branch portion obtained by branching a yarn layer of the multilayer fabric into a first forming portion on one end side in the laminating direction and a second forming portion on the other end side in the laminating direction. A branch boundary line extending along a portion of the branch portion that branches into the first forming portion and the second forming portion, wherein the branch portion has a curved shape of the branch boundary line, The gist of the present invention is that the yarn main axis of the second yarn closest to the branch boundary line of the second yarn of the main body portion is a parallel curve with respect to the line.

According to this, in the fibrous structure having the main body portion and the branch portion, the main body closest to the branch boundary line from the position where the first forming portion and the second forming portion branch, that is, the position of the curved branch boundary line. The part up to the second yarn is a part of the main body part where the restraint in the stacking direction is weak. However, by curving the second yarn and making it a parallel curve to the branch boundary line, the distance between the second yarn and the branch boundary line can be made constant along the yarn main axis direction of the first yarn, and the stacking direction The magnitude of the restraint force on the inner wall is eliminated, and delamination of the branched portion can be suppressed.

A fiber-reinforced composite material for solving the above problems is a fiber-reinforced composite material in which a fiber structure is used as a reinforcing base material, and the reinforcing base material is composited in a matrix, wherein the fiber structure is The gist is that it is the fiber structure described in 1.

According to this, in the fiber structure having the main body portion and the branch portion, the position of the main body portion closest to the branch boundary line from the position where the first forming portion and the second forming portion branch, that is, the position of the branch boundary line. Up to the second yarn, it is a portion of the main body portion where the restraint in the stacking direction is weak. However, by making the second yarn parallel to the branch boundary line, the distance between the second yarn and the branch boundary line can be made constant along the yarn main axis direction of the first yarn, and restrained in the stacking direction. The magnitude of the force is eliminated, and delamination at the branch can be suppressed. Therefore, also in the fiber-reinforced composite material, it is possible to eliminate the magnitude of the strength in the vicinity of the boundary between the main body portion and the branch portion.

According to the present invention, it is possible to suppress delamination at a curved branch portion.

The perspective view which shows a 1st fiber reinforced composite material and a 2nd fiber reinforced composite material. The top view which shows a board member. The partial perspective view which shows a branch part and a main-body part. The top view which shows a fiber structure. The figure which shows typically the fiber structure of a branch part and a main-body part. Explanatory drawing of the manufacturing process of a main-body part. Explanatory drawing of the manufacturing process of a branch part. The top view which shows the fiber structure of another example.

An embodiment in which a fiber structure and a fiber-reinforced composite material are embodied will be described below with reference to FIGS. 1 to 7.
As shown in FIG. 1 or FIG. 2, the plate member 10 is configured by connecting the first fiber-reinforced composite material 11 and the second fiber-reinforced composite material 110 by engagement of concavities and convexities. The first fiber-reinforced composite material 11 is formed by compounding the fiber structure 20 as a reinforcing base material in a matrix resin (shown by dot hatching). The second fiber reinforced composite material 110 is formed by compounding the fiber structure 120 as a reinforcing base material in a matrix resin (shown by dot hatching). The first fiber-reinforced composite material 11 and the second fiber-reinforced composite material 110 may be formed by compounding the

fiber structures

20 and 120 with matrix metal or ceramics instead of the matrix resin.

Each of the first fiber-reinforced composite material 11 and the second fiber-reinforced composite material 110 has a substantially rectangular shape in plan view and has a thickness. The first fiber-reinforced composite material 11 has a curved shape such that one edge in a plan view is recessed, and the first fiber-reinforced composite material 11 has a connection recess 12 along the curved one edge. The second fiber-reinforced composite material 110 has a curved shape such that one edge in a plan view bulges, and the second fiber-reinforced composite material 110 has a connecting convex portion 112 along the one curved edge. The first fiber-reinforced composite material 11 and the second fiber-reinforced composite material 110 are connected by fitting the connection convex portion 112 of the second fiber-reinforced composite material 110 into the connection concave portion 12 of the first fiber-reinforced composite material 11. The plate member 10 having a rectangular shape in plan view is configured. The plan view means that the first fiber-reinforced composite material 11 and the second fiber-reinforced composite material 110 are viewed from the outside along the thickness direction.

Next, the fiber structure 20 of the first fiber-reinforced composite material 11 will be described in detail.
The fiber structure 20 has a plate-shaped main body portion 21 and a branch portion 22 continuous with the main body portion 21. In the present embodiment, the direction in which the main body portion 21 and the branch portion 22 are continuous is referred to as the first direction X. The first direction X coincides with the extending direction of the pair of short edge portions of the fiber structure 20. Further, in the present embodiment, the direction orthogonal to the first direction X is the second direction Y. The second direction Y coincides with the extending direction of the long edge portion of the fiber structure 20.

As shown in FIG. 3, the branch portion 22 has a bifurcated shape in the thickness direction. The branch part 22 has a first forming part 23 located on one end side in the thickness direction of the fiber structure 20 and a second forming part 24 located on the other end side in the thickness direction.

The fibrous structure 20 has a branch boundary line F1 at a position where the facing surfaces of the first forming portion 23 and the second forming portion 24 intersect with each other, and the first forming portion 23 and the first forming portion 23 are separated from each other with the branch boundary line F1 as a boundary. The 2 forming part 24 is bifurcated. Further, the fibrous structure 20 has a ridge line F2 along a portion where the first forming portion 23 and the second forming portion 24 are bent with respect to the outer surface of the main body portion 21. The first forming portion 23 and the second forming portion 24 are bent from the ridge line F2 with respect to the main body portion 21. The branch boundary line F1 and the ridge line F2 are each curved in an arc shape in a plan view. The extending direction of the branch boundary line F1 and the ridge line F2 is the second direction Y (longitudinal direction) of the fiber structure 20. The distance between the branch boundary line F1 and the ridge line F2 along the first direction X is constant in the second direction Y.

As shown in FIG. 1 or FIG. 2, the first forming portion 23 has a first tip edge 23a which is curved in a plan view by extending in an arc shape, and the second forming portion 24 is extended in an arc shape. The second tip edge 24a is curved in a plan view. The first tip edge 23a and the second tip edge 24a are located at one end of the fibrous structure 20 in the first direction X. The fiber structure 20 has a base end edge 20a at the other end in the first direction X.

As shown in FIG. 4, the first tip edge 23a and the second tip edge 24a are parallel curves to the branch boundary line F1 and the ridge line F2 in a plan view. That is, in plan view, the first tip edge 23a and the second tip edge 24a share a normal line of the same length at all points on the branch boundary line F1 or the ridge line F2, and the branch boundary line F1 or The distance between the ridgeline F2 and the first tip edge 23a is constant, and the distance between the branch boundary line F1 or the ridgeline F2 and the second tip edge 24a is constant in the second direction Y. In the present embodiment, the distance between the branch boundary line F1 or the ridgeline F2 and the first tip edge 23a and the distance between the branch boundary line F1 or the ridgeline F2 and the second tip edge 24a are constant in the second direction Y. The term “included” includes the manufacturing tolerance and the manufacturing error of the fiber structure 20 and is not limited to the same distance. Each of the first forming portion 23 and the first forming portion 23 has a fan-shaped plate shape in plan view.

The fiber structure 20 is a multi-layer woven fabric. In the fiber structure 20, the warp yarns 31 as a plurality of first yarns arranged in parallel to each other in a linearly extending direction of the yarn main axis L1 and a state in which the yarn main axis direction L2 extends in a direction intersecting the warp yarns 31. It is a woven fabric having a plurality of weft yarns 32 as the second yarns. The yarn main axis direction L1 of the warp yarn 31 extends linearly in the first direction X of the fiber structure 20, and the yarn main axis direction L2 of the weft yarn 32 extends linearly or curvedly in the second direction Y of the fiber structure 20. ..

The warp yarn 31 and the weft yarn 32 are fiber bundles formed by bundling reinforcing fibers. As the reinforcing fibers, organic fibers or inorganic fibers may be used, or different types of organic fibers, different types of inorganic fibers, or mixed fiber obtained by mixing organic fibers and inorganic fibers may be used. Examples of the type of organic fiber include aramid fiber, poly-p-phenylenebenzobisoxazole fiber, and ultrahigh molecular weight polyethylene fiber, and examples of the type of inorganic fiber include carbon fiber, glass fiber, ceramic fiber and the like.

As shown in FIG. 5, the fiber structure 20 is configured by laminating a plurality of yarn layers. The stacking direction of the yarn layers is the stacking direction Z of the fiber structure 20. The stacking direction Z coincides with the thickness direction of the first fiber-reinforced composite material 11. Note that, in FIG. 5, in order to make it easier to understand the positional relationship between the warp yarns 31 and the weft yarns 32, the adjacent warp yarns 31 and the weft yarns 32 are illustrated as separated from each other, but in reality, the end portions of the adjacent warp yarns 31 are adjacent to each other. The ends of the weft yarns 32 are arranged so as to overlap each other.

The main body 21 of the fiber structure 20 has a plurality of warp layers in which a plurality of warp yarns 31 are formed side by side in the second direction Y. The warp layers include a first warp layer 41 and a second warp layer 42 arranged below the first warp layer 41 in the laminating direction Z. The first warp layer 41 and the second warp layer 42 form a first yarn layer.

Further, the main body 21 of the fiber structure 20 has a plurality of weft layers in which a plurality of wefts 32 are formed side by side in the first direction X. As the weft layers, a first weft layer 51, a second weft layer 52 arranged below the first weft layer 51 in the laminating direction Z, and a second weft layer 52 arranged below the second weft layer 52 in the laminating direction Z. The third weft layer 53 and the fourth weft layer 54 arranged below the third weft layer 53 in the stacking direction Z are included. The first weft layer 51, the second weft layer 52, the third weft layer 53, and the fourth weft layer 54 form a second yarn layer.

The main body portion 21 of the fiber structure 20 includes a first weft layer 51, a first warp layer 41, a second weft layer 52, a third weft layer 53, a second weft layer 53, a second weft layer 53, and a second weft layer 53 from one end to the other end (from top to bottom) in the stacking direction Z. The warp layer 42 and the fourth weft layer 54 are laminated in this order. The first weft layer 51, the first warp layer 41, the second weft layer 52, the third weft layer 53, the second warp layer 42, and the fourth weft layer 54, that is, all the yarn layers of the main body portion 21, are composed of a plurality of layers. It is restrained in the stacking direction Z by the restraint yarn 25.

The plurality of binding threads 25 are arranged in the second direction Y. Each restraint yarn 25 is for holding the shape of the fibrous structure 20, and is a fiber bundle of reinforcing fibers. As the reinforcing fibers, organic fibers or inorganic fibers may be used, or different types of organic fibers, different types of inorganic fibers, or mixed fiber obtained by mixing organic fibers and inorganic fibers may be used. The plurality of constraining yarns 25 are arranged substantially parallel to the warp yarns 31 and folded back through the outer surface of the weft yarns 32 of the uppermost first weft yarn layer 51 constituting the main body portion 21 of the fibrous structure 20. It is arranged. Further, each of the restraint yarns 25 penetrates the main body portion 21 in the stacking direction Z and is arranged so as to be folded back through the outer surface of the weft yarn 32 of the fourth weft layer 54 which is the lowermost layer. Therefore, the restraint yarn 25 is engaged with the weft yarns 32 of the first weft layer 51 and the fourth weft layer 54 at both ends in the stacking direction Z.

Regarding the binding yarns 25 adjacent to each other in the second direction Y, the positions of the weft yarns 32 folded back at the first weft layer 51 or the fourth weft layer 54 are displaced in the first direction X. Then, the restraint yarn 25 is engaged with each weft yarn 32, whereby the first to fourth weft layers 51 to 54 are restrained in the laminating direction Z, and the first weft layer 51 and the second weft layer adjacent to each other in the laminating direction Z. The first warp layer 41 is constrained between 52 and the second warp layer 42 is constrained between the third weft layer 53 and the fourth weft layer 54.

In the branch portion 22, in the first forming portion 23, the first weft layer 51, the first warp layer 41, and the second weft layer 52 are constrained in the laminating direction Z by the constraining yarn 25. The restraint yarn 25 is engaged with the weft yarns 32 of the first weft layer 51 and the second weft layer 52 at both ends of the first forming portion 23 in the stacking direction Z. In the second forming portion 24, the third weft layer 53, the second warp layer 42, and the fourth weft layer 54 are constrained in the laminating direction Z by the constraining yarn 25. The restraint yarn 25 is engaged with the weft yarns 32 of the third weft layer 53 and the fourth weft layer 54 at both ends of the second forming portion 24 in the stacking direction Z. The first forming portion 23 and the second forming portion 24 are not restrained in the stacking direction Z by the restraining yarn 25. Therefore, in the branching portion 22, the first forming portion 23 is located on one end side in the laminating direction Z in the multilayer fabric, and the second forming portion 24 is located on the other end side in the laminating direction Z in the multilayer fabric.

As shown in FIG. 4, in the fiber structure 20, the yarn main axis direction L2 of the weft yarn 32 extends linearly at the base end edge 20a of the fiber structure 20. Then, among the weft threads 32, from the weft thread 32 located at the base end edge 20a to the weft thread 32 reaching just before the branch boundary line F1, the yarn main axis direction L2 extends linearly in the second direction Y. Then, of the wefts 32, from the weft 32 closer to the base end edge 20a than the branch boundary line F1 to the wefts 32 extending from the first tip edge 23a and the second tip edge 24a, the yarn main axis direction L2 is all curved with the same curvature. doing.

As shown in FIG. 5, in the fiber structure 20 having the above configuration, the closest weft yarn 32 along the first direction X to the branch boundary line F1 of the branch portion 22 is set as the shortest weft yarn 32a. In the present embodiment, the shortest wefts 32a are all the wefts 32 in the stacking direction Z that are adjacent to the branch boundary line F1 along the first direction X. Therefore, the shortest weft 32a exists in the first weft layer 51, the second weft layer 52, the third weft layer 53, and the fourth weft layer 54.

All the shortest wefts 32a are parallel curves to the branch boundary line F1. That is, the shortest weft 32a shares a normal line of the same length at all points of the branch boundary line F1, and the distance between the branch boundary line F1 and the shortest weft thread 32a is constant in the second direction Y. In the present embodiment, the fact that the distance between the branch boundary line F1 and the shortest weft 32a is constant in the second direction Y includes the manufacturing tolerance and the manufacturing error of the fiber structure 20 and is the same. Not limited.

The restraining yarns 25 intersect at the positions where the first forming portion 23 and the second forming portion 24 branch, and the restraining yarns 25 are the shortest wefts 32a adjacent to the intersecting positions in the first direction X. Of these, the main body portion 21 is restrained in the stacking direction Z by engaging with the shortest wefts 32a of the first weft layer 51 and the fourth weft layer 54.

Of the restraint yarns 25 restraining the first forming portion 23, the restraint yarns 25 engaged with the weft yarns 32 of the second weft layer 52 adjacent to the shortest weft yarns 32a are engaged with the shortest weft yarns 32a of the first weft layer 51. ing. Further, among the restraint yarns 25 for restraining the first forming portion 23, the restraint yarns 25 engaged with the weft yarns 32 of the first weft layer 51 adjacent to the shortest weft yarns 32a are engaged with the shortest weft yarn 32a of the fourth weft layer 54. It fits.

Of the restraint yarns 25 for restraining the second forming portion 24, the restraint yarns 25 engaged with the weft yarns 32 of the fourth weft layer 54 adjacent to the shortest weft yarns 32a are engaged with the shortest weft yarns 32a of the first weft layer 51. It fits. Of the restraint yarns 25 for restraining the second forming portion 24, the restraint yarns 25 engaged with the weft yarns 32 of the third weft layer 53 adjacent to the shortest weft yarns 32a are engaged with the shortest weft yarns 32a of the fourth weft layer 54. ing.

Therefore, from the position where the first forming portion 23 and the second forming portion 24 intersect to the portion where the shortest weft 32a is constrained in the stacking direction Z, the wefts 32 other than the shortest weft 32a of the main body portion 21 are the constraining yarns 25. The restraint force of the restraint thread 25 is smaller than that of the restrained portion. The larger the distance from the branch boundary line F1 along the first direction X to the shortest weft 32a, the weaker the binding force of the binding yarn 25 on the main body portion 21 becomes. When the distance from the branch boundary line F1 along the first direction X to the shortest weft 32a is large or small, the binding force of the binding yarn 25 is large or small. However, in the present embodiment, the shortest weft 32a is curved to form a parallel curve with respect to the branch boundary line F1, so that the distance from the branch boundary line F1 along the first direction X to each shortest weft thread 32a is set to the second direction. Since all are the same along Y, the difference in the restraint force by the restraint yarn 25 is eliminated in the vicinity of the boundary between the branch portion 22 and the main body portion 21.

Next, a method for manufacturing the fiber structure 20 will be described.
As shown in FIG. 6 or 7, the weaving machine for weaving the fiber structure 20 includes a plurality of pairs (only one pair is shown in FIGS. 6 and 7) of heald frames 61, a reed 62a or a modified reed 62b, and a take-up mechanism 63. The weaving machine is provided with a weft inserting mechanism 64 and a warp supplying mechanism 65. The pair of heddle frames 61 each include a heald corresponding to each warp yarn 31, and are alternately moved up and down via a heddle frame drive mechanism (not shown) to open the warp yarns 31. The warp yarns 31 are respectively pulled out from a creel or a beam (not shown) while applying a predetermined tension.

The reed 62a or the modified reed 62b is arranged between the heald frame 61 and the take-up mechanism 63. The reeds 62a or the modified reeds 62b have a retreat position in which each warp thread 31 passes through the reed wing and is retracted rearward from the weft insertion mechanism 64 along the warp threads 31 and a weft thread 32 that is wefted by the weft insertion mechanism 64. It moves back and forth between the forward position where it is driven into the front F. The linear reed 62a is used when beating the main body 21 so that the weft thread 32 extends linearly in the yarn main axis direction L2. The deformed reed 62b that is curved in an arc shape is used when beating the part of the main body 21 and the branching portion 22 so that the weft yarn 32 is curved in the yarn main axis direction L2.

The weft inserting mechanism 64 inserts the weft yarn 32 supplied from the weft yarn supplying bobbin 66 into the opened warp yarn 31 between the reed 62a or the deformed reed 62b retracted to the retracted position and the cloth fell F. A rapier mechanism is used as the weft inserting mechanism 64, and a cutter 64a is disposed on the front surface thereof. The cutter 64a cuts the rear end portion of the weft yarn 32 that has been weft-inserted, every time weft-inserting. The take-up mechanism 63 is disposed immediately in front of the cloth fell F and takes up the woven fiber structure 20.

When manufacturing the fibrous structure 20, first, the main body portion 21 is formed.
As shown in FIG. 6, the end portion of the warp yarn 31 is fixed to the take-up mechanism 63, and the weft insertion mechanism 64 inserts the weft yarn 32 while the warp yarn 63 is taken up (winded) from the warp yarn supply mechanism 65. .. At this time, the warp yarns 31 are taken up by the take-up mechanism 63 so that the yarn main axis direction L1 extends linearly, and the weft yarns 32 are inserted so that the yarn main axis direction L2 is orthogonal to the yarn main axis direction L1. To be done. Then, the weft yarn 32 that has been weft-inserted from the weft-inserting mechanism 64 is beaten by the reed 62a so that the yarn main axis direction L2 extends linearly.

Then, when the reed is pushed to the branch portion 22 side of the main body portion 21, the reed 62a is replaced with the deformed reed 62b. Thereafter, as shown in FIG. 7, the weft insertion mechanism 64 inserts the weft yarn 32 while the warp yarn feeding mechanism 65 takes up (winds) the warp yarn 31 by the take-up mechanism 63, and the weft-inserted weft yarn 32 is deformed. It is beaten by 62b so that the yarn main axis direction L2 is curved.

Then, the first weft layer 51, the first warp layer 41, the second weft layer 52, the third weft layer 53, the second warp layer 42, and the fourth weft layer 54 are formed, and these are bound by the binding yarn 25. The body portion 21 is constrained to be formed.

Next, the branch part 22 is manufactured. At this time, a jig not shown is used. The first forming portion 23 and the second forming portion 24 are woven with the jig interposed therebetween. With the jig arranged, the warp yarns 31 are arranged on both sides in the thickness direction of the jig, and the weft yarn 32 inserted from the weft supply bobbin 66 is beaten by the deformed reed 62b, It is curved to a predetermined curvature. Although not shown, the binding yarn 25 is also woven by the loom. Then, the first forming portion 23 and the second forming portion 24 are woven with the jig interposed therebetween. Then, after the branch portion 22 is formed, the jig is removed.

As a result, the third weft layer 53, the second warp layer 42, and the fourth weft layer 54 are formed while forming the first weft layer 51, the first warp layer 41, and the second weft layer 52, and the constraining yarn is formed. These are constrained by 25 to form the first forming portion 23 and the second forming portion 24.

The first forming portion 23 having a constant distance between the branch boundary line F1 and the first tip edge 23a along the first direction X is formed, and the distance between the branch boundary line F1 and the second tip edge 24a is constant. The second forming portion 24 is formed. Further, the branch portion 22 and the main body portion 21 are formed, and the fiber structure 20 is formed.

As shown in FIG. 1, the fibrous structure 20 configured as described above has the fibrous structure 20 in the connection recess 12 formed between the first forming portion 23 and the second forming portion 24 of the fibrous structure 20. The connecting convex portion 112 formed on 120 is fitted to form a rectangular plate. Then, when the fiber structure 20 and the fiber structure 120 are impregnated with a matrix resin, the first fiber-reinforced composite material 11 and the second fiber using the fiber structure 20 and the fiber structure 120 as a reinforcing base material and a resin as a matrix. The reinforced composite material 110 is manufactured and the rectangular flat plate member 10 is formed.

According to the above embodiment, the following effects can be obtained.
(1) In the fiber structure 20, each shortest weft thread 32a of the main body portion 21 is a parallel curve with respect to the branch boundary line F1 located at the root of the branch portion 22. Therefore, the distance from the branch boundary line F1 to each shortest weft thread 32a can be made constant over the entire second direction Y, and the binding force of the binding thread 25 near the branch boundary line F1 can be eliminated. Therefore, delamination can be suppressed near the boundary between the main body portion 21 and the branch portion 22. Even in the first fiber-reinforced composite material 11 using the fiber structure 20 as a reinforcing base material, it is possible to eliminate the magnitude of strength near the boundary between the main body portion 21 and the branch portion 22.

The above embodiment may be modified as follows.
○ In the main body portion 21, the weft yarns 32 are arranged to extend linearly in the yarn main axis direction L2 except for a part near the branch portion 22, but as shown in FIG. The main axis direction L2 may be curved to form a parallel curve with respect to the branch boundary line F1.

The first yarn may be the weft yarn 32 and the second yarn may be the warp yarn 31.
The fibrous structure 20 may have a configuration in which branch portions 22 are provided on both sides of the main body portion 21 along the first direction X.

The number of yarn layers forming the branching portion 22 and the main body portion 21 may be changed.
The fibrous structure 20 of the first fiber-reinforced composite material 11 may include the branch portions 22 at a plurality of edges of the fibrous structure 20.

〇 In the fibrous structure 20, if the shortest weft 32a and the branch boundary line F1 are parallel curves, the wefts 32 other than the shortest weft 32a may have a curvature that is not a parallel curve to the branch boundary line F1.

〇 In the embodiment, the shortest weft 32a forming a parallel curve to the branch boundary line F1 is provided in the first to fourth weft layers 51 to 54, and the shortest weft 32a is provided in the entire laminating direction Z of the fibrous structure 20. It is not limited to this. The shortest weft 32a that is a curved line parallel to the branch boundary line F1 may be provided only in the first weft layer 51 and the fourth weft layer 54, or only in the second weft layer 52 and the third weft layer 53. It may be.

F1 Branching boundary line L1 Yarn principal axis direction of first yarn L2 Yarn principal axis direction of second yarn 11 First fiber-reinforced composite material 13 Warp yarn as first yarn 14 Weft yarn as second yarn 20 Fiber structure 21 Main body portion 22 Branching Part 23 First forming part 24 Second forming part 25 Restraining yarn 41 First warp layer as first yarn layer 42 Second warp layer as first yarn layer 51 First weft layer as second yarn layer 52 Second Second weft layer as yarn layer 53 Third weft layer as second yarn layer 54 Fourth weft layer as second yarn layer

Claims

A first yarn layer made of a first yarn and a second yarn layer made of a second yarn that intersects the first yarn, and the first yarn layer and the second yarn layer are stacked, and A multi-layer woven fabric in which the first yarn layer and the second yarn layer are restrained by restraining yarns in a laminating direction in which one yarn layer and the second yarn layer are stacked,
A body portion in which all the yarn layers of the multi-layered fabric are restrained by the restraining yarns;
The first yarn is continuous with the main body along the main axis of the first yarn and is provided over the entire main axis of the second yarn. A fibrous structure having a forming part and a branching part branched to a second forming part on the other end side in the stacking direction,
In the branch portion, a branch boundary line extending along a portion that branches into the first forming portion and the second forming portion,
The branch portion has a shape in which the branch boundary line is curved,
A fiber structure in which a yarn main axis of the second yarn closest to the branch boundary line of the second yarns of the main body portion is a parallel curve with respect to the branch boundary line.
The fiber structure is a reinforcing base material, and the reinforcing base material is a fiber-reinforced composite material compounded in a matrix, wherein the fiber structure is the fiber structure according to claim 1. Fiber reinforced composite material.