JP2016090259A - Method, program, device and system for calculating degree of fiber orientation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method, a program, a device, and a system for calculating a degree of fiber orientation capable of highly accurately calculating a degree of fiber orientation of a fiber composite material.SOLUTION: A profile acquisition section 301 acquires a profile representing a relationship between an angle around a center of a circular diffraction image generated by irradiating a fiber composite material with an X ray, and a diffraction intensity of the diffraction image. A crystal orientation degree calculation section 302 calculates a crystal orientation degree on the basis of the acquired profile. The profile acquisition section 301 acquires a profile of the fiber composite material in a state where reinforced fibers are aligned in one direction. The crystal orientation degree calculation section 302 calculates a crystal orientation degree of the fiber composite material on the basis of the acquired profile. A fiber orientation calculation section 303 calculates a fiber orientation degree of the fiber composite material on the basis of the crystal orientation degree.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fiber orientation degree calculation method, a fiber orientation degree calculation program, a fiber orientation degree calculation device, and a fiber orientation degree calculation system that calculate a fiber orientation degree of a fiber composite material.

  A fiber composite material in which a reinforced fiber such as carbon fiber and a resin are combined is being developed as a lightweight and excellent physical property in various fields such as automobiles and aircraft. The orientation state of the fibers inside the fiber composite material greatly affects the mechanical properties. Therefore, in order to further improve the performance of the fiber composite material, it is important to control the orientation state of the fibers.

  On the other hand, depending on the method of molding the fiber composite material, the fiber orientation state may not be sufficiently controlled. For example, in the case of a flat plate produced by injection molding, the fiber orientation differs between the surface and the inside of the plate. In press molding, fibers are oriented in the flow direction, but this orientation state changes depending on molding conditions (temperature, pressure, time).

  Therefore, when molding a member having a complicated three-dimensional shape such as a rib by injection molding or press molding, the fiber orientation may not be controlled. For this reason, in a complicated three-dimensional shape portion, the mechanical physical properties fluctuate due to the disorder of the fiber orientation, making it difficult to design the structural member. Of course, a part of the three-dimensional shape may be cut out and a physical property test may be performed, but it is generally difficult to ensure a size sufficient for measuring the mechanical physical property.

  On the other hand, even if physical property tests are difficult, if the mechanical properties can be calculated from the fiber orientation, the speed of optimization of the molding conditions can be increased, leading to the development of a high-performance fiber composite material. Image analysis methods (for example, Patent Document 1), X-ray CT methods (for example, Patent Document 2), and X-ray diffraction methods (for example, Non-Patent Document 1) are used as methods for examining the fiber orientation of the fiber composite material. is there.

JP 2012-246428 A JP 2010-91330 A

Kei Takeda et al., Molding, Vol. 1, P88 (1989)

  However, in the image analysis method described in Patent Document 1, since only one cross section of the sample is observed, the fiber orientation state of the entire sample cannot be grasped. In order to grasp the fiber orientation state of the entire sample, it is necessary to observe the cross section by repeating polishing and observation, but there is a problem that it is an enormous work.

  Further, in the X-ray CT method described in Patent Document 2, fiber orientation is captured using X-ray CT, but binarization processing that separates fibers and resin is required in the course of image analysis. In the binarization process, the determination of binarization differs depending on the worker, and as a result, there is a problem that the fiber orientation degree changes depending on the worker.

  In the X-ray diffraction method described in Non-Patent Document 1, the orientation of fibers is evaluated using a minute sample. For this reason, the fiber orientation degree of a practically sized molded product cannot be calculated.

  The present invention has been made in view of the above circumstances, a fiber orientation degree calculation method, a fiber orientation degree calculation program, a fiber orientation degree calculation device, and a fiber orientation degree capable of calculating the fiber orientation degree of a fiber composite material with high accuracy. It is an object to provide a calculation system.

The present invention has the following aspects.
[1] A first relationship between an angle around the center of a circular diffraction image generated by irradiating the first fiber composite material containing reinforcing fibers with X-rays and the diffraction intensity of the diffraction image at the angle. Based on the first procedure for obtaining the profile of the first and the first profile obtained in the first procedure, a first crystal orientation degree that is a crystal orientation degree of the first fiber composite material is calculated. A second procedure, an angle around the center of a circular diffraction image generated by irradiating the second fiber composite material including reinforcing fibers aligned in one direction with X-rays, and a diffraction image at the angle; Based on the third procedure for obtaining the second profile showing the relationship with the diffraction intensity of the second and the second profile obtained in the third procedure, the crystal orientation degree of the second fiber composite material Calculate a second degree of crystal orientation Based on the fourth procedure, the first crystal orientation degree calculated in the second procedure, and the second crystal orientation degree calculated in the fourth procedure, the first fiber composite And a fifth procedure for calculating the fiber orientation degree of the material.

[2] A first relationship between an angle around the center of a circular diffraction image generated by irradiating the first fiber composite material containing reinforcing fibers with X-rays and a diffraction intensity of the diffraction image at the angle. Based on the first procedure for obtaining the profile of the first and the first profile obtained in the first procedure, a first crystal orientation degree that is a crystal orientation degree of the first fiber composite material is calculated. A second procedure, an angle around the center of a circular diffraction image generated by irradiating the second fiber composite material including reinforcing fibers aligned in one direction with X-rays, and a diffraction image at the angle; Based on the third procedure for obtaining the second profile showing the relationship with the diffraction intensity of the second and the second profile obtained in the third procedure, the crystal orientation degree of the second fiber composite material Calculate a second degree of crystal orientation Based on the fourth procedure, the first crystal orientation degree calculated in the second procedure, and the second crystal orientation degree calculated in the fourth procedure, the first fiber composite The fiber orientation degree calculation program which makes a control part perform the 5th procedure which calculates the fiber orientation degree of material.

[3] A first relationship between an angle around the center of a circular diffraction image generated by irradiating the first fiber composite material containing reinforcing fibers with X-rays and the diffraction intensity of the diffraction image at the angle. First profile acquisition means for acquiring the first profile, and first crystal orientation that is a crystal orientation degree of the first fiber composite material based on the first profile acquired by the first profile acquisition means Around the center of a circular diffraction image generated by irradiating the second fiber composite material including the first fiber orientation degree calculating means for calculating the degree and the second fiber composite material including the reinforcing fibers aligned in one direction. Second profile acquisition means for acquiring a second profile indicating a relationship between an angle and the diffraction intensity of the diffraction image at the angle; and the second profile acquisition means acquired by the second profile acquisition means. Calculated by the second crystal orientation degree calculating means for calculating the second crystal orientation degree, which is the crystal orientation degree of the second fiber composite material, and the first crystal orientation degree calculating means. A fiber orientation degree for calculating a fiber orientation degree of the first fiber composite material based on the first crystal orientation degree and the second crystal orientation degree calculated by the second crystal orientation degree calculating means. And a fiber orientation degree calculating device.

[4] A fiber orientation degree calculation system in which an X-ray diffractometer and a fiber orientation degree calculator are connected, and the fiber orientation degree calculator is configured to irradiate a first fiber composite material including reinforcing fibers with X-rays. First profile acquisition means for acquiring, from the X-ray diffractometer, a first profile indicating a relationship between an angle around the center of a circular diffraction image generated by the operation and a diffraction intensity of the diffraction image at the angle And a first crystal orientation degree calculation for calculating a first crystal orientation degree which is a crystal orientation degree of the first fiber composite material based on the first profile acquired by the first profile acquisition means. And an angle around the center of a circular diffraction image generated by irradiating the second fiber composite material containing reinforcing fibers aligned in one direction with X-rays, and the diffraction intensity of the diffraction image at the angle Based on the second profile acquired by the second profile acquisition means that acquires the second profile from the X-ray diffractometer and the second profile acquired by the second profile acquisition means, the second fiber A second crystal orientation degree calculating means for calculating a second crystal orientation degree which is a crystal orientation degree of the composite material; the first crystal orientation degree calculated by the first crystal orientation degree calculating means; A fiber orientation degree calculating means for calculating a fiber orientation degree of the first fiber composite material based on the second crystal orientation degree calculated by the second crystal orientation degree calculating means. Calculation system.

  According to the present invention, the fiber orientation degree of the fiber composite material can be calculated with high accuracy.

FIG. 5 is a block diagram showing an internal process of a fiber orientation degree calculation device 300. It is a figure which shows the diffraction image which appears by irradiating a X-ray to a fiber composite material. It is a figure which shows the one-dimensional orientation profile of the carbon fiber bundle aligned by 1 direction. It is a figure which shows the one-dimensional orientation profile of an orthogonal laminated body. It is a figure which shows the one-dimensional orientation profile of pseudo-isotropic material. It is a figure which shows the one-dimensional orientation profile of a perfect isotropic material. It is a figure which shows angle φ redefined. It is a flowchart which shows the calculation process of the fiber orientation degree f. 3 is a flowchart showing a calculation process of mechanical properties of a sample X. It is a figure which shows the prepreg in which the notch | incision was made | formed by the fixed space | interval. It is a figure for demonstrating the production method of a press molding material. It is a figure which shows sample T1 and sample T2. It is a figure which shows sample T4 and sample T5. It is a scatter diagram by which the tensile elasticity modulus and fiber orientation degree of samples T1-T5 were plotted. It is a figure which shows sample T6.

  Hereinafter, a fiber orientation degree calculation method, a fiber orientation degree calculation program, a fiber orientation degree calculation device, and a fiber orientation degree calculation system of this embodiment will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the internal processing of the fiber orientation degree calculation device 300. The fiber orientation degree calculation device 300 is connected to the X-ray diffraction device 100 and the physical property measurement device 200. The X-ray diffractometer 100 is an apparatus that irradiates a fiber composite material with X-rays and measures the X-ray diffraction intensity caused by crystals inside the fiber. The physical property measuring apparatus 200 is an apparatus for measuring mechanical physical properties (for example, tensile elastic modulus) of the fiber composite material.

  The controller 310 of the fiber orientation degree calculation apparatus 300 includes a processor such as a CPU (Central Processing Unit) and a memory that stores a program executed by the processor. Functions of the profile acquisition unit 301, the crystal orientation degree calculation unit 302, the fiber orientation degree calculation unit 303, the approximate expression calculation unit 305, and the physical property calculation unit 306 in the fiber orientation degree calculation device 300 are executed by the control unit 310. The control unit 310 may be hardware such as LSI (Large Scale Integration) or ASIC (Application Specific Integrated Circuit).

  The fiber composite material in the present embodiment is composed of reinforcing fibers and a matrix resin. Reinforcing fibers generally have crystals, and the crystals are oriented in the fiber axis direction. As the reinforcing fiber, it is preferable to use a fiber having excellent mechanical properties.

  In this embodiment, carbon fibers are used as an example of reinforcing fibers, but other reinforcing fibers may be used as long as they are excellent in mechanical properties. The carbon fiber may be obtained from any raw material such as pitch, rayon, or polyacrylonitrile, and is a high-strength type of low elastic modulus carbon fiber, medium high elastic carbon fiber, or ultra high elastic carbon fiber. Either is acceptable. Since the fiber orientation evaluation is not affected by the length of the fiber, continuous fibers or short fibers may be used. Therefore, a molded product obtained by injection molding of short fiber pellets may be used.

  The matrix may be either a thermosetting resin or a thermoplastic resin as long as it is resin-based. Thermoplastic resins include polyamide (nylon 6, nylon 66, etc.), polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate, polyamideimide, polysulfone, polyethersulfone, polyetheretherketone. , Polyetherimide, polystyrene, ABS, polyphenylene sulfide, liquid crystal polyester, a copolymer of acrylonitrile and styrene, and the like can be used. A mixture of these may also be used. Further, the thermoplastic resin may be a copolymer such as nylon 6 and nylon 66 copolymer nylon.

Next, _a method for obtaining the one-dimensional orientation profile Pa of the fiber composite material Ma to be measured will be described. As described above, crystals are generally present in reinforcing fibers. Graphite crystals exist in the carbon fibers used in the present embodiment. The c-axis of this graphite crystal is oriented perpendicularly to the fiber axis on average. That is, the carbon network surface is oriented in the fiber axis direction. Therefore, when the X-ray diffraction apparatus 100 irradiates the carbon fiber bundle in which the reinforcing fibers are aligned in one direction, a circular diffraction image (Debye ring) appears.

FIG. 2 is a diagram showing a diffraction image that appears by irradiating the fiber composite material with X-rays. The X-ray diffraction apparatus 100 irradiates the fiber composite material Ma with X-rays. Then, the X-ray diffractometer 100 detects the diffraction intensity (luminance) of light along the appearing diffraction image (Debye ring) using the X-ray sensor 110. Thus, one-dimensional orientation profile P _a fiber composite material Ma is obtained.

  Here, an axis perpendicular to the fiber direction A of the carbon fiber is defined as a y-axis, and an axis parallel to the fiber direction A is defined as a z-axis. The intersection of the y-axis and the z-axis is the Debye ring center point O, and the angle around the center point O from the y-axis is φ. When the carbon fibers are aligned in the direction A in FIG. 2, the diffraction intensity (luminance) peaks at a position P1 where φ = 0 ° and a position P2 where φ = 180 °.

  FIG. 3 is a diagram showing a one-dimensional orientation profile of carbon fiber bundles aligned in one direction (A direction). The vertical axis in FIG. 3 indicates the diffraction intensity I (φ), and the horizontal axis indicates the angle φ. As shown in FIG. 3, the one-dimensional orientation profile of the carbon fiber bundles aligned in the A direction has peaks at positions of φ = 0 ° and φ = 180 °.

  A one-dimensional orientation profile of a material whose reinforcing fiber orientation is unknown is expressed by superposition of the profiles shown in FIG. For example, FIG. 4 shows a case of a so-called orthogonal laminate in which a fiber composite material in which reinforcing fibers are aligned in the A direction and a fiber composite material in which reinforcing fibers are aligned in the direction orthogonal to A are stacked. As shown, a peak of diffraction intensity appears every 90 °.

  Further, in the case of a so-called pseudo-isotropic material laminated by shifting the fiber direction of the fiber composite material by 45 °, a peak appears every 45 ° as shown in FIG. In the case of the pulverized carbon fiber, that is, a completely isotropic material, as shown in FIG. 6, the one-dimensional orientation profile has a constant value over φ = 0 ° to 360 °.

  There are one-dimensional detection and two-dimensional detection as methods for detecting the diffraction intensity. In the case of one-dimensional detection, it is necessary to rotate the sample of the fiber composite material. In order to detect in a short time, high-intensity radiation light may be used. In the case of two-dimensional detection, there is no need to rotate the sample. If it is difficult to rotate the sample, such as a large molded product such as an automobile door panel, bonnet, or trunk, a two-dimensional detector may be used.

  X-rays applied to the fiber composite material from the X-ray diffraction apparatus 100 are absorbed according to the thickness of the sample of the fiber composite material. Experiments have shown that the thickness of the sample is preferably 0.01 mm or more and 50 mm or less. When the thickness of the sample is smaller than 0.01 mm, it is difficult to evaluate the orientation because a diffraction image sufficient to determine the peak of diffraction intensity cannot be obtained. When the thickness is larger than 50 mm, X-rays are absorbed by the sample, so that a diffraction image cannot be obtained and it is difficult to evaluate the orientation.

X-ray diffraction device 100, the one-dimensional orientation profile P _a of the detected fiber composite material Ma, is transmitted to fiber orientation calculation unit 300. Profile acquisition unit 301 of the fiber orientation calculation unit 300 acquires the one-dimensional orientation profile _{P a} transmitted from the X-ray diffraction apparatus 100.

Next, _a method for calculating the crystal orientation degree fa of the fiber composite material Ma to be measured will be described. Crystal orientation calculation unit 302, based on the one-dimensional orientation profile _{P a} obtained by the profile acquisition unit 301 calculates the degree of crystal orientation according to the procedure Hermans.

Specifically, when the angle φ is defined again as shown in FIG. 7, the crystal orientation calculation unit 302 uses the following (Equation 1) to calculate the orientation coefficient a of the fiber composite material Ma to be measured. calculate.

The crystal orientation calculation unit 302 uses the orientation coefficient a and following the equation (2), calculates the degree of crystal orientation f _a textile composite material Ma to be measured.

In the present embodiment, the fiber orientation degree is calculated from the calculated crystal orientation degree. Originally, the degree of orientation of reinforcing fibers aligned in one direction is the same value regardless of the type of reinforcing fibers. However, given by equation (2) is a crystalline orientation degree f _a, the degree of crystal orientation f _a varies greatly with how to make fibers.

For example, in FIG. 3, the peak position of the diffraction intensity I (φ) does not change depending on the type of reinforcing fiber, but the peak width differs. Therefore, in order to calculate the fiber orientation of the fiber composite material Ma of the measurement target from the degree of crystal orientation f _a is 1 direction in one direction fiber composite material Mb crystalline orientation degree f in a state of aligned drawn carbon fiber _It is necessary to calculate _b . Furthermore, the calculated degree of crystalline orientation f _b, it is necessary to use the correction of data when calculating the fiber orientation degree f of the fiber composite material Ma. By this correction, the fiber orientation degree of the fiber composite material can be calculated with high accuracy.

Next, a method of calculating the degree of crystal orientation f _b in one direction fiber composite material Mb state the carbon fibers were aligned in one direction. The unidirectional fiber composite material Mb is composed of the same carbon fiber and matrix resin as the fiber composite material Ma to be measured.

The X-ray diffractometer 100 irradiates the unidirectional fiber composite material Mb with X-rays and detects the X-ray diffraction intensity caused by crystals inside the fiber. This shows the relationship between the diffraction intensity angle phi and the X-ray I (phi), 1-dimensional orientation profile P _b in one direction fiber composite material Mb are obtained. The X-ray diffraction apparatus 100 transmits the one-dimensional orientation profile _Pb to the fiber orientation degree calculation apparatus 300.

Profile acquisition unit 301 of the fiber orientation calculation unit 300, a one-dimensional orientation profile _{P b} in one direction fiber composite material Mb, obtained from X-ray diffraction apparatus 100. Crystal orientation calculation unit 302, based on the one-dimensional orientation profile _{P b} obtained by the profile acquisition unit 301 calculates the degree of crystal orientation according to the procedure Hermans.

Specifically, when the angle φ is defined as shown in FIG. 7, the crystal orientation calculation unit 302 calculates the orientation coefficient b of the unidirectional fiber composite material Mb using the following (Equation 3).

In addition, the crystal orientation degree calculation unit 302 calculates the crystal orientation degree f _b of the unidirectional fiber composite material Mb using the orientation coefficient b and the following (Equation 4).

Next, a method for calculating the fiber orientation degree f of the fiber composite material Ma to be measured will be described. Fiber orientation calculation unit 303, the crystal is calculated by the orientation calculation unit 302 a based on the degree of crystal orientation f _a and the degree of crystal orientation f _b, the following equation (5) the fiber orientation degree f of the fiber composite material Ma with Is calculated.

  The fiber orientation degree calculation unit 303 transmits the calculated fiber orientation degree f of the fiber composite material Ma to the display unit 304. An operator can grasp the fiber orientation state of the fiber composite material Ma by checking the fiber orientation degree f displayed on the display unit 304.

FIG. 8 is a flowchart showing a calculation process of the fiber orientation degree f. The flowchart of FIG. 8 is executed by the control unit 310. First, the profile acquiring unit 301, a one-dimensional orientation profile _{P a} fiber composite material Ma, obtained from X-ray diffraction apparatus 100 (step S100). Then, the crystal orientation calculation unit 302, based on the one-dimensional orientation profile _{P a} obtained by the profile acquisition unit 301 calculates the degree of crystal orientation _{f a} textile composite material Ma (step S101). Degree of crystal orientation f _a is calculated based on the aforementioned equation (1) and (Equation 2).

Next, the profile acquiring unit 301, a one-dimensional orientation profile _{P b} in one direction fiber composite material Mb, obtained from X-ray diffraction apparatus 100 (step S102). Next, the crystal orientation degree calculation unit 302 calculates the crystal orientation degree f _b of the unidirectional fiber composite material Mb based on the one-dimensional orientation profile P _b acquired by the profile acquisition unit 301 (step S103). Crystalline orientation degree f _b is calculated based on the aforementioned equation (3) and (Equation 4).

Then, the fiber orientation calculation unit 303, based on the degree of crystal orientation _{f a} calculated by the degree of crystalline orientation calculation unit 302 and the degree of crystal orientation _{f b,} calculates the fiber orientation degree f (step S104). The fiber orientation degree f is calculated based on the above (Formula 5). By using a crystalline orientation degree f _b as a correction value, it is possible to calculate the fiber orientation degree f with high accuracy.

  The fiber orientation degree calculation unit 303 transmits the calculated fiber orientation degree f to the display unit 304. The display unit 304 displays the fiber orientation degree f received from the fiber orientation degree calculation unit 303 (step S105). The above is the overall flow of this flowchart.

As described above, the degree of crystal orientation calculation unit 302 calculates the degree of crystal orientation f _a textile composite material Ma, of one direction fiber composite material Mb a crystalline orientation degree f _b. The fiber orientation calculation unit 303, based on the degree of crystal orientation f _a and the degree of crystal orientation f _b, calculates the fiber orientation degree f of the fiber composite material Ma. Thereby, according to this embodiment, the fiber orientation degree of the fiber composite material can be calculated with high accuracy.

  Next, a method for calculating the mechanical properties of the sample X whose mechanical properties are unknown will be described. The mechanical properties are, for example, strength and elastic modulus for each mode of tension, compression, and bending. Although it is desirable to measure the mechanical properties of a sample by performing a test according to a standard such as JIS, the shape of the sample is not limited as long as the mechanical properties can be tested.

  The physical property measuring apparatus 200 measures the mechanical properties of a plurality of types of samples obtained under various conditions. Here, in order to increase the accuracy of the approximate expression described later, it is desirable to measure the mechanical properties of as many types of samples as possible. The physical property measuring apparatus 200 transmits the measured mechanical physical properties to the approximate expression calculating unit 305 in the fiber orientation degree calculating apparatus 300.

  On the other hand, the fiber orientation degree calculation unit 303 calculates the fiber orientation degrees f of a plurality of types of samples whose mechanical properties are measured according to the flowchart shown in FIG. Then, the approximate expression calculation unit 305 calculates an approximate expression indicating the relationship between the mechanical properties and the fiber orientation degree f based on the mechanical properties and the fiber orientation degree f of a plurality of types of samples. Specifically, the approximate expression calculation unit 305 calculates an approximate expression by linear approximation, an Nth order function, an exponential function, or the like.

  Next, the fiber orientation degree calculation unit 303 calculates the fiber orientation degree f of the sample X whose mechanical properties are unknown according to the flowchart shown in FIG. The physical property calculation unit 306 calculates the mechanical physical property of the sample X based on the fiber orientation degree f of the sample X calculated by the fiber orientation degree calculation unit 303 and the approximate expression calculated by the approximate expression calculation unit 305.

  The physical property calculation unit 306 transmits the calculated mechanical properties of the sample X to the display unit 304. The operator can grasp the mechanical properties of the sample X by confirming the mechanical properties displayed on the display unit 304.

  FIG. 9 is a flowchart showing the calculation process of the mechanical properties of the sample X. The flowchart in FIG. 9 is executed by the control unit 310. First, the approximate expression calculation unit 305 acquires mechanical properties of a plurality of types of samples from the physical property measuring apparatus 200 (step S200). Next, the fiber orientation degree calculation unit 303 calculates the fiber orientation degree of each of the plurality of types of samples (step S201).

  Next, the approximate expression calculation unit 305 calculates an approximate expression based on the mechanical properties and the fiber orientation degree of a plurality of types of samples (step S202). Next, the fiber orientation degree calculation unit 303 calculates the fiber orientation degree f of the sample X whose mechanical properties are unknown (step S203). Then, the physical property calculation unit 306 calculates the mechanical physical properties of the sample X based on the fiber orientation degree f of the sample X and the approximate expression (step S204).

  The physical property calculation unit 306 transmits the calculated mechanical properties of the sample X to the display unit 304. The display unit 304 displays the mechanical properties of the sample X received from the property calculation unit 306 (step S205). The above is the overall flow of this flowchart.

  As described above, the approximate expression calculation unit 305 calculates an approximate expression indicating the relationship between the mechanical properties and the fiber orientation degree. In addition, the physical property calculation unit 306 calculates the mechanical physical property of the sample whose mechanical physical property is unknown using the calculated approximate expression. Thus, according to the present embodiment, it is possible to predict the physical properties of a part having a complicated shape that cannot measure the mechanical physical properties based on the degree of fiber orientation.

  The X-ray diffraction apparatus 100, the physical property measurement apparatus 200, and the fiber orientation degree calculation apparatus 300 are separate apparatuses, but the present embodiment is not limited to this. For example, the X-ray diffraction apparatus 100 and the physical property measurement apparatus 200 may be incorporated in the fiber orientation degree calculation apparatus 300.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

In this example, carbon fibers (manufactured by Mitsubishi Rayon Co., Ltd., product name: TR50S15L, 12,000 fibers, density 1.82 g / cm ² ) are arranged in a unidirectional plane so that the basis weight is 72.0 g / m ^2. A carbon fiber sheet is used. By laminating a resin film (nylon 6, manufactured by Ube Industries, product name: UBE1013B) having a basis weight of 45.6 g / m ^{2 on} both surfaces of the carbon fiber sheet, a laminate is created.

The laminate is passed through a calender roll heated to 200 ° C. to 280 ° C. a plurality of times, and a resin film is melt impregnated into a carbon fiber sheet to produce a prepreg. The prepared prepreg had a thickness of 120 μm, a basis weight of 145.0 g / m ² , and a fiber deposition content (Vf) of 48.0%.

  Next, creation of the unidirectional material 21 will be described. First, 8 sheets of prepregs cut to 295 mm length and 295 mm width are prepared. After the eight prepregs are laminated so as to be in one direction (0 ° direction), the laminate is partially welded with an ultrasonic welding machine (product name: 2000LPt, manufactured by Nippon Emerson Co., Ltd.). Created.

  The prepared laminate is placed in the center of a stamping mold with a length of 300 mm and a width of 300 mm, and a heating plate is put into a press machine preheated to 250 ° C., and heated and pressurized at a pressure of 0.30 MPa for 10 minutes. . Thereafter, the laminate is put into a press machine preheated to 30 ° C., and cooled and pressurized at a pressure of 1.0 MPa for 3 minutes. By these processes, a unidirectional material 21 having a thickness of 1 mm is produced.

  Next, creation of the pseudo isotropic material 22 will be described. First, a prepreg cut to 1240 mm × 940 mm is prepared. This prepreg is cut at regular intervals as shown in FIG. 10 by a cutting plotter (product name: L-2500, manufactured by Rezac Co., Ltd.). The incision 10 exists outside the region within 10 mm from the end of the prepreg.

Here, the length Lf of the carbon fiber 11 is 25.0 mm (constant), the average cut length Lc is 42.4 mm, and the angle θ between the cut 10 and the carbon fiber 11 is 45 °, and the cut is made into the prepreg. Processing is applied. The prepreg that has been cut is referred to as a cut prepreg. The total length La of the cutting length per 1 m ² in the cutting prepreg is 56.6 m.

  Next, 16 cut prepregs are prepared. The 16 cut prepregs are laminated with the direction of the fiber axis changed by 45 ° such that the fiber axis direction is [0 ° / 45 ° / 90 ° / −45 °]. Thereafter, the laminated 16 cut prepregs are partially welded with an ultrasonic welding machine (product name: 2000LPt, manufactured by Nippon Emerson Co., Ltd.), thereby forming a laminate.

  The prepared laminate is placed in the center of a 1250 mm vertical and 950 mm horizontal stamping mold, and the heating panel is put into a press machine preheated to 250 ° C. and heated and pressurized at a pressure of 0.30 MPa for 10 minutes. . Thereafter, the laminate is put into a press machine preheated to 130 ° C., and cooled and pressurized at a pressure of 1.0 MPa for 3 minutes. By these processes, a pseudo isotropic material 22 is created.

  Next, creation of the press molding material 23 will be described. First, two quasi-isotropic materials 22 cut to a length of 290 mm and a width of 200 mm are prepared. By laminating these two pseudo isotropic materials 22, a laminate 20 is created. The produced laminate 20 is preheated for 10 minutes with an IR heater at 380 ° C. And as FIG. 11 shows, the laminated body 20 is arrange | positioned in the center of the stamping type | mold 30 of length 300mm and width 300mm. Thereafter, the laminated body 20 is put into a press machine in which a heating plate is preheated to 170 ° C., and is pressurized at a pressure of 10 MPa for 2 minutes. By these processes, a press molding material is created. By pressing, the laminate 20 flows 50 mm to the left and 50 mm to the right. As a result, a press molding material 23 having a length of 300 mm and a width of 300 mm is produced.

  The sample T1 of the unidirectional material (0 ° direction) is cut out from the center of the unidirectional material 21 so as to have a length of 250 mm and a width of 25 mm, as shown in FIG. The long side direction of the sample T1 is parallel to the fiber direction A of the outermost layer.

  As shown in FIG. 12, the sample T2 of the unidirectional material (90 ° direction) is cut out from the center of the unidirectional material 21 to have a size of 250 mm in length and 25 mm in width. The long side direction of the sample T2 is perpendicular to the fiber direction A of the outermost layer. Note that the sample T1 and the sample T2 are not cut out from one unidirectional material 21, but are cut out from separate unidirectional materials 21.

  A sample T3 of the pseudo-isotropic material 22 is cut out to have a length of 250 mm and a width of 25 mm. The position where the sample T3 is cut out may be any position. Note that the long side direction of the sample T3 is parallel to the fiber direction A of the outermost layer.

  A sample T4 of the press-molding material 23 is cut out from the center of the press-molding material 23 so as to have a length of 250 mm and a width of 25 mm, as shown in FIG. Note that the long side direction of the sample T4 is parallel to the fiber direction A of the outermost layer. The sample T4 is referred to as a press-molded charge unit.

  As shown in FIG. 13, the sample T5 of the press-molding material 23 is cut out from the press-molding material 23 in a region where the laminate 20 is not arranged before pressing so as to have a size of 250 mm in length and 25 mm in width. It is. The long side direction of the sample T5 is parallel to the fiber direction A of the outermost layer. The sample T5 is referred to as a press-molding fluidizing portion.

Tabs are attached to both ends in the long side direction of the samples T1 to T5 cut out as described above, and the physical property measuring apparatus 200 measures the tensile elastic modulus of the samples T1 to T5. According to the measurement results, the tensile modulus of sample T1 is 106.2 GPa, the tensile modulus of sample T2 is 6.5 GPa, the tensile modulus of sample T3 is 35.0 GPa, the tensile modulus of sample T4 is 29.9 GPa, The tensile elastic modulus of Sample T5 was 37.2 GPa. These calculation results are shown in Table 1.

  Next, the X-ray diffraction apparatus 100 calculates the fiber orientation degree of the samples T1 to T5. In this embodiment, as the X-ray diffraction apparatus 100, a rotating counter-cathode X-ray generator (product name: TTR-III, manufactured by Rigaku Corporation) is used. The X-ray source is CuKα ray (Ni filter), and the output is 50 kW-300 mA (= 15 W). The detector is a NaI scintillation counter with 2θ = 25.4 °. A fiber sample stage is used as an attachment. The scanning range is 0 ° to 360 °, the scanning speed is 45 ° / min, and the sampling width is 0.36 °. The beam diameter is 3 mm.

  The X-ray diffraction apparatus 100 measures the one-dimensional orientation profile of the samples T1 to T5. Moreover, the fiber orientation degree calculation apparatus 300 calculates | requires the crystal orientation degree of the samples T1-T5 based on the one-dimensional profile of the samples T1-T5 measured by the X-ray diffraction apparatus 100.

That is, the fiber orientation degree calculation device 300 calculates the orientation coefficient a of the samples T2 to T5 using the above-described (Equation 1). The fiber orientation calculation unit 300, based on the orientation coefficient a sample T2 to T5, and calculates the degree of crystal orientation _{f a} sample T2 to T5 with the above-described (Equation 2).

Further, the fiber orientation degree calculation device 300 calculates the orientation coefficient b of the sample T1 using the above-described (Equation 3). The fiber orientation calculation unit 300, based on the orientation coefficient b of the sample T1, and calculates the degree of crystal orientation f _b of the sample T1 using the aforementioned equation (4). According to these calculation results, the degree of crystal orientation _{f b} is 0.56 for sample T1, the degree of crystal orientation _{f a} sample T2 is -0.56, the degree of crystal orientation _{f a} 0.02 sample T3, sample T4 the degree of crystalline orientation _{f a} -0.05, degree of crystal orientation _{f a} sample T5 was 0.20. These calculation results are shown in Table 1 described above.

The fiber orientation calculation unit 300, based on the degree of crystal orientation _{f b} of the crystal orientation degree _{f a} and sample T1 samples T2 to T5, the fiber orientation degree f of the sample T1~T5 using the above-described (Equation 5) Is calculated. According to these calculation results, the fiber orientation degree f of sample T1 is 1.00, the fiber orientation degree f of sample T2 is -1.00, the fiber orientation degree f of sample T3 is 0.03, and the fiber orientation degree of sample T4. The degree f was -0.08, and the fiber orientation degree f of Sample T5 was 0.36. These calculation results are shown in Table 1 described above.

FIG. 14 is a scatter diagram in which the tensile elastic modulus and fiber orientation degree of samples T1 to T5 are plotted. In FIG. 14, the horizontal axis (x axis) is the fiber orientation degree, and the vertical axis (y axis) is the tensile elastic modulus. The fiber orientation degree calculation device 300 calculates the approximate expression shown in FIG. 14 based on the tensile modulus of elasticity and the fiber orientation degree of samples T1 to T5 shown in Table 1. Specifically, the approximate expression shown in the following (Expression 6) was calculated.

  Next, the validity of the calculated approximate expression is verified. The fluid part of the press molding originally has no fiber, and since the fiber flows and fills from the charge part, the state of the fiber is complicated. The tensile elastic force of the sample T5 described above is the tensile elastic force in the A direction (vertical direction in FIG. 13) in the fluidized portion. On the other hand, using the calculated approximate expression of (Equation 6), the tensile elastic force in the direction perpendicular to the A direction (the left-right direction in FIG. 13) in the flow part is calculated, and whether the calculation result is appropriate or not. Validate.

Specifically, the fiber orientation degree calculation apparatus 300 shifts the one-dimensional profile of the sample T5 by 90 ° to the minus side, thereby causing a one-dimensional profile in the direction perpendicular to the A direction (the left-right direction in FIG. 13) in the fluidized part. Is calculated. And the fiber orientation degree calculation apparatus 300 calculates | requires the fiber orientation degree f using (Formula 1)-(Formula 5). According to this calculation result, the degree of crystal orientation _{f a} direction perpendicular to the direction A of the flow section (horizontal direction in FIG. 13) is -0.20, the fiber orientation degree f was -0.36.

  The fiber orientation degree calculating apparatus 300 calculates the tensile elastic modulus by substituting x = −0.36 into the approximate expression shown in (Expression 6). According to this calculation result, the tensile elastic modulus was 17.2 GPa.

  On the other hand, the sample T6 of the press molding material 23 is cut out from the left end of the press molding material 23 so as to have a length of 50 mm and a width of 25 mm, as shown in FIG. Tabs are attached to both ends in the long side direction of the sample T6, and the physical property measuring apparatus 200 measures the tensile elastic modulus of the sample T6. The tensile elastic modulus of the sample T6 is the tensile elastic modulus in the direction orthogonal to A shown in FIG.

  According to the measurement results, the tensile modulus of the sample T6 was 17.7 GPa. The calculated tensile modulus (17.2 GPa) is substantially equivalent to the measured tensile modulus (17.7 GPa). Therefore, the approximate expression calculated in this embodiment is appropriate.

  As described above, according to this embodiment, the fiber orientation degree of the fiber composite material can be calculated with high accuracy. Moreover, according to this embodiment, the mechanical physical property of the part of a complicated shape which cannot measure a mechanical physical property can be calculated based on a fiber orientation degree.

(Comparative Example 1)
In Comparative Example 1, an attempt was made to calculate the fiber orientation degree and the tensile elastic modulus using an X-ray CT apparatus. First, a sample T7 of a press molding material is cut out from the fluidized part of the press molding so as to have a length of 20 mm and a width of 10 mm. The long side direction of the sample T7 is parallel to the fiber direction A of the outermost layer.

  As an X-ray CT apparatus, TDM1000Sμ manufactured by Yamato Scientific is used. The reconstruction pixel size is 0.004 mm. From the image obtained by the X-ray CT apparatus, processing for separating fibers and resin and extracting only the fibers was performed using image analysis software manufactured by Ratok Engineering System.

  However, the criteria for judging fibers differ depending on the operator, and it is difficult to calculate the degree of fiber orientation. For this reason, in this comparative example 1, the necessity of creating an evaluation procedure that does not depend on the worker has arisen as a new problem.

(Comparative Example 2)
In Comparative Example 2, an attempt was made to calculate the fiber orientation degree and the tensile modulus by an image analysis method. Similar to Comparative Example 1, a sample T7 having a length of 20 mm and a width of 10 mm is cut out from the fluidized part of press molding. The operator mirror-polished sample T7 and observed it with a microscope using a lens of about 100 to 500 times.

  However, it cannot be determined that one cross section of the sample T7 is a cross section representing the sample T7. For this reason, it is necessary to grasp the entire sample T7 by repeating polishing and observation, but this is an enormous work for the operator. Therefore, in this comparative example 2, it was difficult to calculate the fiber orientation degree.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 100 X-ray-diffraction apparatus 200 Physical property measuring apparatus 300 Fiber orientation degree calculation apparatus 301 Profile acquisition part 302 Crystal orientation degree calculation part 303 Fiber orientation degree calculation part 304 Display part 305 Approximation formula calculation part 306 Physical property calculation part 310 Control part

Claims (12)

A first profile showing a relationship between an angle around the center of a circular diffraction image generated by irradiating the first fiber composite material containing reinforcing fibers with X-rays and a diffraction intensity of the diffraction image at the angle. A first procedure to acquire;
A second procedure for calculating a first degree of crystal orientation, which is a degree of crystal orientation of the first fiber composite material, based on the first profile obtained in the first procedure;
The relationship between the angle around the center of the circular diffraction image generated by irradiating the second fiber composite material including the reinforcing fibers aligned in one direction with X-rays and the diffraction intensity of the diffraction image at the angle A third procedure for obtaining a second profile indicating
A fourth procedure for calculating a second crystal orientation degree, which is a crystal orientation degree of the second fiber composite material, based on the second profile acquired in the third procedure;
Based on the first crystal orientation degree calculated in the second procedure and the second crystal orientation degree calculated in the fourth procedure, the fiber orientation degree of the first fiber composite material is determined. A fifth procedure to calculate,
A fiber orientation degree calculation method.   The fiber orientation according to claim 1, wherein in the fifth procedure, a fiber orientation degree of the first fiber composite material is calculated based on a ratio between the first crystal orientation degree and the second crystal orientation degree. Degree calculation method. When the angle is φ and the diffraction intensity is I (φ), the orientation coefficient a of the first fiber composite material and the first crystal orientation degree are based on the following (Formula 1) to (Formula 5). The fiber orientation degree according to claim 2, wherein f _a , the orientation coefficient b of the second fiber composite material, the second crystal orientation degree f _b, and the fiber orientation degree f of the first fiber composite material are calculated. Calculation method.

  The fiber orientation degree calculation method according to claim 1, wherein the reinforcing fiber included in the first fiber composite material is the same substance as the reinforcing fiber included in the second fiber composite material.   The fiber orientation degree calculation method according to claim 4, wherein the first fiber composite material and the second fiber composite material use carbon fibers as reinforcing fibers. The first fiber composite material and the second fiber composite material include a resin,
The fiber orientation degree calculation method according to claim 4, wherein the resin contained in the first fiber composite material is the same substance as the resin contained in the second fiber composite material.   6th which calculates the approximate expression which shows the relationship between a fiber orientation degree and a mechanical physical property based on the calculation result of the fiber orientation degree of multiple types of fiber composite material, and the measurement result of the mechanical physical property of the said multiple types of fiber composite material The fiber orientation degree calculation method according to claim 1, further comprising:   A seventh procedure for calculating mechanical properties of the first fiber composite material based on the approximate expression calculated in the sixth procedure and the fiber orientation degree calculated in the fifth procedure; The fiber orientation degree calculation method according to claim 7. A first profile showing a relationship between an angle around the center of a circular diffraction image generated by irradiating the first fiber composite material containing reinforcing fibers with X-rays and a diffraction intensity of the diffraction image at the angle. A first procedure to acquire;
A second procedure for calculating a first degree of crystal orientation, which is a degree of crystal orientation of the first fiber composite material, based on the first profile obtained in the first procedure;
The relationship between the angle around the center of the circular diffraction image generated by irradiating the second fiber composite material including the reinforcing fibers aligned in one direction with X-rays and the diffraction intensity of the diffraction image at the angle A third procedure for obtaining a second profile indicating
A fourth procedure for calculating a second crystal orientation degree, which is a crystal orientation degree of the second fiber composite material, based on the second profile acquired in the third procedure;
Based on the first crystal orientation degree calculated in the second procedure and the second crystal orientation degree calculated in the fourth procedure, the fiber orientation degree of the first fiber composite material is determined. A fifth procedure to calculate,
Is a fiber orientation degree calculation program for causing the control unit to execute. A first profile showing a relationship between an angle around the center of a circular diffraction image generated by irradiating the first fiber composite material containing reinforcing fibers with X-rays and a diffraction intensity of the diffraction image at the angle. First profile acquisition means for acquiring;
First crystal orientation degree calculating means for calculating a first crystal orientation degree that is a crystal orientation degree of the first fiber composite material based on the first profile acquired by the first profile acquisition means; ,
The relationship between the angle around the center of the circular diffraction image generated by irradiating the second fiber composite material including the reinforcing fibers aligned in one direction with X-rays and the diffraction intensity of the diffraction image at the angle Second profile acquisition means for acquiring a second profile indicating:
Second crystal orientation degree calculating means for calculating a second crystal orientation degree that is a crystal orientation degree of the second fiber composite material based on the second profile acquired by the second profile acquiring means; ,
Based on the first crystal orientation degree calculated by the first crystal orientation degree calculating means and the second crystal orientation degree calculated by the second crystal orientation degree calculating means, the first crystal orientation degree is calculated based on the first crystal orientation degree calculated by the first crystal orientation degree calculating means. A fiber orientation degree calculating means for calculating the fiber orientation degree of the fiber composite material;
A fiber orientation degree calculation device. A fiber orientation degree calculation system in which an X-ray diffractometer and a fiber orientation degree calculator are connected,
The fiber orientation degree calculating device is:
A first profile showing a relationship between an angle around the center of a circular diffraction image generated by irradiating the first fiber composite material containing reinforcing fibers with X-rays and a diffraction intensity of the diffraction image at the angle. First profile acquisition means for acquiring from the X-ray diffractometer;
First crystal orientation degree calculating means for calculating a first crystal orientation degree that is a crystal orientation degree of the first fiber composite material based on the first profile acquired by the first profile acquisition means; ,
The relationship between the angle around the center of the circular diffraction image generated by irradiating the second fiber composite material including the reinforcing fibers aligned in one direction with X-rays and the diffraction intensity of the diffraction image at the angle A second profile acquisition means for acquiring from the X-ray diffractometer a second profile indicating:
Second crystal orientation degree calculating means for calculating a second crystal orientation degree that is a crystal orientation degree of the second fiber composite material based on the second profile acquired by the second profile acquiring means; ,
Based on the first crystal orientation degree calculated by the first crystal orientation degree calculating means and the second crystal orientation degree calculated by the second crystal orientation degree calculating means, the first crystal orientation degree is calculated based on the first crystal orientation degree calculated by the first crystal orientation degree calculating means. A fiber orientation degree calculating means for calculating the fiber orientation degree of the fiber composite material;
A fiber orientation degree calculation system. A mechanical property measuring device for measuring mechanical properties of the plurality of types of fiber composite materials;
The fiber orientation degree calculating device includes a fiber orientation degree of the plurality of types of fiber composite materials calculated by the fiber orientation degree calculating means, and a mechanical property of the plurality of types of fiber composite materials measured by the mechanical property measuring device. The fiber orientation degree calculation system according to claim 11, further comprising: an approximate expression calculating unit that calculates an approximate expression indicating a relationship between the fiber orientation degree and the mechanical properties based on the above.

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