JP7322588B2 - Fiber structures and fiber reinforced composites - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fiber structure and a fiber reinforced composite material provided with a gap filling member that fills a gap.

Fiber-reinforced composite materials are used as lightweight and high-strength materials. A fiber-reinforced composite material is preferable as a structural component because a fiber structure made of reinforcing fibers is compounded in a matrix material such as a resin or metal, thereby improving mechanical properties compared to the matrix material itself. In particular, it is preferable to use a resin as the matrix material because the weight of the structural parts can be reduced.

As this type of fiber-reinforced composite material, for example, there are those formed in an I-shape or a T-shape (see, for example, Patent Document 1). The reinforcing substrate of the stiffener disclosed in US Pat. A pair of C-channels each include a web portion and a flange provided at each end of the web portion and extending in opposite directions on the pair of C-channels.

A pair of web portions are joined to form a web of reinforcement. In the reinforcing substrate, a cap is connected to the outside of the pair of flanges on one end side of the web, and a base is connected to the outside of the pair of flanges on the other end side of the web. Thus, the reinforcing matrix is composed of a pair of C-channels, a cap and a base.

Between the pair of C-channel flanges and the cap, and between the pair of C-channel flanges and the base, gaps having a triangular cross-section are defined in the reinforcing base material. A reinforcing filler having a triangular cross-section that is substantially the same as the gap is filled. A composite tape, a cloth member, or the like is employed as the reinforcing filler. Also, the surface of the C-channel surrounding the gap is covered with a fabric layer. Further, in the gap, an adhesive layer is provided inside the cloth layer, and the reinforcing filler is wrapped in the adhesive layer. The cloth layer, the adhesive layer, and the reinforcing filler reinforce the periphery of the gap in the reinforcing member.

Japanese Patent Application Publication No. 2011-520690

However, in Patent Document 1, in order to reinforce the periphery of the gap in the reinforcing material, a cloth layer, an adhesive layer, and a reinforcing filler are required, and the cloth layer, the adhesive layer, and the reinforcing filler are required. There is a problem that the work for providing the is troublesome.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fiber structure and a fiber-reinforced composite material that facilitate the work necessary to reinforce the periphery of gaps in the fiber-reinforced composite material.

A fiber structure for solving the above problems is a fiber structure of a fiber-reinforced composite material formed by impregnating the fiber structure with a matrix material, and is a main body portion in which a plurality of fiber layers of reinforcing fibers are laminated. A first fiber base material having a branched portion obtained by bifurcating the main body portion along the stacking direction of the fiber layer, and a first fiber base material covering the branched portion and integrated with the first fiber base material and a gap-filling member filled in a gap defined by the branched portion and the second fiber base material, wherein the gap-filling member is a twisted yarn or a non-twisted yarn of discontinuous fibers. wherein the length of the discontinuous fibers is oriented so as to extend in the axial direction of the gap filling member, the length of the discontinuous fibers is shorter than the axial length of the gap filling member, and the gap is filled with The gist is that a plurality of the gap filling members are filled .

A fiber-reinforced composite material for solving the above problems is a fiber-reinforced composite material composed of a fiber structure impregnated with a matrix material, and the fiber structure is any one of claims 1 to 4. The gist is that it is the fiber structure according to claim 1.

In each configuration, the gap-filling member is added to the branched portion of the first fiber base material before the first fiber base material and the second fiber base material are integrated, that is, before the branched part is covered with the second fiber base material. placed in Thereafter, by covering the branched portion with the second fiber base material, a gap is defined and the gap is filled with the gap filling member.

Since the gap filling member is a fiber bundle of discontinuous fibers, it has a string shape. For this reason, for example, compared to the case where a nonwoven fabric is arranged at the bifurcation, it is easier to handle, and unlike the nonwoven fabric, it is not necessary to shape the bifurcation into the shape of the bifurcation. is.

In a fiber-reinforced composite material produced by impregnating a fiber structure with a matrix material, the periphery of the gap is reinforced with discontinuous fibers. By simply adjusting the number of gap filling members that fill the gap, the amount of discontinuous fibers that fill the gap can be adjusted to an amount suitable for reinforcement. For this reason, for example, in order to reinforce the periphery of the gap, compared to the case where a plurality of types of reinforcing materials are prepared or a reinforcing member that follows the shape of the gap is manufactured, the gap in the fiber reinforced composite material is reduced. The work necessary to reinforce the perimeter can be easily performed.

Regarding the fiber structure, the second fiber base material has a plurality of laminated fiber layers of reinforcing fibers, and the stacking direction of the fiber layers in the second fiber base material and the stacking direction of the fiber layers in the main body part. , the branched portion extends continuously along the depth direction, and the gap extends throughout the fiber structure in the depth direction, and extends in the axial direction of the gap filling member. may be 60% or more of the dimension of the gap in the depth direction.

According to this, the discontinuous fibers of the gap filling member are oriented so as to extend in the depth direction of the main body. Therefore, in the fiber-reinforced composite material manufactured by impregnating the matrix material into the fiber structure, the strength in the depth direction can be ensured by the gap filling member.

Regarding the fiber structure, even if the fiber volume content ratio indicating the amount of the discontinuous fibers per unit volume of the gap is less than or equal to the fiber volume content ratio indicating the amount of the reinforcing fibers per unit volume in the main body portion good.

According to this, the ratio of the discontinuous fibers of the gap filling member in the gap does not become too high, and the dense overlapping of the discontinuous fibers is suppressed. As a result, in the gap filling member arranged in the gap, it is easy to impregnate the matrix material between the discontinuous fibers.

Regarding the fiber structure, the twisted or non-twisted yarn of discontinuous fibers may have a core yarn made of continuous fibers extending in the entire axial direction of the gap filling member.

According to this, it is easy to maintain the straight shape of the gap filling member by the core yarn, and it is easy to arrange the gap filling member at the bifurcation.

ADVANTAGE OF THE INVENTION According to this invention, the operation|work required to reinforce the circumference|surroundings of the clearance gap in a fiber-reinforced composite material can be performed simply.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the fiber reinforced composite material of embodiment. FIG. 2 is a partial cross-sectional view showing a fiber structure; The figure which shows a clearance gap typically. The schematic diagram which shows a gap filling member. The figure which shows typically the state which arrange|positions a gap filling member. The figure which shows the state which manufactures a fiber structure. The schematic diagram which shows another example of a gap filling member.

An embodiment embodying a fiber structure and a fiber-reinforced composite material will be described below with reference to FIGS. 1 to 6. FIG.
As shown in FIG. 1, a fiber-reinforced composite material 10 is formed by impregnating a fiber structure 11 having a T-shaped cross section with a matrix resin Ma, which is an example of a matrix material, and curing the material. The fiber structure 11 has a rectangular plate-like body portion 11a and a flange 11b orthogonal to the body portion 11a. The fiber structure 11 is defined between the first fiber base material 12 having a T-shaped cross section, the flat second fiber base material 20, and the first fiber base material 12 and the second fiber base material 20. and a gap filling member 30 that fills the gap S.

The first fiber base material 12 is formed by joining two L-shaped fiber bodies 13 to have a T-shaped cross section. The L-shaped fiber body 13 is composed of warp yarns T, weft yarns R, and interlayer binding yarns (not shown). The warp yarn T and the weft yarn R are formed of continuous 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 fibers obtained by mixing organic fibers and inorganic fibers may be used. Examples of organic fibers include acrylic fibers, nylon fibers, polyester fibers, aramid fibers, poly-p-phenylenebenzobisoxazole fibers, ultra-high molecular weight polyethylene fibers, etc. Examples of inorganic fibers include carbon fibers, glass fibers, and ceramic fibers. etc. In this embodiment, the warp threads T and the weft threads R are made of carbon fiber.

The L-shaped fibrous body 13 is a multi-layer fabric formed by binding a plurality of warp layers 13a as fiber layers and a plurality of weft layers 13b as fiber layers in the lamination direction Z with interlayer binding yarns (not shown). The warp layer 13a is formed by arranging a plurality of warps T in parallel, and the weft layer 13b is formed by arranging a plurality of wefts R in parallel. A plurality of warp threads T and weft threads R are orthogonal to each other. Note that the L-shaped fiber body 13 may be constructed by laminating single-layer fabrics formed by plain weaving, twill weaving, or satin weaving, and binding the laminates with interlayer binding yarns. That is, the L-shaped fibrous body 13 may be woven in any configuration.

The L-shaped fiber body 13 is formed by bending a flat multi-layered fabric into an L-shape. The “L shape” of the L-shaped fibrous body 13 means that the cross section of the L-shaped fibrous body 13 along the stacking direction Z is L-shaped. The L-shaped fiber body 13 has a flat plate-like base portion 15 , a flat plate-like flange forming portion 16 orthogonal to the base portion 15 , and a connecting portion 17 connecting the base portion 15 and the flange forming portion 16 . In the L-shaped fiber body 13 , the yarn main axis of the weft R extends in a direction connecting the base portion 15 and the flange forming portion 16 . On the other hand, the yarn main axis of the warp T extends in a direction orthogonal to the yarn main axis of the weft R.

As shown in FIG. 2, the base 15 has a first base surface 15a facing the base 15 of the other L-shaped fiber body 13 on one end surface in the stacking direction Z, and a second base surface 15a on the other end surface in the stacking direction Z. It has a surface 15b. The flange forming part 16 has a first flange surface 16a facing the second fiber base material 20 on one end surface in the stacking direction Z, and a second flange surface 16b on the other end surface in the stacking direction Z.

The connecting portion 17 is a portion sandwiched between the flat plate-like base portion 15 and the flange forming portion 16, and has a substantially fan-shaped cross section along the stacking direction Z. As shown in FIG. The connection portion 17 includes a first curved surface 17a located between the first base surface 15a of the base portion 15 and the first flange surface 16a of the flange forming portion 16, and has a flange structure with the second base surface 15b of the base portion 15. It comprises a second curved surface 17b located between the second flange surface 16b of the portion 16. As shown in FIG. The first curved surface 17a and the second curved surface 17b have the same curvature. The arc length of the first curved surface 17a is longer than the arc length of the second curved surface 17b in the cross section along the stacking direction Z.

In the first fiber base material 12 , the main body portion 11 a is formed from the base portions 15 of the two L-shaped fiber bodies 13 . A plurality of warp layers 13a and a plurality of weft layers 13b are laminated in the lamination direction Z in the main body portion 11a. In addition, the first fiber base material 12 includes a branched portion 18 sandwiched between the first curved surface 17a of one L-shaped fibrous body 13 and the first curved surface 17a of the other L-shaped fibrous body 13 . The branched portions 18 are recessed from the first flange surfaces 16a of the pair of L-shaped fiber bodies 13. As shown in FIG.

As shown in FIG. 1, the second fiber base material 20 is flat. The second fiber base material 20 is composed of warp yarns T, weft yarns R, and interlayer binding yarns (not shown). Note that the warp threads T and the weft threads R are made 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 fibers obtained by mixing organic fibers and inorganic fibers may be used. Examples of organic fibers include acrylic fibers, nylon fibers, polyester fibers, aramid fibers, poly-p-phenylenebenzobisoxazole fibers, ultra-high molecular weight polyethylene fibers, etc. Examples of inorganic fibers include carbon fibers, glass fibers, and ceramic fibers. etc. In this embodiment, the warp threads T and the weft threads R are made of carbon fiber.

The second fiber base material 20 is a multi-layer fabric formed by binding a plurality of warp layers 20a as fiber layers and a plurality of weft layers 20b as fiber layers in the lamination direction Z with interlayer binding yarns (not shown). . The warp layer 20a is formed by arranging a plurality of warps T in parallel, and the weft layer 20b is formed by arranging a plurality of wefts R in parallel. A plurality of warp threads T and weft threads R are orthogonal to each other. The second fiber base material 20 may be formed by laminating single-layer fabrics formed by plain weaving, twill weaving, or satin weaving, and binding the laminate with interlayer binding yarns. That is, the weave configuration of the second fiber base material 20 may be of any type. In the fiber structure 11, the direction perpendicular to the stacking direction Z of the warp layer 13a and the weft layer 13b in the main body portion 11a and the stacking direction Z of the warp layer 20a and the weft layer 20b in the second fiber base material 20 is the depth direction. Let Y. The above-described branched portion 18 extends continuously along the depth direction Y, and exists over the entire depth direction Y of the fiber structure 11 .

In the second fiber base material 20, the yarn main axis of the warp T extends in the depth direction Y of the fiber structure 11, and the yarn main axis of the weft R extends in the direction orthogonal to the depth direction Y and the stacking direction Z of the fiber structure 11. extended.

As shown in FIG. 2 , the second fiber base material 20 is overlaid on the flange 11 b composed of the pair of flange-constituting portions 16 . The second fiber base material 20 has a first surface 20c facing the pair of first flange surfaces 16a on one end surface in the stacking direction Z, and a second surface 20d on the other end surface in the stacking direction Z.

The main body portion 11a of the fiber structure 11 is formed by integrating a pair of base portions 15 with the first base surfaces 15a facing each other. The flange 11b of the fiber structure 11 is formed by integrating the first flange surfaces 16a of the pair of flange forming portions 16 with the first surface 20c of the second fiber base material 20 facing each other.

In the fiber structure 11 configured as described above, the amount of fiber per unit volume is defined as the fiber volume content Vf. The higher the fiber volume content Vf, the greater the amount of fibers contained in a unit volume and the narrower the spacing between fibers. On the other hand, the lower the fiber volume content rate Vf, the smaller the amount of fibers contained in the unit volume, and the more space between fibers. In the present embodiment, the fiber volume content Vf of the fiber structure 11 is 55 to 65%, but the fiber volume content Vf may be appropriately changed according to the purpose of use of the fiber reinforced composite material 10.

Since the fiber structure 11 has the second fiber base material 20 integrated with the first fiber base material 12 , the branched portion 18 is covered with the second fiber base material 20 . The fiber structure 11 has a gap S defined by covering the branched portion 18 with the second fiber base material 20 , and the gap S is filled with the gap filling member 30 . The gap S is between the first curved surface 17a of one L-shaped fibrous body 13, the first curved surface 17a of the other L-shaped fibrous body 13, and the first surface 20c of the second fiber base material 20. is defined as Moreover, the gap S extends over the entire depth direction Y of the fiber structure 11 .

As shown in FIG. 3 or 4, the gap filling member 30 is formed of discontinuous reinforcing fibers H. As shown in FIG. 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 fibers obtained by mixing organic fibers and inorganic fibers may be used. Examples of organic fibers include acrylic fibers, nylon fibers, polyester fibers, aramid fibers, poly-p-phenylenebenzobisoxazole fibers, ultra-high molecular weight polyethylene fibers, etc. Examples of inorganic fibers include carbon fibers, glass fibers, and ceramic fibers. etc. In this embodiment, the discontinuous fibers H are made of carbon fibers.

As shown in FIG. 4, the gap filling member 30 includes a twisted yarn 31 of discontinuous fibers H and a plurality of covering yarns 32 spirally wound around the twisted yarn 31 of discontinuous fibers H. As shown in FIG. The covering thread 32 is made of hot-melt fiber, such as nylon fiber. The gap filling member 30 is a fiber bundle in which the lengths of discontinuous fibers H are aligned in the axial direction of the gap filling member 30 . The twisted yarn 31 of the gap filling member 30 is bulkier than a fiber bundle formed by arranging a plurality of continuous fibers. Further, in the gap filling member 30 , the discontinuous fibers H are oriented so that the longitudinal direction extends in the axial direction of the gap filling member 30 .

The axial dimension of the gap filling member 30 is preferably 60% or more of the overall dimension of the gap S along the depth direction Y. It has dimensions that span the Y direction. That is, the dimension of the gap filling member 30 in the axial direction is the same as the dimension of the gap S in the depth direction Y. As shown in FIG. Further, the amount of the gap filling member 30 to be filled in the gap S is adjusted so that the fiber volume content Vf in the gap S of the fiber structure 11 is equal to or less than the fiber volume content Vf in the portion other than the gap S. be done. In the present embodiment, the fiber volume content Vf in the gap S is adjusted to 30 to 55%, but the fiber volume content Vf in the gap S can be changed as appropriate according to the purpose of use of the fiber-reinforced composite material 10. may

As shown in FIG. 1, in the fiber-reinforced composite material 10 using the fiber structure 11 having the above configuration as the reinforcing base material, the gap S is filled with a plurality of gap filling members 30, and the gap S is discontinuous. The amount of fibers H is adjusted so as to achieve the desired fiber volume fraction Vf. Further, as shown in FIG. 3 , the longitudinal direction of the discontinuous fibers H of the gap filling member 30 is oriented so as to extend in the depth direction Y of the fiber structure 11 . Therefore, the periphery of the gap S in the fiber-reinforced composite material 10 is reinforced in the depth direction Y by the discontinuous fibers H that are filled.

Next, a method for manufacturing the fiber-reinforced composite material 10 using the fiber structure 11 as a reinforcing base material will be described together with its operation.
First, the first fiber base material 12 having a T-shaped cross section and the flat second fiber base material 20 are manufactured. Next, as shown in FIG. 5 , a plurality of gap filling members 30 are placed on the branched portion 18 of the first fiber base material 12 . At this time, the number of gap filling members 30 to be placed is adjusted so that the fiber volume content Vf of the gap S to be formed later becomes a desired value. Then, only by placing the gap filling member 30 on the branched portion 18, the treatment of the portion that will later become the gap S of the fiber structure 11 is completed. That is, the work required to reinforce the periphery of the gap S in the fiber-reinforced composite material 10 is completed.

Next, as shown in FIG. 6, the second fiber base material 20 is placed on the pair of first flange surfaces 16a of the first fiber base material 12, and the first flange surface 16a and the first surface of the second fiber base material 20 are separated. 20c to face each other. As a result, the branched portion 18 is covered with the second fiber base material 20, and a gap S filled with the gap filling member 30 is defined between the first fiber base material 12 and the second fiber base material 20. .

Then, the fiber structure 11 is impregnated with the matrix resin Ma. This impregnation treatment employs a resin transfer molding (RTM) method. Specifically, the fiber structure 11 including the first fiber base material 12, the second fiber base material 20, and the gap filling member 30 is arranged in a mold cavity (not shown). A molten matrix resin Ma is injected into the mold cavity to impregnate the fiber structure 11 with the matrix resin Ma. At this time, the covering yarn 32 melts due to the temperature of the melted matrix resin Ma.

The matrix resin Ma impregnates between the continuous fibers of the warp T, weft R, and interlayer binding yarn of the fiber structure 11 and impregnates between the non-continuous fibers H of the gap filling member 30 . After that, the fiber-reinforced composite material 10 is formed by curing the matrix resin Ma.

According to the above embodiment, the following effects can be obtained.
(1) The gap filling member 30 filled in the gap S of the fiber structure 11 is a fiber bundle of discontinuous fibers H, and thus has a string shape. For this reason, it is easier to handle than, for example, the case where a non-woven fabric is arranged in the branched portion 18, and there is no need to shape the shape of the branched portion 18 unlike the non-woven fabric, so the gap filling member 30 is arranged in the branched portion 18. work is easy.

In the fiber-reinforced composite material 10, the discontinuous fibers H are reinforced around the gap S. By simply adjusting the number of gap filling members 30 that fill the gap S, the amount of discontinuous fibers H that fill the gap S can be adjusted to an amount suitable for reinforcement. For this reason, for example, in order to reinforce the periphery of the gap S, compared to preparing a plurality of types of reinforcing materials or manufacturing a reinforcing member that follows the shape of the gap S, the fiber reinforced composite material 10 The work required to reinforce the periphery of the gap S in can be easily performed.

(2) The gap filling member 30 is a fiber bundle of discontinuous fibers H. As shown in FIG. For example, compared to a fiber bundle in which continuous fibers are aligned, the gaps between the discontinuous fibers H are more likely to open, making it easier to impregnate the matrix resin Ma. Therefore, in the fiber-reinforced composite material 10 using the fiber structure 11 as the reinforcing base material, the matrix resin Ma sufficiently permeates between the discontinuous fibers H of the gap filling member 30 to form a resin-rich portion. can be suppressed, and the periphery of the gap S in the fiber-reinforced composite material 10 can be reinforced.

(4) The number of gap filling members 30 is adjusted so that the fiber volume content Vf in the gap S is equal to or less than the fiber volume content Vf of the first fiber base material 12 and the second fiber base material 20 . Therefore, the fiber volume content Vf in the gap S does not become too high, and it is possible to prevent impregnation of the matrix resin Ma into the gap filling member 30 in the gap S when the fiber-reinforced composite material 10 is manufactured.

(5) The axial dimension of the gap filling member 30 is 60% or more of the dimension of the gap S in the depth direction Y. Therefore, the discontinuous fibers H of the gap filling member 30 are oriented so as to extend in the depth direction Y, and in the fiber-reinforced composite material 10, the strength in the depth direction Y in the gap S can be ensured by the gap filling member 30.

(6) The gap filling member 30 is obtained by shape-retaining the twisted yarn 31 made of the discontinuous fibers H with the covering yarn 32 . Therefore, when the gap filling member 30 is arranged at the branched portion 18 , the discontinuous fibers H can be prevented from coming apart, and the gap filling member 30 can be easily arranged at the branched portion 18 .

(7) The gap filling member 30 arranged at the branch portion 18 is string-like. Therefore, the axial direction of the gap filling member 30 is arranged along the depth direction Y of the branch portion 18 at the branch portion 18 . Therefore, it is easy to dispose the gap filling member 30 even in a narrow portion such as the branch portion 18 of the first fiber base material 12 .

(8) The gap filling member 30 is a fiber bundle in which the discontinuous fibers H are arranged so that their lengths extend in the axial direction of the gap filling member 30, and is different from the nonwoven fabric in which the discontinuous fibers H are randomly oriented. Therefore, when the fiber-reinforced composite material 10 is manufactured, the gap filling member 30 in the gap S can be prevented from flowing out of the gap S due to the injection pressure of the matrix resin Ma.

(9) The size of the gap S between the fiber structures 11 varies depending on the size and shape of the fiber-reinforced composite material 10 . The gap filling members 30 are string-like, and the gap filling members 30 can be filled according to the size and shape of the gap S only by adjusting the number of the gap filling members 30 . Therefore, there is no need to manufacture a filling member that matches the size and shape of the gap S, and the work for reinforcing the periphery of the gap S is facilitated.

(10) Since the fiber volume content Vf of the gap filling members 30 can be grasped in advance, it is easy to adjust the fiber volume content Vf in the gap S by adjusting the number of the gap filling members 30 .
(11) The gap filling member 30 is a fiber bundle of discontinuous fibers H and is bulky. Therefore, when the gap-filling members 30 are arranged in the branched portion 18, even if the gap-filling members 30 are stacked, the gap-filling members 30 and the discontinuous fibers H of the gap-filling members 30 are opened. status can be secured. Therefore, the gap filling member 30 can also be impregnated with the matrix resin Ma.

This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
○ As shown in FIG. 7, the gap filling member 40 may have a configuration including a core yarn 41, a covering layer 42 covering the core yarn 41, and a covering yarn 43 wound around the covering layer 42. good. The core yarn 41 is a twisted yarn formed by twisting continuous fibers. The covering layer 42 is a twisted yarn made of discontinuous fibers H. As shown in FIG.

When configured in this manner, the gap filling member 40 includes the core yarn 41 made of continuous fibers, so that the shape of the gap filling member 40 that is given straightness by the core yarn 41 can be easily maintained, and the branching portion 18 can be easily moved. It is easy to arrange the gap filling member 40 .

○ The fiber structure 11 may be formed by integrating the first fiber base material 12 having a T-shaped cross section and the second fiber base material 20 having a T-shaped cross section. The second fiber base material 20 is integrated with the branched portions 18 facing each other, and the gap S has a substantially rectangular cross section along the stacking direction Z. As shown in FIG.

O The total length of the gap filling member 30 may be shorter than the dimension in the depth direction Y of the branch portion 18 . In this case, the gap filling member 30 is arranged over the entire depth direction Y of the branch portion 18 by connecting the gap filling members 30 in the yarn main axis direction.

O The total length of the gap filling member 30 may be longer than the dimension in the depth direction Y of the branch portion 18 . In this case, the portion protruding in the depth direction Y from the branching portion 18 is cut off, and the gap filling member 30 is arranged over the entire depth direction Y of the branching portion 18 .

○ The gap filling member 30 may have a configuration in which the discontinuous fibers H are only twisted without the covering yarn 32 .
O The gap filling member 30 may be a non-twisted yarn of discontinuous fibers H.

O In the embodiment, the branched portion 18 is formed by integrating the pair of L-shaped fibrous bodies 13, but the branched portion 18 may be formed by bifurcating one sheet of fibrous body.
(circle) although the thermosetting resin was used as matrix resin Ma, you may use other types of resin.

(circle) the matrix material may be a ceramic other than the matrix resin Ma.
(circle) in the 1st fiber base material 12 and the 2nd fiber base material 20, the number of the fiber layers laminated|stacked may be changed arbitrarily.

(circle) the 2nd fiber base material 20 may be comprised with one single-layer textile fabric formed by plain weaving, twill weaving, or satin weaving.

H... Non-continuous fiber, Ma... Matrix resin as matrix material, S... Gap, Y... Depth direction, Z... Stacking direction, Vf... Fiber volume content, 10... Fiber reinforced composite material, 11... Fiber structure, 11a Main body 12 First fiber base material 13a, 20a Warp layers as fiber layers 13b, 20b Weft layers as fiber layers 18 Branching part 20 Second fiber base material 30, 40 ... gap-filling member, 41 ... core thread, 42 ... covering layer.

Claims (5)

The fiber structure of a fiber-reinforced composite material formed by impregnating the fiber structure with a matrix material,
a first fiber base material having a body portion in which a plurality of fiber layers of reinforcing fibers are laminated, and having a branch portion in which the body portion is bifurcated along the lamination direction of the fiber layers;
A second fiber base material that covers the branch and is integrated with the first fiber base material,
A gap filling member that fills a gap defined by the branched portion and the second fiber base material,
The gap filling member is twisted yarn or non -twisted yarn of discontinuous fibers, the length of the discontinuous fibers is oriented so as to extend in the axial direction of the gap filling member, and the length of the discontinuous fibers is the shorter than the axial length of the gap-filling member;
A fiber structure , wherein the gap is filled with a plurality of gap filling members . The second fiber base material has a plurality of laminated fiber layers of reinforcing fibers, and a direction orthogonal to the stacking direction of the fiber layers in the second fiber base material and the stacking direction of the fiber layers in the main body is Assuming the depth direction, the branched portion extends continuously along the depth direction, the gap extends over the entire depth direction of the fiber structure, and the axial dimension of the gap filling member is The fiber structure according to claim 1, which is 60% or more of the dimension of the gap in the depth direction. 3. The fiber volume content ratio indicating the amount of the discontinuous fibers per unit volume of the gap is equal to or lower than the fiber volume content ratio indicating the amount of the reinforcing fibers per unit volume in the main body. The fiber structure according to . The fiber structure according to any one of claims 1 to 3, wherein the twisted yarn or untwisted yarn of discontinuous fibers comprises a core yarn made of continuous fibers extending in the entire axial direction of the gap filling member. A fiber-reinforced composite material comprising a fiber structure impregnated with a matrix material, wherein the fiber structure is the fiber structure according to any one of claims 1 to 4. material.