JP6157186B2 - Manufacturing method of fiber reinforced composite material structure - Google Patents

Description

The present invention relates to a manufacturing method of the fiber-reinforced composite structure with a fiber-optic sensor is a strain sensor.

  A lightweight and highly rigid fiber-reinforced composite material structure is generally used for the structure of an artificial satellite. In particular, the mission mounting structure uses a highly rigid honeycomb sandwich structure composed of a fiber reinforced plastic skin material and a honeycomb core as a fiber reinforced composite material structure.

  However, since the thermal deformation of the fiber reinforced composite material structure occurs due to changes in the on-orbit thermal environment such as solar heat input and on-board equipment heat generation, the angle of the earth-oriented axis in mission equipment such as on-board cameras and antennas Will fluctuate. In particular, in geostationary satellites located at a distance of about 36,000 km from the earth, the accuracy of earth observation and positioning will be significantly reduced even if the pointing axis angle varies slightly.

  In order to prevent such a significant decrease in accuracy, it is important to suppress thermal deformation, predict fluctuations in the pointing axis angle due to thermal deformation, and correct the pointing axis. And in order to predict the variation of the pointing axis angle due to thermal deformation, it is necessary to measure the strain of the fiber-reinforced composite material structure on the track with high density and high accuracy.

  Here, an optical fiber sensor has been proposed as one of sensors for evaluating the strain of a fiber reinforced plastic or plastic structure. This optical fiber sensor is a small and lightweight temperature sensor or strain sensor that is used in a state where it is embedded in a fiber reinforced plastic or plastic structure, or is adhered to the surface of the structure. Or

  As an example of a fiber reinforced composite material structure including such an optical fiber sensor, an optical fiber sensor in which an FBG (Fiber Bragg Grating) in which the Bragg wavelength of the reflection spectrum changes according to temperature or strain is formed is embedded inside. There is a rib structure made of fiber reinforced plastic (for example, see Patent Document 1). Thus, by providing a structure in which an optical fiber sensor is embedded inside a fiber reinforced plastic rib structure, it is possible to measure the strain distribution in the structure.

Japanese Patent No. 4216202

However, the prior art has the following problems.
In the prior art described in Patent Document 1, as described above, an optical fiber sensor is embedded and the strain distribution in the structure is measured. In the fiber reinforced plastic in the rib structure, the reinforcing fibers are oriented in one direction, and the orientation direction of the reinforcing fibers is parallel to the orientation direction of the optical fiber.

  Here, for example, in a fiber reinforced composite material structure (fiber reinforced plastic structure) used for the structure of an artificial satellite, in order to control the thermal and mechanical characteristics of the structure, the reinforcing fibers are not unidirectional, It is often oriented in the direction.

  As described above, when the reinforcing fibers are oriented in a plurality of directions, the reinforcing fibers in at least one direction intersect with the optical fibers when the optical fiber sensor is embedded therein, as in the conventional technique. As a result, there is a problem that the reinforcing fiber is bent around the optical fiber. In addition, when the reinforcing fiber is bent, the reinforcing fiber at the bent portion (the portion where the reinforcing fiber is bent) cannot bear the load, so that there is a problem that desired mechanical properties cannot be obtained as the entire structure. .

The present invention has been made in order to solve the above-described problems, and even when an optical fiber sensor is embedded in a state where the reinforcing fibers are oriented in a plurality of directions, It suppresses and controls the bending, and to obtain a method for manufacturing a high density and high precision fiber-reinforced composite material structure that can of evaluating the distortion.

  The fiber reinforced composite material structure manufacturing method according to the present invention includes an optical fiber including an optical fiber having one or more sensor portions for detecting strain, and a resin layer covering the periphery of the optical fiber. A method of manufacturing a fiber reinforced composite material structure for manufacturing a fiber reinforced composite material structure in which a sensor structure is embedded, wherein an optical fiber is covered with an uncured resin and heated under pressure to produce light. The cross section of the resin layer in the plane perpendicular to the fiber orientation direction is the highest point at the position of the optical fiber, and as the distance from the optical fiber increases, the thickness of the optical fiber decreases with a resin layer around the optical fiber. A first step of covering and an optical fiber whose periphery is covered with a resin layer are placed at a desired interlayer position of a plurality of prepregs, and a plurality of prepregs are sequentially laminated and heated under pressure. A second step that is those with.

According to the present invention, an optical fiber sensor structure in which a taper resin layer is formed around an optical fiber is embedded between layers of a prepreg (fiber reinforced plastic) so that the orientation of the reinforcing fiber around the optical fiber is continuous. To change slowly. As a result, even when the optical fiber sensor is embedded in a state in which the reinforcing fibers are oriented in a plurality of directions, the bending of the reinforcing fibers is controlled and suppressed, and the strain is highly dense and highly accurate. manufacturing method of evaluation can Ru fiber-reinforced composite material structure able to can be obtained.

It is a perspective view of the fiber reinforced composite material structure in Embodiment 1 of this invention. It is sectional drawing of the fiber reinforced composite material structure in Embodiment 1 of this invention. It is sectional drawing of the optical fiber sensor structure in Embodiment 1 of this invention. It is an expanded sectional view near the FBG sensor part in the optical fiber in Embodiment 1 of this invention. It is explanatory drawing which shows the structure of the FBG sensor part in Embodiment 1 of this invention. It is a graph which shows the characteristic of the reflection spectrum of the FBG sensor part in Embodiment 1 of this invention. It is a block diagram of the distortion | strain measurement system using the optical fiber sensor structure in Embodiment 1 of this invention. In Embodiment 1 of this invention, it is explanatory drawing which showed a mode that a taper resin layer was shape | molded by the optical fiber sensor structure. In Embodiment 1 of this invention, it is explanatory drawing which showed the thickness of the taper resin layer in an optical fiber sensor structure. In Embodiment 1 of this invention, it is explanatory drawing which showed a mode that an optical fiber sensor structure was embedded between the layers of a fiber reinforced plastic, and a fiber reinforced composite material structure was shape | molded. It is explanatory drawing for demonstrating a series of manufacturing processes of the fiber reinforced composite material structure in Embodiment 1 of this invention.

Hereinafter, a method for manufacturing by that fiber-reinforced composite structure of the present invention will be described with reference to the drawings in accordance with a preferred embodiment. In the description of the drawings, the same reference numerals are assigned to the same elements, and duplicate descriptions are omitted.

  Here, the fiber reinforced composite material structure in the present invention is formed in a state where the optical fiber sensor structure in which the periphery of the optical fiber is covered with the taper-shaped resin layer is embedded between the layers of the prepreg. It has the technical feature that it can control and suppress the bending of the fiber and can evaluate the strain with high density and high accuracy. Therefore, in the present application, it is meaningful that the fiber-reinforced composite material structure has such a structure, and the specific numerical values shown in the following Embodiment 1 are examples and affect the scope of rights. It is not a thing.

Embodiment 1 FIG.
First, a coordinate system used in the following description will be described. When the fiber-reinforced composite material structure of the first embodiment is shown, any one direction in the in-plane direction is defined as the X direction, and the in-plane direction perpendicular to the Y direction is defined as the Y direction and the out-of-plane direction is defined as the Z direction. Moreover, when showing the orientation direction of the reinforced fiber in a fiber reinforced composite material structure, the X direction is the 0 degree direction and the Y direction is the 90 degree direction.

  Next, the fiber-reinforced composite material structure according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of a fiber-reinforced composite material structure according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the fiber-reinforced composite material structure according to Embodiment 1 of the present invention. 2 is a cross section orthogonal to the orientation direction (X direction) of the optical fiber of the fiber reinforced composite material structure in FIG. 1 (that is, parallel to the YZ plane). FIG.

  As shown in FIG. 1, the fiber reinforced composite material structure includes a fiber reinforced plastic 1 and an optical fiber sensor structure 2. More specifically, an optical fiber sensor structure 2 for detecting strain is embedded between the layers of the fiber reinforced plastic 1. The optical fiber sensor structure 2 is oriented in the X direction (0 degree direction) as shown in FIG.

  The optical fiber sensor structure 2 embedded between the layers of the fiber reinforced plastic 1 includes an optical fiber 3, a coating 4, and a taper resin layer 5. In addition, in FIG. 2, in order to demonstrate concretely, the case where it was embedded between the 2nd layer and the 3rd layer of the fiber reinforced plastic 1 laminated | stacked by 4 layers is illustrated.

  As shown in FIG. 2, the optical fiber 3 in the optical fiber sensor structure 2 is covered with the outer periphery by a coating 4, and the optical fiber 3 (the coating 4) is surrounded by a taper resin layer 5. Covered. Note that the range in which the taper angle θ of the taper resin layer 5 can be practically used is, for example, 0 ° <θ <15 °, but is not limited thereto.

  Further, the layers of the fiber reinforced plastic 1 (the third layer and the fourth layer in FIG. 2) located above the optical fiber 3 are gently bent along the taper resin layer 5, The reinforcing fiber is bent similarly. That is, the orientation of the reinforcing fibers around the optical fiber 3 continuously and gently changes, and the bending of the reinforcing fibers is suppressed.

  Next, the FBG sensor unit 6 formed in the optical fiber 3 will be described with reference to FIGS. FIG. 3 is a cross-sectional view of the optical fiber sensor structure 2 according to Embodiment 1 of the present invention. FIG. 4 is an enlarged cross-sectional view of the vicinity of the FBG sensor portion 6 formed in the optical fiber 3 according to Embodiment 1 of the present invention. FIG. 5 is an explanatory diagram showing the structure of the FBG sensor unit 6 according to Embodiment 1 of the present invention. FIG. 6 is a graph showing the characteristics of the reflection spectrum of the FBG sensor unit 6 according to Embodiment 1 of the present invention.

  The cross-sectional view of the optical fiber sensor structure 2 in FIG. 3 is parallel to the optical fiber orientation direction (X direction) of the optical fiber sensor structure 2 in FIG. Shows a cross-sectional view. FIG. 3 also shows the above-described FBG sensor unit 6 in addition to the optical fiber 3, the coating 4, and the tapered resin layer 5.

  4 is an enlarged view of the vicinity of the FBG sensor unit 6 shown in the cross-sectional view of the optical fiber sensor structure 2 in FIG.

  Here, the FBG sensor unit 6 is a fiber Bragg grating unit formed in the optical fiber 3, and is spaced from each other so as to be connected in series by the optical fiber 3. One or more are provided. Note that FIG. 3 illustrates a case where the three FBG sensor units 6 are provided at intervals from each other for specific description.

  And as shown in FIG. 3, the circumference | surroundings of the optical fiber 3 in which the FBG sensor part 6 is formed are not covered with the coating | cover 4 (the coating | coated 4 is removed), with respect to this, the FBG sensor part The periphery of the optical fiber 3 where 6 is not formed is covered with a coating 4.

  Specifically, as shown in FIG. 4, the optical fiber 3 includes a core 7 and a clad 8 that covers the outer periphery of the core 7, and the FBG sensor unit 6 is formed in the core 7. The outer periphery of the cladding 8 is covered with the coating 4, and the coating 4 is removed in the vicinity of the FBG sensor portion 6, so that the cladding 8 is exposed.

  As for the size of each part in the optical fiber 3, for example, the diameter of the entire optical fiber 3 including the coating 4 can be about 250 μm, the diameter of the cladding 8 can be about 125 μm, and the diameter of the core 7 can be about 10 μm. However, it is not limited to these sizes. Each of the plurality of FBG sensor units 6 can be formed in the core 7 over a range of about 5 mm, for example, but is not limited to this range. Thus, the optical fiber according to the numerical values shown here is an example, and the present invention is applicable to optical fibers according to other numerical values than the numerical values shown here.

Further, the FBG sensor unit 6 is formed in the core 7 so that the refractive index periodically changes in the longitudinal direction (orientation direction) of the optical fiber 3, and has a feature that a steep reflection spectrum characteristic can be obtained. Have. Specifically, as shown in FIG. 5, the refractive index of the core 7 changes with a period Λ, and as shown in FIG. 6, a steep reflection spectrum characteristic is obtained, and the center wavelength (Bragg wavelength: λ) of the reflection spectrum is obtained. _B ) has the highest light intensity.

Here, the relationship between the center wavelength (Bragg wavelength: λ _B ), the period Λ, and the refractive index n of the reflection spectrum is expressed by the following equation (1). The refractive index n depends on temperature, and the period Λ depends on temperature and strain.
λ _B = 2nΛ (1)

Therefore, the Bragg wavelength λ _B is measured in a state where the optical fiber sensor structure 2 is embedded between the layers of the fiber reinforced plastic 1. And if the influence of the temperature of the fiber reinforced composite material structure measured using another known means is taken into consideration, the temperature can be obtained from the above equation (1), and the strain generated in the fiber reinforced composite material structure Can be evaluated with high density and high accuracy. Thus, the FBG sensor unit 6 formed in the optical fiber 3 can be used as a strain sensor.

  Although the vicinity of the FBG sensor unit 6 may be covered with the coating 4, as described above, the coating 4 is removed so that the periphery of the optical fiber 3 on which the FBG sensor unit 6 is formed is not covered with the coating 4. If it does so, the information of the distortion which arose in the fiber reinforced composite material structure can be transmitted to the FBG sensor part 6 more correctly. Therefore, in order to measure distortion more accurately, it is preferable that the periphery of the optical fiber 3 on which the FBG sensor unit 6 is formed is not covered with the coating 4. In addition, since the taper resin layer 5 covering the periphery of the optical fiber 3 on which the FBG sensor unit 6 is formed is integrated with the fiber reinforced plastic 1, information on the strain generated in the fiber reinforced composite material structure is transmitted to the FBG sensor unit. 6 is accurately transmitted, and the measurement accuracy of distortion is hardly affected.

  Next, an example of a strain measurement system for evaluating the strain of the fiber-reinforced composite material structure will be described with reference to FIG. FIG. 7 is a configuration diagram of a strain measurement system using the optical fiber sensor structure 2 according to Embodiment 1 of the present invention.

  As shown in FIG. 7, the strain measurement system includes an optical fiber 3, an optical circulator 9, an ASE (Amplified Spontaneous Emission) light source 10, and an optical wavelength meter 11.

  When measuring the temperature of the fiber reinforced composite material structure, an optical circulator 9 for converting the optical path is connected to the proximal end portion of the optical fiber 3. The optical circulator 9 is connected to an ASE light source 10 that is a broadband light source and an optical wavelength meter 11 that is a wavelength measuring device.

By configuring such a system, the Bragg wavelength λ _B can be specifically measured. Then, as described above, when the Bragg wavelength λ _B is measured and the influence of the temperature of the fiber reinforced composite material structure measured using another known means is taken into consideration, the temperature is obtained from the above equation (1). The strain generated in the fiber reinforced composite material structure can be evaluated with high density and high accuracy.

  Next, the manufacturing method of the fiber reinforced composite material structure in the first embodiment will be described with reference to FIGS.

  First, a case where the optical fiber sensor structure 2 is manufactured by forming the tapered resin layer 5 around the optical fiber 3 will be described with reference to FIGS. 8 and 9. FIG. 8 is an explanatory diagram showing a state in which the tapered resin layer 5 is formed on the optical fiber 3 in the first embodiment of the present invention. FIG. 9 is an explanatory diagram showing the thickness of the taper resin layer 5 in the optical fiber sensor structure 2 in Embodiment 1 of the present invention. Here, FIG. 9A shows a cross-sectional view of the optical fiber sensor structure 2 in FIG. 3, and FIG. 9B shows a cross-sectional view along AA ′ in FIG. c) shows a BB ′ cross-sectional view in (a).

  Here, in order to measure the strain of the fiber reinforced composite material structure with higher accuracy, as described above, the coating of the optical fiber 3 on which the FBG sensor unit 6 is formed is not covered with the coating 4. 4 is removed, and the vicinity of the FBG sensor unit 6 is exposed in advance.

  As shown in FIG. 8, the periphery of the optical fiber 3 is sandwiched between uncured resins (specifically, two tape-shaped resin films 12), placed in the groove of the grooved mold 13, and the surface plate 14. Press down on the top. Then, using a press machine (not shown), a predetermined molding pressure is applied to each of the tape-shaped resin films 12 through the grooved mold 13 and the surface plate 14 and heated under pressure.

  In addition, as the tape-shaped resin film 12, for example, an epoxy adhesive having a thickness of 60 μm and curing at 180 ° C. can be used. An adhesive may be used. Further, when the taper resin layer 5 is formed, the optical fiber 3 is sandwiched between the two tape-shaped resin films 12, but the present invention is not limited to this. For example, a liquid adhesive is applied to the optical fiber 3 to form a film. You may adhere | attach with an adhesive agent.

  Thus, the optical fiber sensor structure 2 can be manufactured by forming the tapered resin layer 5 around the optical fiber 3. Specifically, as shown in FIG. 9A, in the optical fiber sensor structure 2, a taper resin layer 5 covers the periphery of the optical fiber 3.

  Further, as shown in FIG. 9B, the optical fiber 3 that is not covered with the coating 4 (that is, the optical fiber 3 on which the FBG sensor portion 6 is formed is located at the center of the taper resin layer 5; The thickness (layer thickness) of the resin layer corresponding to this position is the largest, and as the distance from the position of the optical fiber 3 to the lower part of the taper resin layer 5 is increased in the direction parallel to the taper resin layer 5 (left and right in the drawing), Similarly, as shown in Fig. 9C, the optical fiber 3 covered with the coating 4 is also located at the center of the taper resin layer 5 and corresponds to this position. The thickness of the resin layer is the largest, and the thickness of the resin layer decreases as the distance from the position of the optical fiber 3 increases in the direction parallel to the lower portion of the taper resin layer 5 (left and right in the drawing).

  In other words, as shown in FIGS. 9B and 9C, the cross-sectional shape of the taper resin layer 5 on the surface orthogonal to the orientation direction of the optical fiber 3 becomes the highest point at the position of the optical fiber 3. As the distance increases, the layer thickness decreases in a tapered manner.

  9B and 9C show examples of the cross-sectional shape and taper angle θ of the taper resin layer 5 that can continuously and gently change the orientation of the reinforcing fibers around the optical fiber 3. Although illustrated, it is not limited to this. That is, the groove shape of the grooved mold 13 can be appropriately changed by processing the groove shape into a desired shape. Thus, by changing the cross-sectional shape of the taper resin layer 5 and the taper angle θ, the degree of bending of the reinforcing fibers around the optical fiber 3 can be controlled to be a desired degree of bending. Further, the orientation of the reinforcing fibers around the optical fiber 3 can be continuously and gently changed.

  Next, the case where the optical fiber sensor structure 2 is embedded between the layers of the fiber reinforced plastic 1 to form a fiber reinforced composite material structure will be described with reference to FIG. FIG. 10 is an explanatory view showing a state in which the fiber reinforced composite structure is formed by embedding the optical fiber sensor structure 2 between the layers of the fiber reinforced plastic 1 in the first embodiment of the present invention.

  As shown in FIG. 10, a plurality of prepregs 15 are sequentially laminated on the surface plate 14 as a layer of the fiber reinforced plastic 1. The prepreg 15 is preferably in a state in which a resin is impregnated between fibers in advance and semi-cured. Further, the optical fiber sensor structure 2 is installed so that it is arranged at a desired interlayer position of the prepreg 15 and further, the FBG sensor unit 6 is arranged at a desired in-plane position on the prepreg 15.

  Next, after the optical fiber sensor structure 2 is installed and a predetermined number of prepregs 15 are laminated, the whole is covered with a bagging film 16, sealed with a sealing material 17, and the inside (sealed space) is pumped. A vacuum state is applied (not shown). In this state, the molding material 18 is molded by heating from above the bagging film 16 under pressure (for example, pressurizing at about 1 atm). And the fiber reinforced composite material structure is shape | molded by hardening resin contained in the prepreg 15 in this molding material 18. FIG.

  In addition, as the prepreg 15 used as the material of the fiber reinforced plastic 1, for example, a carbon fiber prepreg composed of carbon fiber M60J (manufactured by Toray Industries, Inc.) and an epoxy resin cured at 170 ° C. can be used. It is not limited to. That is, the configuration of the prepreg 15 that can be used here is not limited to the combination of the carbon fiber M60J and the epoxy resin that is cured at 170 ° C., and may be any combination. As described above, the combination of the fiber constituting the prepreg and the resin shown here is an example, and the present invention can be applied to a prepreg composed of other combinations.

  The grating length of the FBG sensor unit 6 can be, for example, 5 mm. However, the length is not limited to this, and any length may be used as long as the length is in the range of about 1 mm to 10 mm. There may be.

  Next, a series of manufacturing steps of the fiber-reinforced composite material structure detailed up to here will be described more specifically with reference to FIG. FIG. 11 is an explanatory diagram for describing a series of manufacturing steps of the fiber-reinforced composite material structure according to Embodiment 1 of the present invention. In addition, since it mentioned above about the process of manufacturing the optical fiber sensor structure 2 by shape | molding the taper resin layer 5 around the optical fiber 3, description is abbreviate | omitted.

  First, as a first step, as described above, one or more prepregs 15 are sequentially laminated on the surface plate 14. A group of prepregs composed of one or more prepregs 15 stacked in the first step is referred to as a first prepreg group 19.

  Next, as a second step, the optical fiber sensor structure 2 is installed on the first prepreg group 19 laminated in the first step.

  Next, as a third step, one or more prepregs 15 are sequentially laminated on the first prepreg group 19 having the optical fiber sensor structure 2 installed thereon. A group of prepregs composed of one or more prepregs 15 stacked in the third step is referred to as a second prepreg group 20.

  Next, as a fourth step, the resin in the prepreg 15 is cured by heating the first prepreg group 19 and the second prepreg group 20 under pressure. As a result, the fiber-reinforced composite material structure (the fiber-reinforced composite material structure including the optical fiber sensor structure 2) according to the first embodiment is manufactured.

  Here, when the optical fiber sensor structure 2 in a state where the optical fiber 3 (coating 4) is not covered with the taper resin layer 5 is embedded between the layers of the fiber reinforced plastic 1 (interlayer of the prepreg 15), an optical fiber sensor structure is obtained. The reinforcing fiber is bent greatly around the body 2.

  In addition, since the reinforcing fiber of the bent portion that is greatly bent cannot bear the load, the mechanical properties as the fiber-reinforced composite material structure are lowered, and desired mechanical properties cannot be obtained. Furthermore, since the degree of bending indicating how much the reinforcing fiber bends cannot be controlled, it is impossible to estimate the degree of reduction indicating how much the actual mechanical characteristics are reduced from the desired mechanical characteristics. As a result, in order to obtain desired mechanical properties, the prepreg 15 is excessively laminated, leading to an increase in the weight of the fiber-reinforced composite material structure.

  In contrast, in the present invention, the optical fiber sensor structure 2 in a state where the optical fiber 3 (coating 4) is covered with the taper resin layer 5 is embedded between the layers of the fiber reinforced plastic 1 (interlayer of the prepreg 15). Therefore, the reinforcing fibers are gently bent, and the deterioration of the mechanical properties as the fiber-reinforced composite material structure is suppressed.

  Further, since the taper angle θ can be changed, the degree of bending of the reinforcing fiber can be controlled. That is, since the inclination with respect to the orientation direction of the reinforcing fiber is determined by the taper resin layer 5, the bending of the reinforcing fiber around the optical fiber sensor structure 2 can be suppressed and controlled, and as a result, the fiber reinforcement Deterioration of mechanical properties as a composite material structure can be minimized.

  Furthermore, in this invention, since the FBG sensor part 6 which is brittle and easy to be destroyed is covered with the taper resin layer 5, the FBG sensor part 6 will be protected. As a result, the strength of the FBG sensor unit 6 is improved, and workability when installing the optical fiber sensor structure 2 can be improved. Moreover, if the taper resin layer 5 is shape | molded with the same kind of resin film as the prepreg 15, it can shape | mold without inserting a dissimilar material and can improve interlayer intensity | strength.

  As described above, according to the first embodiment, in the fiber reinforced composite material structure, the optical fiber sensor in which the taper resin layer is formed around the optical fiber is embedded between the fiber reinforced plastic layers (the prepreg layers). It has a structure. Thereby, even if the reinforcing fibers are oriented in a plurality of directions, the bending of the reinforcing fibers can be controlled and suppressed, and the distortion can be evaluated with high density and high accuracy.

  In the first embodiment, as an example of the optical fiber 3 covered with the taper resin layer 5, an optical fiber in which one or more FBG sensor portions 6 are formed is illustrated, but the present invention is not limited to this, and the present invention. Is applicable to other optical fibers that can evaluate the distortion of the structure. Similarly, in other optical fibers, it is possible to measure the distortion with higher accuracy if the periphery where the sensor unit for detecting the distortion is not covered with the coating.

  DESCRIPTION OF SYMBOLS 1 Fiber reinforced plastic, 2 Optical fiber sensor structure, 3 Optical fiber, 4 Coating | cover, 5 Tapered resin layer, 6 FBG sensor part, 7 Core, 8 Cladding, 9 Optical circulator, 10 ASE light source, 11 Optical wavelength meter, 12 Tape Resin film, 13 grooved mold, 14 surface plate, 15 prepreg, 16 bagging film, 17 sealing material, 18 molding material, 19 first prepreg group, 20 second prepreg group.

Claims (3)

A fiber reinforced composite material structure including an optical fiber in which one or more sensor portions for detecting strain are formed and a resin layer covering the periphery of the optical fiber, in which an optical fiber sensor structure is embedded. A method of manufacturing a fiber-reinforced composite material structure,
By covering the optical fiber with an uncured resin and heating it under pressure, the cross-sectional shape of the resin layer on the surface orthogonal to the orientation direction of the optical fiber becomes the highest point at the position of the optical fiber, and the optical fiber A first step of covering the periphery of the optical fiber with the resin layer so that the layer thickness decreases in a tapered manner as the distance from
A second step of installing the optical fiber, the periphery of which is covered with the resin layer, at a desired interlayer position of a plurality of prepregs, sequentially laminating the plurality of prepregs, and heating under pressure;
A method for producing a fiber-reinforced composite material structure comprising: In the manufacturing method of the fiber reinforced composite material structure according to claim 1 ,
The method for manufacturing a fiber-reinforced composite material structure, further comprising a third step of removing the coating when there is a coating around the optical fiber where the sensor unit is located before the execution of the first step. In the manufacturing method of the fiber reinforced composite material structure according to claim 1 or 2 ,
One or more FBG (fiber Bragg grating) sensor parts are formed as the sensor part in the optical fiber. A method for manufacturing a fiber reinforced composite material structure.

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