Abstract: A method of manufacturing a structure includes: a molding step of impregnating carbon fibers with a resin material and curing the resin material for molding a carbon fiber composite material; a polishing step of polishing a polishing region on a surface of the carbon fiber composite material molded in the molding step, with an abrasive that has a predetermined hardness; and a bonding step of bonding, through an adhesive, another member to a part of the polishing region polished by the polishing step. The molding step forms, in a top layer, a polishing layer that has a hardness which is lower than the predetermined hardness, and forms a surface protective layer that is lower than the polishing layer, protects the carbon fiber composite material from the abrasive, and contains a protective filler having a hardness which is higher than the predetermined hardness.

Abstract: A core (20) and a bag (22, 24) are provided which are used to shape an FRP structure (10; 30). The bag (22, 24) has a core bag section (24) which covers the outer circumference of the core (20), and a coverture bag section (22) which covers a plurality of fiber components (12, 14; 12, 14, 16).

Abstract: A method for manufacturing a resin sheet includes a coating step; a heating step; and a pressurizing step. In the coating step, linear metal nanomaterial is coated on a surface of a resin film having thermal plasticity. In the heating step, the resin film having the linear metal nanomaterial coated on the surface thereof is heated and softened. In the pressurizing step, the resin film having the linear metal nanomaterial coated on the surface thereof is pressurized to press the linear metal nanomaterial along a direction orthogonal to the surface on which the linear metal nanomaterial is coated. Thus, the coated linear metal nanomaterial penetrates the resin film to obtain the resin sheet containing the linear metal nanomaterial.

Abstract: The purpose of the present invention is to provide a bonded structure, a method for manufacturing the same, and a bonding state detection method which are capable of determining whether or not members are bonded together appropriately. A bonded structure 10 includes a laminated sheet 12A, a laminated sheet 12B, an adhesive 14 that bonds the laminated sheet 12A and the laminated sheet 12B together, and a distributed optical fiber 16 sandwiched between the laminated sheet 12A and the laminated sheet 12B. The cross-sectional shape of the distributed optical fiber 16 is deformed in accordance with the bonding state.

Abstract: A composite material forming device includes a pressurizing unit, heating unit, a movement mechanism, and a control unit. The device processes a composite material in which reinforced fibers have been impregnated with a thermosetting resin from a softened state or semi-cured state into a cured state while forming the composite material into a prescribed size and prescribed shape. The pressurizing unit applies pressure to a prescribed region of the composite material. The heating unit applies a magnetic field to the prescribed region of the composite material to which pressure has been applied by the pressurizing unit, thereby heating a prescribed region of the composite material. The movement mechanism causes the pressurization region and heating region to synchronously move by simultaneously changing the position of a first member relative to the composite material and the position of the heating unit relative to the composite material.

Abstract: A method for bonding a first composite material and a second composite material together includes a step in which a first bonding region of the first composite material is prepared to be maintained in a softened state. In another step, a first non-bonding region of the first composite material is heated to be put into a cured state. The first bonding region is put into a heatable state, and the first bonding region is heated to be put into a semi-cured state. The first bonding region having been put into the semi-cured state is pressed in contact with a second bonding region of the second composite material that becomes a softened state or a semi-cured state. The first bonding region and the second bonding region having been brought into contact with each other and pressed in the contacting and pressing step are heated to be put into a cured state.

Abstract: A method is of designing a composite material that includes stacked reinforced fiber substrates and has a thickness-varying part whose thickness in a stacking direction changes from a large thickness to a small thickness. The method includes setting, as a cut substrate, the reinforced fiber substrate that has the drop-off portion and is positioned between a base substrate and a cover substrate in the stacking direction; performing stress analysis on the base substrate, the cut substrate, and the cover substrate to calculate an evaluation value concerning stress on the cut substrate; and setting, as the cut substrate, a reinforced fiber substrate in the thickness-varying part, based on the calculated evaluation value.

Abstract: A method is for designing a structure in which a composite material including fibers and a resin is arranged as a damping material in a structure body. The method includes selecting a divided arrangement area in which the composite material is to be arranged, the divided arrangement areas being one of divided arrangement areas into which a composite material arrangement area of the structure in which the composite material is arrangeable is divided; selecting a lamination position where the composite material is to be arranged in a thickness direction of the structure; selecting a fiber direction of the fibers; and determining whether a design performance of the structure satisfies performance requirements, the design performance being derived from design parameters including at least the selected divided arrangement area, the selected lamination position, and the selected fiber direction.

Abstract: A computer-implemented method is for designing a composite material in which reinforcement fiber base materials are laminated. The composite material includes a hole extending in a lamination direction of the reinforcement fiber base materials and a reinforcement part provided around the hole. The method includes calculating a strain value generated in the composite material based on design factors and a predetermined load condition, the design factors including a shape of the hole, a shape of the reinforcement part, and an orientation angle of each of the reinforcement fiber base materials in respective layers of the reinforcement part; and optimizing the design factors based on a genetic algorithm such that the calculated strain value tends to decrease.

Abstract: This structure is provided with a first composite material 11, a second composite material 12 joined to the first composite material 11 by a film adhesive 21 provided between the first composite material 11 and the second composite material 12, and a corner fillet part 13 provided on a corner part 15 formed by the first composite material 11 and the second composite material 12. The shape of the corner fillet part 13 is a design shape P designed in advance, and the corner fillet part 13 is formed by curing the film adhesive 21 after arranging the film adhesive 21 on the corner part 15 so as to fit into the design shape P.

Abstract: Provided are a lithium secondary battery having improved initial capacity and excellent cycle property, an electrolyte solution for the lithium secondary battery, and an additive for the electrolyte solution for the lithium secondary battery. The lithium secondary battery includes positive and negative electrodes both having a lithium-ion intercalation/de-intercalation ability, and a non-aqueous electrolyte solution contacted with the positive and negative electrodes. The non-aqueous electrolyte solution contains lithium hexafluorophosphate and a boroxine compound represented by (RO)3(BO)3 liquefying at 25° C. R(s) each independently represent an organic group of a linear chain alkyl group having 3 or more carbon atoms. Herein, the chain alkyl group may have a branch, and when the branch is included, the number of carbon atoms of the chain alkyl group constructing a linear portion thereof is 3 or more.

Abstract: A bonded structure includes a first member, a second member, an adhesive that bonds the first member and the second member together, and an optical fiber sandwiched between the first member and the second member. When pressure is applied to the optical fiber only from a predetermined direction, the sectional shape of the optical fiber changes to an elliptical shape, so that birefringence occurs, whereby the shape of the light spectrum changes so as to have multiple peaks. The optical fiber is used as a sensor for detecting the bonding condition between the first member and the second member based on the birefringence.

Abstract: In a composite material structure, which is configured as a fiber-reinforced plastic composite material extending in one direction and having a plurality of holes defined at intervals in a row in the one direction and which is subjected to a tensile load and/or a compressive load in the one direction, a peripheral region around the holes comprises a first area obtained by bending composite material, which is reinforced using continuous fibers that have been made even in a longitudinal direction, so that a center line of a width of the composite material weaves between adjacent holes and zigzags in the one direction. A tensile rigidity and/or a compressive rigidity in the one direction of the peripheral region around the holes is lower than a tensile rigidity and/or a compressive rigidity in the one direction of other regions that surround the peripheral region.

Abstract: An object is to provide a method of evaluating the joint state of a joint portion through kissing bond inspection using a non-destructive technique. A joint evaluation method of evaluating a joint state of a joint portion in a composite including the joint portion in which an adherend and another adherend are joined to each other through an adhesive, the method including the steps of: applying an alternating-current signal to the joint portion; changing frequency to measure current and voltage; calculating an evaluation value related to a given electrical characteristic from a current value and a voltage value obtained by the measurement; comparing the evaluation value with a preset criterion related to the given electrical characteristic; and evaluating the joint state of the joint portion according to the amount of deviation of the evaluation value from the criterion.

Abstract: A joint structure (1) for a composite member made from a composite material. The joint structure includes a plate for increasing thickness (40a, 40b) adhered to at least one side of the composite member (10). The composite member (10) and a counterpart member (20) are fastened together by inserting and fixing a fastener member (30) into a through-hole (24, 26) formed through the composite member (10), the plate for increasing thickness (40a, 40b), and the counterpart member (20) to be joined to the composite member.

Abstract: A member includes a first composite member containing a plastic reinforced with a thermally conductive carbon fiber containing one or both of a metal-coated carbon fiber and a pitch-based carbon fiber, wherein one end of the thermally conductive carbon fiber is disposed in a heat-generating section, and the other end of the thermally conductive carbon fiber is disposed in a heat-radiating section in a fiber direction.

Abstract: Provided is a joint and an aircraft structure wherein it is possible to position a member relative to a preform with high accuracy. A groove into which a plate member (30) is inserted is formed in a pi-shaped joint (20) provided on the preform (21), and the preform (21) and the plate member (30) are connected by being bonded. Moreover, a fitting shape (32A-1) into which the plate member (30) is fitted is formed on the pi-shaped joint (20) on the whole groove bottom face. Additionally, a fitting shape (32A-2) into which the plate member (30) is fitted is formed on a portion of the groove bottom face. Furthermore, fitting shapes (32B-1, 32B-2), into which the groove bottom face that is formed on the pi-shaped joint (20) is fitted, are formed on the surface of the plate material (30) that is fitted with the pi-shaped joint (20).

Abstract: In order to use a laser beam to cure a resin composite material to a high strength with simple equipment, this curing device (1) is provided with: a pressurizing body (4) which is formed from a material that transmits a laser beam (L) (quartz glass, for example) and which, when pressed against the surface of an uncured resin composite material (2), applies pressure on the resin composite material (2); and a laser beam supply unit (5) which irradiates a laser beam (L) through the pressurizing body (4) onto the uncured resin composite material (2). This curing device is further provided with an irradiation position adjustment unit (6) which, within the area pressed by the pressurizing body (4), moves the position irradiated by the laser beam (L) supplied from the laser beam supply unit (5).

Abstract: The purpose of the present invention is to provide a fuel tank, main wings, an aircraft fuselage, an aircraft, and a moving body, which enable working hours and costs involved in a manufacturing process to be reduced, and weight increases to be prevented. The fuel tank includes a structural member in which carbon fiber reinforced plastic (CFRP) is used, the carbon fiber reinforced plastic (CFRP) including a reinforcing material that includes carbon fibers and a matrix that includes plastic. The structural member is formed by laminating a conductive sheet between prepregs of the carbon fiber reinforced plastic (CFRP). In this case, a cut surface of the structural member formed by cutting the structural member may be exposed on the inside in which fuel is stored.

Abstract: A joint (20) joins a plate member (26) with a preform (22), wherein an inclined part (28), which is inclined relative to a surface that is orthogonal to the direction in which a tensile load is applied to the plate member (26), is formed on a surface (25) that joins with the preform (22). Moreover, an indented part (38) corresponding to the shape of the inclined part (28) is formed on the preform (22) so that the inclined part (28) of the joint (20) is embedded into the indented part (38). The joint (20) is embedded in and bonded to the preform (22).