JP3018936B2 - Method and apparatus for evaluating anisotropy of fiber composite material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for evaluating the anisotropy of a material by irradiating ultrasonic waves, and more particularly, to propagate a transverse wave in the direction of the anisotropic principal axis and the other principal axes. The present invention relates to a method and an apparatus for evaluating anisotropy of a material, which are evaluated from a difference in propagation speed.

[0002]

2. Description of the Related Art In general, in the case of materials such as fiber composite materials, crystal materials, rolled metal materials, and stretched rubber, the orientation of these fibers or crystals (molecules) and the anisotropy of physical properties caused by rolling or stretching. However, it is important to evaluate the anisotropy of this type of material because it affects the quality of the function and the strength of the structure when used.

[0003] By the way, the literature "Material" (J. Soc. M.)
at. Sci. Japan), Vol. 43, No48
4, pp1-11, Jan. In 1994), an ultrasonic wave propagating in a solid is converted into an elastic wave, and the propagation speed changes according to the elastic constant and density of anisotropic materials such as a fiber composite material and a crystal material. It has been described that methods for evaluating fiber content and distribution of oriented fibers or crystal grains have been successful.

[0004] The method of evaluating anisotropy based on the above-mentioned literature is based on, for example, as shown in FIG. 7 or FIG. for example a longitudinal wave of the sample fiber direction direction perpendicular to the (the principal axis X ₁₎ or fiber direction (the direction of the main axis X ₃₎
In this case, the evaluation is made only by the propagation velocity in one direction calculated from the time until the reflected wave returns (the passing time of the transmitted wave may be used) and the propagation distance (thickness in the propagation direction).

The evaluation method based on this idea can only evaluate the distribution state of fibers and crystal grains (how dense the fibers and crystal grains are). Therefore, the distribution of the orientation direction of the fibers in a material such as a uniaxial fiber composite,
That distribution of orientation angles of the fibers on a plane including the anisotropic spindle X ₁ that will be described later, can not be evaluated that capture the anisotropy in other words.

[0006]

[SUMMARY OF THE INVENTION Therefore, in general, when evaluating the anisotropy of the fiber composite as shown in FIG. 7, for example, as shown in FIG. 10, substantially parallel to the anisotropy main axis X ₁ such a sample surface Sa and polished, to observe the sample surface Sa microscopically targeted fibers direction (anisotropy direction of the main axis X ₁₎ and actual for each fiber orientation angle θ formed by the direction a of the fiber The method of checking is adopted.

That is, the orientation angle θ is observed for a predetermined number of fibers, and the orientation angle θ is formed into a histogram as shown in FIG. Then, the detected histogram is compared with a normal reference histogram, and the orientation angle distribution state in the fiber composite material is evaluated. In this case, the histograms may be compared artificially to determine, but in order to eliminate individual differences, the reference histogram and the detected histogram are determined by a computer such as a personal computer.

[0008] However, even with this method based on microscopic observation,
This is for observing only the orientation angle distribution of the surface of the fiber composite material, that is, only the mapping information of the fibers onto the sample surface, and cannot grasp the distribution characteristics of the orientation angle of the entire sample. That is, in the case of a material having anisotropy such as a fiber composite material, the fibers are oriented also in the directions of the main axes X ₂ and X ₃ other than the anisotropic main axis X _1. It is difficult to grasp the distribution state of the orientation angle obtained by integrating the planes parallel to the anisotropic principal axis of the oriented fiber.

Further, the above-mentioned method based on microscopic observation is a destructive inspection for polishing a sample surface, and has a drawback that it is not practical. An object of the present invention is to solve the above problems and to provide a technique for simply and non-destructively evaluating the overall anisotropy of a material having anisotropy.

[0010]

Prior to the completion of the present invention, it was studied to evaluate the anisotropy of the entire sample in a material having anisotropy due to a longitudinal wave of ultrasonic waves. However, it was found that the longitudinal wave of the ultrasonic wave did not change depending on the distribution state of the orientation angle of the fiber or the crystal grain even if it changed depending on the distribution state of the fiber or the crystal grain.

On the other hand, a material having anisotropy exhibits an extremely high Young's modulus in the anisotropic direction, and the larger the proportion of fibers or crystal grains shifted from the target anisotropic direction, the higher the Young's modulus. Become smaller. It has been found that the Young's modulus related to such anisotropic direction distribution is also closely related to the propagation velocity of the transverse wave component of the ultrasonic wave. Therefore, the present invention focuses on a transverse wave of an ultrasonic wave, and has devised the following configuration.

That is, the fiber composite material anisotropy evaluation apparatus according to claim 1, which solves the above-mentioned problem, is made of resin or metal.
A fiber composite material anisotropy evaluation device that evaluates the anisotropy of the fiber composite material by irradiating ultrasonic waves to the fiber composite material in which the fibers are dispersed. On the other hand, the ultrasonic transceiver in which the fiber composite material sample is installed on the test table so that the direction of the target anisotropy is substantially orthogonal, and the vibration direction of the transverse wave component of the ultrasonic wave generated in the sample are A speed measuring means for measuring two propagation velocities in a state in which the direction of the anisotropy is coincident and in a state in which the vibration direction is substantially orthogonal to the direction of the anisotropy; A speed difference calculating means for obtaining a speed difference, and a judging means for evaluating the anisotropy of the fiber composite material based on the speed difference obtained by the speed difference calculating means are provided.

Here, the anisotropic direction means the direction of the anisotropic principal axis. For example, in the case of a fiber composite material in which the fiber directions are aligned in a uniaxial direction, the fiber direction means the fiber direction. In a material in which the fiber direction is determined, the direction in which the material is reinforced is intended by two fiber directions. In addition, the transverse wave component of the ultrasonic wave refers to a transverse wave inevitably generated when the ultrasonic wave propagates through a solid, and a transverse wave emitted from an ultrasonic probe made exclusively for the transverse wave.

According to a second aspect of the present invention, the determination means has a memory in which a plurality of distribution characteristics indicating the anisotropic distribution state of the fiber composite material are previously written for each of the speed differences, The anisotropy of the material is evaluated by selecting a state characteristic corresponding to the speed difference obtained by the means from the memory.

[0015] The invention according to claim 3, said determination means, said
From the two propagation velocities detected by the velocity measuring means, calculate the average value.
From the average value, the fiber volume ratio of the fiber composite material is obtained, the speed difference obtained by the speed difference calculation means is corrected with the fiber volume ratio, and the state characteristic corresponding to the corrected speed difference is obtained. It is selected from memory.

[0016] The invention according to claim 4 is that the resin or metal
A anisotropy evaluation apparatus of the fibers by irradiating ultrasonic waves to the fiber composite material dispersed fiber composite to evaluate the anisotropy of the fiber composite, the target to the traveling axis of the ultrasonic wave irradiated The sample of the fiber composite material is placed on a test table of an ultrasonic transceiver so that the directions of the anisotropy are substantially orthogonal to each other, and the vibration direction of the transverse wave component of the ultrasonic wave generated in the sample and the anisotropic direction. Irradiating the sample with ultrasonic waves in a state in which the directions of the characteristics coincide with each other, and measuring the propagation speed thereof; and the vibration direction of the transverse wave component of the ultrasonic waves while maintaining the orthogonal relationship between the traveling axis and the anisotropic direction. Irradiating the sample with ultrasonic waves in a state substantially orthogonal to the direction of the anisotropy and measuring the propagation speed thereof, and calculating the difference between the measured two propagation speeds. The anisotropy of the fiber composite material was evaluated based on the evaluation.

[0017]

According to the first aspect of the present invention, the propagation speed of a transverse wave whose vibration direction substantially matches the anisotropic direction of the fiber composite material and a transverse wave whose vibration direction almost matches the anisotropic direction are determined. By comparison, the former is faster than the latter than the Young's modulus, which varies closely with the anisotropic directional distribution. Therefore, when the fiber composite material sample is placed on the test table so that the target anisotropic direction is substantially orthogonal to the traveling axis of the ultrasonic wave, and the sample is irradiated with ultrasonic waves, it vibrates in the anisotropic direction. The speed difference between the propagation speed of the shear wave whose direction almost matches and the propagation speed of the shear wave whose vibration direction almost matches the direction orthogonal to the direction of anisotropy changes according to the state of the directional distribution of anisotropy. . That is, the speed difference becomes larger as the anisotropic directions are better aligned, and the speed difference becomes smaller as the anisotropic directions are more uneven.

Accordingly, two propagation velocities, one in which the vibration direction of the transverse wave component of the ultrasonic wave generated in the sample matches the anisotropic direction, and the other in which the vibration direction is substantially orthogonal to the anisotropic direction, The anisotropy of the material can be evaluated based on the difference between the two propagation velocities measured by the measuring means and obtained by the speed difference calculating means and based on the speed difference obtained by the speed difference calculating means.

According to the second aspect of the present invention, the memory provided in the discriminating means has a plurality of state characteristics representing the anisotropic state of the material, for example, the anisotropic direction distribution, for each speed difference. The histogram is actually measured, and the data is written in a memory so that the data can be read at a speed difference. As a result, a certain state characteristic can be selected from the memory based on the speed difference obtained by the speed calculating means, and the anisotropy of the material is evaluated from the selected state characteristic.

[0020]

In the invention according to claim 3 , the determining means obtains the fiber volume fraction of the fiber composite material from the average value obtained by the average value calculating means, and obtains the fiber volume ratio by the speed difference calculating means. Correct the speed difference. Then, a state characteristic corresponding to the corrected speed difference is selected from the memory.
If the state characteristics are selected based on the speed difference corrected by the fiber volume ratio, the anisotropy can be evaluated regardless of the fiber volume ratio.

According to the fourth aspect of the present invention, first, a material sample is placed on a test table so that the target anisotropic direction is substantially orthogonal to the traveling axis of the ultrasonic wave. The state in which the vibration direction of the transverse wave component of the ultrasonic wave generated in the sample matches the direction of the anisotropy, and the vibration of the transverse wave component of the ultrasonic wave while maintaining the orthogonal relationship between the traveling axis and the anisotropic direction. So that the direction is substantially perpendicular to the anisotropic direction,
The relationship between the direction of the anisotropy of the sample and the traveling axis of the ultrasonic wave is relatively rotated around the traveling axis to adjust the two propagation velocities in each state. Thereafter, if the difference between the two propagation velocities is determined, the anisotropy of the sample can be evaluated.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus for evaluating anisotropy of a material according to the present invention will be described in detail. First Embodiment FIGS. 1 to 4 illustrate a material anisotropy evaluation apparatus including the first to third aspects of the present invention. FIG. 1 is a basic configuration diagram of the present apparatus. Sample 1 is composed of whiskers (crystal fibers), short fibers,
It is a fiber composite material in which long fibers are dispersed in a medium. The sample 1 is a test table 3 made of a reflective material so that the anisotropic principal axis X ₁ coincident with the fiber direction is orthogonal to the traveling axis U of the ultrasonic wave emitted from the transmitting / receiving ultrasonic probe 2. Installed in

The transmission / reception type ultrasonic probe 2 stops oscillating the ultrasonic wave according to a command from the ultrasonic transmitter / receiver 4, and
The electric pulse signal of the received reflected wave is transmitted to the ultrasonic transmitter / receiver 4 and is configured to be able to turn around the traveling axis U by 90 ° by driving means such as a motor. The turning operation of the transmitting / receiving ultrasonic probe 2 will be described in detail. As shown in FIG. 2A, the transmitting / receiving ultrasonic probe 2 emits an ultrasonic wave with respect to the anisotropic principal axis X ₁ of the sample 1. A state in which the vibration direction B of the transverse wave component generated when propagating in the sample substantially matches the traveling axis U
And as the vibration direction B while maintaining the orthogonal relation between anisotropy main axis X ₁ is illustrated in FIG. 2 (B), the match in the direction (the direction of the main axis X ₂₎ substantially perpendicular to the anisotropy main axis X ₁ It turns to the state where it did.

The ultrasonic transmission / reception type ultrasonic probe 2 may be instructed by the ultrasonic transmitter / receiver 4 to stop the oscillation of the ultrasonic wave and to turn the drive means, for example, by a personal computer system described later. However, it may be performed manually. The ultrasonic transceiver 4 shapes the received electric pulse signal and sends the shaped measurement pulse 4 a to the personal computer system 5. PC system 5
Comprises a speed measuring means 6, a speed difference calculating means 7, a judging means 8 and an average value calculating means 10 by a general arithmetic unit, data storage unit and program memory unit.

The speed measuring means 6 detects that the vibration direction B is as shown in FIG.
The state of (A) and intervals T (time) of each measurement pulse 4a to be input when the state FIG. 2 (B) and the propagation distance 2h more both propagation velocity V _x, calculates the V _y. The speed measuring means 6
The signals of the two propagation velocities V _x and V _y thus obtained are sent to the velocity difference calculating means 7 and the average value calculating means 10, respectively.
Speed difference is calculated calculating means speed difference in 7 V _x -V _y has an average value calculating means averages the _{10 (V x + V y)} / 2 is calculated. The average value may be any value as long as it is similar to this.

The signal indicating the speed difference V _x -V _y and the signal indicating the average value (V _x + V _y ) / 2 are sent to the judgment means 8. In the case of the present embodiment, the judging means 8 has a memory 9a in which a plurality of state characteristics indicating the anisotropic state of the sample are written in advance for each of the above speed differences. This state characteristic means, for each predetermined speed difference, here, for each of the four speed differences (I to IV), for example, the distribution of anisotropic direction angles, that is, in the case of a fiber composite material, the fiber orientation. Four histograms (FIGS. 3 (A) to 3
(D)). The histogram of FIG. 3 (A) is for the rank I with the largest speed difference, has the steepest distribution characteristic, and indicates that the distribution of the orientation angle is the best. FIG. 3 (B)
Is the one with the next best orientation angle distribution. Hereinafter, as the rank increases, the steepness of the histogram is attenuated, indicating that the distribution of the orientation angle is poor.

These histograms are written in the memory 9a. Thus, determination unit 8, the speed difference V _x -V _y at a speed difference calculating means is calculated, it is determined whether the computed speed difference V _x -V _y corresponds to any of the ranks, the The memory 9a is read and controlled at an address corresponding to the rank. The read histogram can be obtained as a graph by a display unit or a printing unit. If the capacity of the memory 9a allows, a more realistic histogram can be obtained by increasing the rank of the speed difference.

The apparatus for evaluating anisotropy of a material as described above operates as shown in the flowchart of FIG. First, as a preparation step, as shown in FIG. 1, the sample 1 is placed so as to be orthogonal to the anisotropic principal axis X _{1 of the} fiber and the traveling axis U of the ultrasonic wave emitted from the transmitting / receiving ultrasonic probe 2. Installed on the inspection table 3. Specifically, to prepare a sample 1 such as the thickness direction and the anisotropy main axis X ₁ for propagating an ultrasonic wave are orthogonal, the sample 1
Of collated for example the reference line indicating the direction of the anisotropic spindle X _1, it is placed oriented in the sample 1.

Next, the personal computer system 5 is operated to execute the flowchart of FIG. A start, the step S ₁ is executed, the personal computer system 5, so that the vibration direction B of the transverse wave component ultrasonic waves are irradiated in a state of almost consistent with anisotropic main axis X ₁ (fiber direction) of the sample 1 To
An instruction is made to turn the transmitting / receiving ultrasonic probe 2 around the traveling axis U, and the transmitting / receiving ultrasonic probe 2 is pressed against the surface of the sample 1 as shown in FIG.

Thereafter, in step S ₂ , an ultrasonic wave is irradiated, and a measuring pulse 4 a based on an electric pulse signal output from the transmitting / receiving ultrasonic probe 2 at that time is taken into the speed measuring means 6 and the measuring pulse 4 a measuring the shear wave propagation speed V _X than the distance. Then run the step S _3, instruction according to step S _1, i.e., advancing axis U and anisotropic main axis X
_While maintaining the orthogonal relationship of ₁ , the transmitting and receiving ultrasonic probe is performed so that the ultrasonic wave is emitted in a state where the vibration direction B of the transverse wave component is substantially orthogonal to the anisotropic principal axis X ₁ (fiber direction) of the sample 1. Child 2
2 is turned 90 ° around the traveling axis U, and FIG.
As shown in (B), the transmitting / receiving ultrasonic probe 2 is pressed against the surface of the sample 1.

Thereafter, step S according to step S _2
4 by applying ultrasonic waves to measure the shear wave propagation velocity V _y from the interval captures the measurement pulse 4a based on the electric pulse signal transmitting and receiving ultrasonic probe 2 to the speed measuring means 6.
Next, incorporation of the speed difference calculating means 7 and the propagation velocity V _x and V _y, obtaining the speed difference V _x -V _y by Step S _5.
The speed difference alone may determine the state of the anisotropic (corresponding to the invention of claim 1), wherein, as can be coped with the same system also has a different material thicknesses, executes Step S ₆ .

[0033] Step S ₆ is intended to the mean value calculating means 10 perform the arithmetic average of the propagation velocity V _x and V _y, the average value _{(V x + V y) /} 2 , the propagation distance of the ultrasonic wave, i.e. ultrasonic since sound waves is proportional to the thickness of the sample for the two main axis directions propagated, followed by dividing the speed difference by the average value at step S _7, the speed difference of the sample thickness obtained by the speed difference calculating means 10 (size ) Can be standardized. Step S ₇ is that, although it is performed at decision unit 8, may be added an operation means for performing a special step S ₇ is constitutively.

The memory 9 in the normalized speed difference D _V (hereinafter, referred to as the normalized speed difference D _V), the determination unit 8
It is converted to address data for a. Recognize the rank of the normalized speed difference D _V during this conversion, selects the corresponding histogram of FIG. 3 in the resulting address data (A) ~ (D) (Step S _8). As described above, in the first embodiment, there is a close relationship between the distribution state of the fiber orientation angle and the Young's modulus, and a close relationship between the propagation velocity of the transverse wave component of the ultrasonic wave and the Young's modulus. By doing so, we found that the difference in propagation speed between the shear wave whose vibration direction almost matched the fiber direction and the shear wave whose vibration direction almost matched the direction perpendicular to the fiber direction became a numerical value related to the orientation distribution in the fiber direction,
The distribution of the orientation angle of the fiber composite material is evaluated nondestructively.

Second Embodiment In a fiber composite material, a different fiber volume ratio is required depending on the application. In this case, a material having a large fiber volume ratio has a high propagation speed, and a material having a small fiber volume ratio has a low propagation speed. This relationship, propagation velocity V _X and the fiber direction perpendicular to the direction (major axis X of the fiber direction (direction of the anisotropic main axis X ₁₎
In the propagation velocity V _y direction ₂ or X ₃₎ may be increased or decreased at the same rate, but they are considered to change at a different rate.

Therefore, in the second embodiment, as shown in FIG. 5, attention is paid to the fact that the relationship between the fiber volume ratio and the average value (V _x + V _y ) / 2 is a linear function. The RAM 9b in which the linear function shown in FIG. 5 is written is added, and the speed difference V _x
The -V _y and corrects the fiber volume fraction Q. The coefficients a and b of the linear function are constants determined by the base material and the fiber.

FIG. 6 is a flowchart showing a case where the correction is made based on the fiber volume ratio. 6, step S ₉ is performed after step S ₇ of FIG. 4,
The fiber volume ratio Q corresponding to the average value (V _x + V _y ) / 2 is represented by R
This is a process of reading from the AM 9b. Read fiber volume fraction Q corrects the normalized speed difference D _V obtained in step S ₇ in step S _10. That is, the normalized speed difference D
Since _V is proportional to the fiber volume fraction Q, corrected D _V by the ratio fiber volume fraction as a reference for the read fiber volume fraction Q, and standard speed difference D _V 'after the correction. In step S ₁₁ subsequent to elect a histogram corresponding from the memory 9a converts the normalized speed difference D _V 'to the address. Thereby, the distribution state of the orientation angle in the fiber direction is evaluated.

The fiber volume ratio Q corresponding to the average value is:
The coefficients a and b of the linear function may be input to the determining means 8 in advance, and the average value may be calculated by substituting the average value into the linear function. By selecting a histogram based on the normalized speed difference corrected by the fiber volume ratio in this way, it is possible to evaluate anisotropy regardless of the fiber volume ratio, and without changing data etc. even for materials with different fiber volume ratios. The same system can be used, and the system can be simplified.

In each of the embodiments, the ultrasonic wave is reciprocated in the thickness direction of the sample. However, if a separate ultrasonic probe is used for transmission and reception, the ultrasonic wave can be calculated only by the propagation speed of the outward path. . Also, an ultrasonic probe that can irradiate only a transverse wave may be used. Furthermore, the speed difference can be determined as the difference between the two propagation speed with respect to the direction of the anisotropic main axis X ₁ and the spindle X _3.

[0040]

As described above, according to the first aspect of the present invention, the transverse wave whose vibration direction substantially coincides with the anisotropic direction of the material and the vibration direction substantially perpendicular to the anisotropic direction are obtained. By finding that the difference between the two propagation velocities with the matched shear wave is related to the goodness of the directional distribution of the anisotropy, the material has a simple structure that measures the ultrasonic propagation velocity and performs some calculations. Can be evaluated without destroying the material.

According to the second aspect of the present invention, a state characteristic such as a histogram representing the state of the directional distribution is selected based on the difference between the two propagation velocities. Can be evaluated by a graph instead of a simple numerical comparison between the comparison value expressing the numerical value and the speed difference.

According to the third aspect of the present invention, the speed difference of the speed difference calculating means relating to the anisotropic directional distribution is corrected by the fiber volume ratio. The same system can be used without any changes.

According to the fourth aspect of the present invention, the sample of the material is placed on the test table so that the target direction of the anisotropy is substantially orthogonal to the traveling axis of the ultrasonic wave. The anisotropy of the sample can be evaluated by a simple procedure that only calculates the difference in the propagation speed of the shear wave component.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a material anisotropic device according to a first embodiment that embodies the inventions of claims 1 to 3;

FIG. 2 shows the relationship between the anisotropic principal axis of the sample, the traveling axis of the ultrasonic wave, and the vibration direction of the shear wave in the first embodiment. FIG. 7B is an explanatory view of a state in which they match, and FIG. 8B is an explanatory view of a state in which the anisotropic principal axis of the sample and the vibration direction of the shear wave are substantially orthogonal.

FIG. 3 is a state characteristic showing the contents of a memory included in the determination means according to claims 1 to 5, showing a distribution state of an orientation angle in the case of a fiber composite material, and FIG.
(B) is the next best histogram, (C) is the next best histogram, and (D) is the lowest rank histogram. The vertical axis of each histogram represents the number of fibers, and the horizontal axis represents the orientation angle.

FIG. 4 is a flowchart showing the operation of the invention of claim 3;

FIG. 5 is a diagram showing an example of an R included in a determination means according to the present invention;
It is a graph which shows the content of AM, a vertical axis | shaft represents a fiber volume ratio and a horizontal axis | shaft represents an average value.

FIG. 6 is a flowchart showing a part of the operation of the invention according to claims 4 and 5;

FIG. 7 is an explanatory diagram of a fiber composite material evaluated in the present invention, where X ₁ , X ₂ , and X ₃ indicate three main axes of the fiber composite material.

FIG. 8 is an explanatory diagram showing a conventional method for evaluating the fiber content of a material and the distribution state of oriented fibers or crystal grains using ultrasonic waves.

FIG. 9 is an explanatory view showing a conventional method for evaluating the fiber content of a material and the distribution of oriented fibers or crystal grains using ultrasonic waves.

FIG. 10 is an explanatory diagram showing a conventional method for evaluating an orientation distribution using a microscope.

FIG. 11 is a histogram of an orientation distribution analyzed by the method of FIG.

[Explanation of symbols]

1 is a sample, 2 is a transmitting / receiving ultrasonic probe, 3 is a test table, 4 is an ultrasonic transceiver, 5 is a personal computer system, 6 is a speed measuring means, 7 is a speed difference calculating means, 8 is a determining means, 9a is a memory, 9b is a RAM, and 10 is an average value calculating means, and the same elements are denoted by the same reference numerals in each figure.

Claims (4)

(57) [Claims] 1. Fibers dispersed in resin or metal
An apparatus for evaluating anisotropy of a fiber composite material , which irradiates ultrasonic waves to the fiber composite material to evaluate anisotropy of the fiber composite material, wherein the anisotropy is set to be a target with respect to a traveling axis of the irradiated ultrasonic wave An ultrasonic transceiver in which the fiber composite sample is placed on the test table so that the directions of the properties are substantially orthogonal to each other, and the vibration direction of the transverse wave component of the ultrasonic wave generated in the sample is the same as the direction of the anisotropy. A velocity measuring means for measuring two propagation velocities in a state in which the vibrations coincide with each other and in which the vibration direction is substantially orthogonal to the anisotropic direction, and a velocity difference for obtaining a difference between the two propagation velocities detected by the velocity measuring means. An apparatus for evaluating anisotropy of a fiber composite material , comprising: calculation means; and determination means for evaluating the anisotropy of the fiber composite material based on the speed difference obtained by the speed difference calculation means. 2. The method according to claim 1, wherein the determining means includes a memory in which a plurality of state characteristics indicating a distribution of anisotropy of the fiber composite material measured in advance for each of the speed differences are written. The fiber composite material anisotropy evaluation device according to claim 1, wherein a state characteristic corresponding to the determined speed difference is selected from the memory, and the anisotropy of the fiber composite material is evaluated from the selected state characteristic. 3. The method according to claim 2, wherein the determining unit detects the speed by the speed measuring unit.
Issued an average value from the two propagation speed was, the average value calculated for fiber維体factor of the fiber composite, to correct the speed difference obtained in the speed difference calculating means with the fiber volume fraction, the 2. The apparatus according to claim 1, wherein the state characteristic corresponding to the corrected speed difference is selected from the memory. 4. Fibers dispersed in resin or metal
A fiber composite anisotropy evaluation device for irradiating a fiber composite material with ultrasonic waves to evaluate the anisotropy of the fiber composite material , wherein the anisotropy target is set with respect to the traveling axis of the irradiated ultrasonic wave. The sample of the fiber composite material is placed on the test table of the ultrasonic transceiver so that the directions of the properties are substantially orthogonal, and the direction of vibration of the transverse wave component of the ultrasonic wave generated in the sample and the direction of the anisotropy are set. Irradiating the sample with ultrasonic waves in a matched state and measuring the propagation velocity thereof; and maintaining the orthogonal relationship between the traveling axis and the anisotropic direction to change the vibration direction of the transverse wave component of the ultrasonic waves to the anisotropic direction. Irradiating the sample with ultrasonic waves in a state substantially orthogonal to the direction of the property, and measuring the propagation speed thereof, obtaining the difference between the measured two propagation speeds, and based on the difference between the two propagation speeds, anisotropy Review of fiber composite material characterized by evaluating the anisotropy of the composite material Method.