JP2005092718A - Method and program for dynamic analysis of composite material and device for dynamic analysis of composite material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quantitatively evaluate the relationship between the microscopic structures and dynamic properties of real complex and various composite materials. <P>SOLUTION: A specimen of a composite material is magnified using a microscope to acquire a microscopic image of the composite material (step S101). Once a two-dimensional finite-element model is created based on the microscopic image, a material constant for the composite material is set (step S102), and an analysis is performed using a finite-element method of analysis which has prior experimental results of the composite material to be analyzed (step S103). An S-S curve obtained by the analysis by the finite-element method is compared with an experimentally obtained S-S curve (step S104); when the curves do not match (step S104; No), the two-dimensional finite-element model created is modified (step S105). Using the two-dimensional finite-element model modified, the dynamic properties of the composite materials is evaluated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to analysis of mechanical properties of composite materials, and more specifically, composite materials capable of quantitatively evaluating the relationship between microscopic structures and mechanical properties for actual complex and diverse composite materials. The present invention relates to a mechanical analysis method and program, and a composite material mechanical analysis apparatus.

  In recent years, with the development of computers, methods for predicting and analyzing the mechanical properties of composite materials by computer simulation using approximate analysis methods have been put into practical use. Various analysis methods are used for computer simulation, and a typical analysis method using a finite element method is known. FIG. 13A is a conceptual diagram illustrating a microscopic image of a composite material. FIG. 13-2 is a conceptual diagram illustrating a method for creating a finite element model for a microscopic image disclosed in Patent Documents 1 to 3 below. FIG. 13C is a conceptual diagram illustrating a microscopic image of an actual more complicated and diverse composite material. In Patent Documents 1 to 3, the dispersibility of the second phase material 103 such as the particulate filler in the matrix phase 102 is quantified using a microscopic image of the composite material as shown in FIG. Has been disclosed (n is an integer).

Japanese Patent Laid-Open No. 9-180002 Japanese Patent Laid-Open No. 9-288689 JP-A-10-11613

  By the way, the above finite element model creation method is an effective method for a composite material having a simple structure in which the particulate filler is dispersed as the second phase material 103 in the matrix phase 102 as shown in FIG. . However, it is difficult to quantitatively evaluate the relationship between the microscopic structure and the mechanical properties for an actual more complicated and diverse composite material (for example, FIG. 13-3). Accordingly, the present invention has been made in view of the above, and it is a composite material that can quantitatively evaluate the relationship between the microscopic structure and the mechanical properties even for a complex material having an actual complicated and various structure. It is an object to provide a mechanical analysis method and program, and a composite material mechanical analysis apparatus.

  In order to achieve the above-described object, a mechanical analysis method for a composite material according to the present invention includes an image acquisition step for obtaining a microscopic image of a microscopic structure of a composite material composed of a matrix phase and a dispersed phase; A separation step of separating the mother phase portion and the dispersed phase portion of the microscopic image on the basis of a threshold value of the microscopic image, and the mother phase portion and the dispersed phase portion are divided by elements based on a plurality of finite element methods Further, by performing a finite element model creation step of modeling the microscopic image after the separation step into a two-dimensional finite element model, and performing a mechanical analysis of the composite material using the two-dimensional finite element model, And an analysis step for obtaining a parameter relating to the mechanical properties of the composite material.

  Further, the following composite material dynamic analysis program according to the present invention is based on an image acquisition procedure for obtaining a microscopic image of a microscopic structure of a composite material composed of a matrix phase and a dispersed phase, and a predetermined threshold. Separation procedure for separating the mother phase portion and the dispersed phase portion of the microscopic image, and the separation step so that the mother phase portion and the dispersed phase portion are divided by elements based on a plurality of finite element methods. A finite element model creation procedure for later modeling the microscopic image into a two-dimensional finite element model, and performing a mechanical analysis of the composite material using the two-dimensional finite element model. An analysis procedure for obtaining a parameter relating to characteristics is executed by a computer.

  In this mechanical analysis method of a composite material, a two-dimensional microscopic image in which a matrix phase and a dispersed phase are separated from a microscopic image of a composite material composed of a matrix phase and a dispersed phase on the basis of a predetermined threshold value. Create a visual image. Then, a dispersed phase and a parent phase included in the microscopic image are divided into at least a plurality of elements based on the finite element method to form a two-dimensional finite element model. With such a configuration, a two-dimensional finite element model reflecting the morphology information of the composite material can be created. And since the mechanical analysis by the finite element method is performed using such a two-dimensional finite element model, the microscopic structure and the mechanical characteristics of a complex material of an actual complex and various structure The relationship can be quantitatively evaluated. Further, according to the composite material dynamic analysis program, the above-described composite material dynamic analysis method can be realized using a computer. In the present specification, the program refers to a computer program.

  Further, the following composite material mechanical analysis method according to the present invention is characterized in that in the composite material mechanical analysis method, the microscopic image is modeled as a two-dimensional finite element by the uniform element. .

  Further, the composite material dynamic analysis program according to the present invention is characterized in that, in the composite material mechanical analysis program, the microscopic image is modeled as a two-dimensional finite element by the uniform element. .

  In this mechanical analysis method of a composite material, when creating a two-dimensional finite element model, the microscopic image is divided and modeled by elements based on a uniform finite element method. Thereby, it is possible to easily obtain the frequency distribution of the parameters relating to the principal strain, principal stress and other mechanical characteristics of the composite material. Further, according to the composite material dynamic analysis program, the above-described composite material dynamic analysis method can be realized using a computer.

  The composite material mechanical analysis method according to the present invention is the composite material mechanical analysis method, wherein the composite material has the same mechanical properties as those evaluated in the analysis step after the analysis step. And the analysis result using the two-dimensional finite element model are compared, and the two-dimensional finite element model is corrected based on the comparison result.

  Further, the composite material dynamic analysis program according to the present invention is the composite material mechanical analysis program, wherein the composite material has the same mechanical properties as those evaluated in the analysis procedure after the analysis step. And the analysis result using the two-dimensional finite element model are compared, and the two-dimensional finite element model is corrected based on the comparison result.

  In this composite material dynamic analysis method, for example, among the analysis methods such as uniaxial tensile analysis, compression analysis, or shear solution for the composite material, the two-dimensional finite analysis method is the same as the analysis method in which the experimental result exists. Analyze the mechanical properties of composite materials using element models. Then, the experimental result and the analysis result are compared, and the two-dimensional finite element model is corrected so that the difference between the two is within a predetermined range. As a result, an analysis result reflecting the behavior of the actual composite material can be obtained, so that the relationship between the microscopic structure and the mechanical property in the composite material having the actual complex and various structures can be quantitatively evaluated with higher accuracy. . Further, according to the composite material dynamic analysis program, the above-described composite material dynamic analysis method can be realized using a computer.

  Further, the following mechanical analysis method of the composite material according to the present invention is the above-described composite material mechanical analysis method, comparing an experimental result for the composite material with an analysis result using the two-dimensional finite element model, When the difference between the two is larger than a predetermined range, the two-dimensional finite element model is corrected in consideration of the three-dimensional form of the microscopic structure of the composite material.

  This mechanical analysis method of the composite material takes into consideration the three-dimensional form of the micro structure of the composite material in correcting the two-dimensional finite element model, and the two-dimensional finite element model so as to strengthen the connection of the matrix. To correct. As a result, an analysis result reflecting the behavior of the actual composite material can be obtained, so that the relationship between the microscopic structure and the mechanical property in the composite material having the actual complex and various structures can be quantitatively evaluated with higher accuracy. .

  Further, the following mechanical analysis method of the composite material according to the present invention is the above-described composite material mechanical analysis method, comparing an experimental result for the composite material with an analysis result using the two-dimensional finite element model, When the difference between the two is larger than a predetermined range, the material constant of the composite material is changed to modify the two-dimensional finite element model.

  This mechanical analysis method of a composite material corrects a two-dimensional finite element model by changing a material constant of the composite material when correcting the two-dimensional finite element model. As a result, even when dealing with a composite material whose material constant is unknown, an analysis result reflecting the behavior of the actual composite material can be obtained, so the microscopic structure and mechanical properties of the actual composite material The relationship can be quantitatively evaluated.

  Further, the following mechanical analysis method of the composite material according to the present invention is based on an analysis result using the two-dimensional finite element model or the modified two-dimensional finite element model in the composite material mechanical analysis method. A frequency distribution of at least a parameter relating to the mechanical characteristics of the matrix phase portion and a parameter relating to the mechanical characteristics of the dispersed phase portion is obtained.

  Further, the following composite material dynamic analysis program according to the present invention is based on an analysis result using the two-dimensional finite element model or the modified two-dimensional finite element model in the composite material mechanical analysis program, A frequency distribution of at least a parameter relating to the mechanical characteristics of the matrix phase portion and a parameter relating to the mechanical characteristics of the dispersed phase portion is obtained.

  The mechanical analysis method of this composite material is based on the analysis results using the two-dimensional finite element model or the modified two-dimensional finite element model. Obtain the frequency distribution of parameters related to characteristics. Thereby, durability, strength, and other mechanical characteristics of the composite material can be easily evaluated. Further, according to the composite material dynamic analysis program, the above-described composite material dynamic analysis method can be realized using a computer.

  Further, the composite material mechanical analysis method according to the present invention is characterized in that, in the composite material mechanical analysis method, an integrated distribution of parameters relating to the mechanical properties of the composite material is obtained from the function of the frequency distribution. And

  Further, the composite material dynamic analysis program according to the present invention is characterized in that, in the composite material mechanical analysis program, an integrated distribution of parameters relating to the mechanical properties of the composite material is obtained from the function of the frequency distribution. And

  This mechanical analysis method of a composite material obtains a frequency distribution of parameters relating to principal strain, principal stress and other mechanical properties in a matrix phase portion and a dispersed phase portion of the composite material, and from this, an integrated distribution of parameters relating to the mechanical properties. Ask for. Thereby, durability, strength, and other mechanical characteristics of the composite material can be more easily and accurately evaluated. Further, according to the composite material dynamic analysis program, the above-described composite material dynamic analysis method can be realized using a computer.

  Further, the following composite material mechanical analysis method according to the present invention is the composite material mechanical analysis method, wherein, in the separation step, the composite material exists between the matrix phase and the dispersed phase. The boundary region is also separated.

  This mechanical analysis method of the composite material further separates the boundary region existing between the matrix phase and the dispersed phase of the composite material, so that not only the composite material having a two-phase structure of the matrix phase and the dispersed phase, Even for composite materials composed of a plurality of phases, the relationship between the microscopic structure and the mechanical properties can be quantitatively evaluated. In addition, analysis results can be obtained in a state closer to the structure of a real composite material, so quantitative evaluation of the relationship between the microscopic structure and mechanical properties of a composite material with a complex and diverse structure is possible. it can.

  Further, the composite material dynamic analysis apparatus according to the present invention provides a microscopic image of a microscopic structure of a composite material composed of a matrix phase and a dispersed phase, and the microscopic image with a predetermined threshold as a reference. An image processing unit that separates a mother phase portion and a dispersed phase portion of a target image, and the mother phase so that the mother phase portion and the dispersed phase portion are divided by uniform elements based on a plurality of finite element methods. The microscopic image after separating the portion and the disperse phase portion is converted into a two-dimensional finite element model, and an analysis unit for analyzing parameters related to the mechanical properties of the composite material using the two-dimensional finite element model And a data processing unit for obtaining a frequency distribution of at least a parameter relating to the mechanical characteristic of the matrix phase part and a parameter relating to the mechanical characteristic of the dispersed phase part from an analysis result of the parameter relating to the mechanical characteristic. It is characterized in.

  This mechanical analysis device for composite materials is a two-dimensional microscopic image in which a matrix phase and a dispersed phase are separated from a microscopic image of a composite material composed of a matrix phase and a dispersed phase on the basis of a predetermined threshold value. An image processing unit that creates a visual image, and an analysis unit that divides a dispersed phase included in the microscopic image into elements based on at least a plurality of finite element methods to form a two-dimensional finite element model. With such a configuration, a two-dimensional finite element model reflecting the morphology information of the composite material can be created. And since the mechanical analysis by the finite element method is performed using such a two-dimensional finite element model, the microscopic structure and the mechanical characteristics of a complex material of an actual complex and various structure The relationship can be quantitatively evaluated. Further, a frequency distribution of principal strain, principal stress, and other parameters related to mechanical characteristics in the matrix phase portion and the dispersed phase portion of the composite material is obtained by a data processing unit included in the composite material mechanical analysis device. Thereby, durability, strength, and other mechanical characteristics of the composite material can be easily evaluated.

  As described above, in the composite material dynamic analysis method according to the present invention, a two-dimensional finite element model reflecting the morphology information of the composite material to be evaluated can be created. Since the finite element method is used to perform the mechanical analysis using the finite element model, the relationship between the microscopic structure and the mechanical characteristics can be quantitatively evaluated even for a complex material having an actual complex and diverse structure.

  Further, according to the composite material dynamic analysis program, the above-described composite material dynamic analysis method can be realized using a computer.

  Also, with this composite material mechanical analysis device, it is possible to create a two-dimensional finite element model reflecting the morphological information of the composite material to be evaluated, and using such a two-dimensional finite element model, a finite element Since the mechanical analysis by the method is executed, the relationship between the microscopic structure and the mechanical characteristics can be quantitatively evaluated even for the actual complex material having various structures. In addition, the data processing unit included in the composite material mechanical analysis device calculates the frequency distribution of the mechanical properties in the matrix phase portion and the disperse phase portion of the composite material, so that the durability and strength of the composite material can be simplified. Can be evaluated.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. In the following description, as a composite material to be handled, a rubber-based composite material in which particles such as carbon black and silica are dispersed as a dispersed phase in a rubber matrix is taken as an example, but the scope of application of the present invention is not limited to this. In addition, the present invention can be applied to analysis of all materials in which the matrix phase includes particles and other dispersed phases, for example, particle-dispersed metal materials.

(Embodiment 1)
The mechanical analysis method for a composite material according to the present invention in Embodiment 1 is characterized by the following points. That is, the microscopic image is divided into a dispersed phase portion and a parent phase portion by performing image processing for separating the dispersed phase portion and the parent phase portion on the microscopic image of the composite material acquired by the magnified image acquisition means. Assign to. Then, a two-dimensional finite element model reflecting morphological information is created by dividing the allocated dispersed phase portion and the parent phase portion by homogeneous elements, and finite element analysis is executed. Then, the analysis result and the experimental result are compared, and the two-dimensional finite element model obtained by correcting the two-dimensional finite element model so that the two coincide with each other. The distribution is obtained, and the characteristics of the composite material are evaluated by the frequency distribution. The parameters relating to the mechanical characteristics include, for example, main strain, main stress, strain energy, and the like. Next, the analysis procedure of the composite material mechanical analysis method according to the present invention in Embodiment 1 will be described.

  FIGS. 1-1 to 1-3 are explanatory diagrams of the composite material dynamic analysis method according to the first embodiment of the present invention. FIG. 2 is a flowchart showing an analysis procedure of the composite material mechanical analysis method according to the first embodiment of the present invention. First, the composite material test piece 1 is enlarged by a scanning probe microscope (SPM) 10 which is an enlarged image acquisition means, and a microscopic image 1i of the composite material is acquired (step S101). The microscopic image 1i is converted into a digital signal by the A / D converter 20, and is taken into the composite material dynamic analysis apparatus 50 according to the present invention. The composite material mechanical analysis device 50 has a function of realizing each step of the composite material dynamic analysis method according to the present invention. Here, as an enlarged image acquisition means, in addition to an electron microscope such as a transmission electron microscope (TEM) or a scanning electron microscope (SEM), an atomic force microscope (a kind of SPM) ( Atomic Force Microscope (AFM) can also be used.

  A two-dimensional finite element model is created based on the acquired microscopic image 1i (step S102). This procedure will be described. FIG. 3 is a flowchart showing a procedure for creating a finite element model according to the present invention in the first embodiment. First, an inappropriate part of the microscopic image 1i (for example, when a microscopic image is acquired by TEM, a missing part of an observation slice in the image) is corrected (step S201). Next, when the microscopic image 1i is a color image, it is converted into a gray image (step S202). As this conversion method, for example, a conversion method for directly converting a color image into a gray image can be used. Alternatively, a conversion method may be used in which a microscopic image 1i that is a color image is subjected to RGB channel decomposition or CMYK channel decomposition to select a channel that best reflects the morphology structure. When the acquired microscopic image 1i is a gray image, the gray image conversion procedure in step S202 is not necessary.

  When the microscopic image 1i is converted into a gray image, the entire microscopic image 1i after conversion into the gray image is appropriately extracted in the binarization described later so that the morphology of the composite material to be analyzed is appropriately extracted. The uneven color and brightness are corrected (step S203). For this correction, constant dispersion emphasis processing or other brightness / contrast adjustment means can be used. Here, the constant dispersion emphasis process is one of local calculation processes for removing unevenness of an image, and is a process for making a signal dispersion and an average value constant in the entire image. Next, in the analysis calculation by the finite element method, the size and resolution of the microscopic image 1i are adjusted so that the created two-dimensional finite element model has an appropriate size (step S204). A corrected microscopic image is obtained by the above procedure.

  This modified microscopic image is binarized with an appropriate threshold value (step S205), and a binarized microscopic image reflecting the morphology is obtained. If the unevenness correction in step S203 is insufficient, adaptive binarization processing is executed in step S205. Here, the adaptive binarization process is a process for determining a threshold value in a region based on the local average intensity of the pixel group. By appropriately selecting a size for executing the local process, image unevenness is determined. By removing (brightness and contrast difference between the left and right images), it is possible to obtain a binarized microscopic image that appropriately reflects only the necessary structural information of the composite material.

  Next, expansion / contraction processing or opening processing / closing processing is executed on the binarized microscopic image to remove unnecessary noise from the binarized microscopic image (step S206). This noise is unnecessary irregularities, isolated points, and the like in the edge portion of the binarized microscopic image. At this time, if the effect of the expansion / contraction process is too strong, even morphological information is lost. For this reason, the expansion / contraction processing is performed by changing the number of pixels adjacent to the reference pixel of the processing such as the expansion processing / contraction processing so that only the noise of the binarized microscopic image is removed. Adjust the effects such as. By the above procedure, a corrected binary microscopic image can be obtained.

  Next, based on the modified binarized microscopic image, a two-dimensional finite element model 1m (FIGS. 1-3) in which white / black of the modified binarized microscopic image is associated with the morphology is created. (Step S207). Here, the white portion of the modified binarized microscopic image corresponds to the matrix phase 2 of the composite material, and the black portion corresponds to the dispersed phase 3 of the composite material. 4A and 4B are explanatory diagrams illustrating a method of dividing the two-dimensional finite element model. When creating the two-dimensional finite element model 1m, as shown in FIG. 4A, the disperse phase 3 is divided by using a plurality of elements 4 based on the finite element method. In particular, when the dispersed phase 3 as shown in FIG. 4-2 is a dispersed particle, it is preferable to divide one particle by at least two elements 4 and more reflect the morphology information of the original composite material. Therefore, it is preferable to divide by 4 or more elements 4.

  Moreover, it is preferable that all the elements 4 based on the finite element method are uniform, that is, all the elements 4 have the same size. This is because handling is facilitated when obtaining a frequency distribution of parameters relating to physical properties of the composite material such as main strain and main stress described later. Here, the element based on the finite element method is preferably an element that can be used by a computer, such as a triangular element or a quadrilateral element in a two-dimensional plane. The microelements divided in this way are identified one by one using two-dimensional coordinates in the analysis process of the finite element method.

The element 4 based on the finite element method in the present embodiment is a square having _two orthogonal sides δ ₁ and δ ₂ . In this embodiment, since δ ₁ = δ ₂ , the element 4 is a square. The size of the element 4 is appropriately changed depending on the composite material to be analyzed, the size of the microscopic image to be acquired, and the like. For example, in the present embodiment, δ ₁ = δ ₂ = 20 nm, and the two-dimensional finite element model 1m is configured by about 250 elements 4 per side of the microscopic image 1i (FIG. 1-2). , FIG. 1-3). The above modeling process can be performed more easily by using the pixels of the modified binarized microscopic image as they are as elements of the finite element model. Alternatively, an element of a finite element model may be created by dividing or combining a plurality of the pixels.

  Next, referring back to FIG. After creating the two-dimensional finite element model based on the microscopic image 1i, the material constant of the composite material is set (step S102), and the composite material to be analyzed in the uniaxial tensile analysis, compression analysis or shear analysis An analysis based on the finite element method of the analysis with the experimental result is performed (step S103). Then, the SS (Stress-Strain) curve obtained by the analysis by the finite element method is compared with the SS curve obtained by the experiment (step S104). S104; Yes), it proceeds to the next step. Here, the term “match” includes not only perfect match but also that the difference between both SS curves is within a predetermined range (the same applies hereinafter). If the two do not match (step S104; No), the created two-dimensional finite element model is corrected (step S105). This correction will be described.

  The two-dimensional finite element model 1m created from the morphology image of the microscopic image 1i is based on a two-dimensional projection image or cross-sectional image, although it depends on the magnified image acquisition means of the composite specimen 1. For this reason, even if this is used as it is for the analysis of the finite element method, the three-dimensional behavior of the composite material in the dynamic experiment may not be sufficiently reproduced. 5-1 is explanatory drawing which shows the structure of the test piece 1 of a composite material. FIG. 5B is an explanatory diagram of a state seen from the direction of arrow A in FIG. As shown in FIG. 5A, in the actual composite material test piece 1, the matrix phase 2 is divided by the dispersed phase 3. However, when this specimen is viewed three-dimensionally, as shown in FIG. 5B, the parent phase 2 divided by the dispersed phase 3 is also directly below or directly above the cross-sectional image (perpendicular to the paper surface in FIG. 5A). linked. The same applies to the two-dimensional finite element model 1m created based on the microscopic image 1i of the test piece 1 of the composite material.

  Therefore, when the analysis of the finite element method is executed using a two-dimensional finite element model, the rigidity of the parent phase 2 is calculated to be lower than the experimental value. Thus, when a two-dimensional finite element model is created, there is a difference between the experimental value and the analytical value. However, when creating the two-dimensional finite element model 1m, the three-dimensional form of the composite material is taken into consideration. By strengthening the connection of the parent phase 2, the analytical value and the experimental value can be matched. In particular, when the dispersed phase 3 is carbon black particles, since the respective particles are finely dispersed in the matrix phase 2, the influence of the division of the matrix phase 2 as described above appears strongly. In such a case, it is preferable to consider three-dimensional parent phase 2 coupling.

  In order to strengthen the connection of the parent phase 2, specifically, it is realized by performing expansion / contraction processing or Watershed division processing on the modified binarized microscopic image that is the basis of the two-dimensional finite element model. it can. However, if the effect of this process is too strong, the loss of the morphological information of the modified binarized microscopic image becomes large. Therefore, it is preferable to perform this process step by step. Further, by combining the above expansion / contraction processing and the like with an operation for further enlarging / reducing the image resolution, it is possible to realize more precise and accurate connection strengthening of the mother phase 2. Thereby, the difference between the experimental value and the analysis value can be further reduced, and the prediction accuracy of the mechanical characteristics of the composite material can be improved. Here, “Watershed” is an image processing algorithm in which the image signal level is regarded as the altitude of the terrain, and the watershed that partitions the basin is used as the boundary of the region. This is used when the connected particle group image in the image is divided into individual particle images.

  Regarding the expansion / contraction process, the effect of the expansion / contraction process is further finely adjusted by adjusting the number of pixels adjacent to the pixel serving as the processing reference. By correcting the two-dimensional finite element model by such a procedure, a corrected two-dimensional finite element model that matches the experimental value can be obtained. As a result, an analysis result reflecting the behavior of the actual composite material can be obtained, so that the relationship between the microscopic structure and the mechanical properties of the composite material with the actual complex and diverse structure can be quantitatively evaluated with higher accuracy. .

  Here, when the disperse phase 3 is silica particles, a certain amount of particles are unevenly distributed in the mother phase 2, so that the influence of the division of the mother phase 2 is relatively difficult to appear. For this reason, even if it does not consider the three-dimensional form of a composite material, an analytical value and an experimental value may correspond. Therefore, it is preferable to determine whether or not to consider the three-dimensional form of the composite material depending on the type and form of the dispersed phase 3.

  Next, using the two-dimensional finite element model 1m or the modified two-dimensional finite element model 1m, analysis of the finite element method is performed when a predetermined strain X is applied to the composite material. FIG. 6A is an explanatory diagram of a two-dimensional finite element model or a corrected two-dimensional finite element model. FIG. 6B is an explanatory diagram illustrating a state in which a predetermined tensile strain is applied to the two-dimensional finite element model or the corrected two-dimensional finite element model. In this example, by applying a tensile force F to the two-dimensional finite element model 1m shown in FIG. 6-1 (FIG. 6-2), a tensile strain X = δl / l is applied to the two-dimensional finite element model, and the finite element Perform law-based analysis. Based on the analysis results, the main elements of the element group of the two-dimensional finite element model belonging to the matrix interface part, the matrix non-interface part (matrix part), the dispersed phase interface part, and the dispersed phase non-interface part (dispersed phase part) A frequency distribution of strain, principal stress and strain energy is created (step S106), and based on this, durability, strength and other mechanical characteristics of the composite material are evaluated.

  In order to determine the part to which each element of the two-dimensional finite element model 1m belongs, in addition to the criterion of whether or not the element belongs to either the mother phase or the dispersed phase, the element includes the mother phase and the dispersed phase. Judgment criteria of whether or not it belongs to the vicinity of the interface is necessary. FIG. 7A to FIG. 7D are explanatory diagrams illustrating an example of determining the phase to which each element belongs. Whether a given element P is an interface part or a non-interface part is determined by, for example, selecting at least one element group in the vicinity of the element of interest P to be determined (hereinafter abbreviated as a neighboring element group). If there is a pixel having a different value, it is determined that the target element P belongs to the interface.

  For example, in FIG. 7A, the target element P is the parent phase 2, and all neighboring elements are also the parent phase 2. In this case, the target element P is determined to belong to the parent phase, that is, the non-interface portion. On the other hand, in FIG. 7B, only one element is included in the disperse phase 3 in the neighborhood element group of the target element P. Therefore, in this case, it is determined that the target element P belongs to the interface portion.

  Here, the criteria for determining pixels belonging to the vicinity of the interface can be adjusted by the number of pixels having different phases in the neighboring element group and the setting of the neighboring element group. The setting of the neighboring element group is, for example, a setting for whether the neighboring element group is connected to the target element P by four linkages or eight linkages. Here, as shown in FIG. 7C, the four elements among the elements adjacent to the target element P are the four connected elements. And as shown to FIGS. 7-4, what connected 8 elements among the elements adjacent to the attention element P is 8 connection.

  In addition, obtain the logical sum of the mother phase interface and the non-interface portion of the mother phase, and the logical sum of the interface portion of the dispersed phase and the non-interface portion of the dispersed phase, and obtain the frequency distribution in the entire mother phase and the entire dispersed phase. You can also. FIG. 8 is an explanatory diagram showing a main strain frequency distribution obtained by the present invention according to the first embodiment. In the present embodiment, since the distribution range of the strain ε is wide, the logarithmic display is used.

  When the above analysis is performed on a plurality of test pieces, comparison between the plurality of test pieces can be performed. The test piece may be a test piece made of a different kind of composite material or a test piece made of the same kind of composite material. In the former, the mechanical characteristics between different materials can be evaluated, and in the latter, the mechanical characteristics due to the difference in the microscopic structure of the materials can be evaluated.

  When evaluating the mechanical properties between multiple specimens, for example, a composite specimen containing many elements with large principal strain, principal stress, and strain energy values is considered to have low strength as a whole. be able to. Therefore, in the evaluation between test pieces, evaluation is performed with the number of elements having large values of principal strain, principal stress, and strain energy from the frequency distribution. In order to determine the number of elements having a large value, it is determined not by the entire frequency distribution but by the tail having a large value in FIG. 8 above, but in order to make the determination easier, the integrated distribution obtained from Equation 1 is used. Q (x) is used to evaluate the mechanical properties of the composite material (step S107). Here, ρ is a frequency distribution function, which is a function representing the curve shown in FIG. Further, x is a parameter value relating to principal strain, principal stress or other mechanical characteristics. FIG. 9 is an explanatory diagram showing the cumulative distribution of main stress obtained from Equation 1.

  From FIG. 9, it can be seen that the composite specimen including many elements having a large principal strain value is No. No. 1 is a composite specimen with a small number of elements having a large principal strain value. 3. That is, no. No. 1 test piece has the lowest durability. It can be judged that the durability of the test piece 3 is the highest. Thus, according to the integrated distribution of each element with respect to the main strain, main stress, and strain energy obtained from the frequency distribution, the mechanical characteristics of the composite material can be easily evaluated.

  Next, if there is any other necessary analysis (step S108; Yes), an analysis not executed in the uniaxial tensile analysis, compression analysis, or shear analysis is executed (step S109), and the main strain, main stress, etc. The mechanical properties of the composite material are evaluated by the frequency distribution (step S110) or the integrated distribution (step S111), and all procedures are completed. If there is no other necessary analysis (step S108; No), all procedures are completed.

  Next, a mechanical analysis device for a composite material according to an embodiment of the present invention will be described. 10-1 is explanatory drawing which shows the mechanical analysis apparatus of the composite material which concerns on Embodiment 1 of this invention. FIG. 10B is an explanatory diagram of the configuration of the processing unit. The structural body dynamic analysis device 50 includes a processing unit 52 and a storage unit 54. As illustrated in FIG. 10B, the processing unit 52 includes an image processing unit 52ip that performs image processing such as binarization on a microscopic image, an analysis unit 52a that performs analysis by a finite element method, and a frequency. A data processing unit 52p for obtaining a distribution and an integrated distribution.

  Further, an input / output device 51 is connected to the mechanical structure analysis device 50 of this structure, and an input unit 53 provided therein analyzes the material constants of the composite material and the finite element method. A boundary condition and the like for execution are input to the processing unit 52. Here, an input device such as a keyboard and a mouse can be used for the input unit 53. The storage unit 54 stores a computer program (also called a program) for causing a computer to execute the composite material dynamic analysis method according to the present invention. Here, the storage unit 54 is a hard disk device, a magneto-optical disk device, a non-volatile memory such as a flash memory, a readable storage medium such as a CD-ROM, or a RAM (Random Access Memory). Such a volatile memory, or a combination thereof.

  The computer program may be capable of realizing the composite material dynamic analysis method according to the present invention in combination with a computer program already recorded in the computer system. Further, the computer program for realizing the functions of the image processing unit 52ip, the analysis unit 52a, and the data processing unit 52p constituting the processing unit 52 is recorded on a computer-readable recording medium, and recorded on the recording medium. The composite material dynamic analysis method according to the present invention may be executed by causing a computer system to read and execute the computer program. The “computer system” here includes an OS and hardware such as peripheral devices.

  The processing unit 52 includes a memory and a CPU. In executing the composite material dynamic analysis method according to the present invention, the processing unit 52 reads the computer program into a memory incorporated in the processing unit 52 and performs calculation. At that time, the processing unit 52 appropriately stores the numerical value in the middle of the calculation in the storage unit 54, and advances the calculation by taking out the stored numerical value. Note that the functions of the image processing unit 52ip, the analysis unit 52a, and the data processing unit 52p constituting the processing unit 52 may be realized by dedicated hardware instead of the computer program.

(Modification)
FIG. 11A and FIG. 11B are plan views showing microscopic images of a composite material having a boundary phase between the matrix phase and the dispersed phase. Thus, the present invention can also be applied when the boundary phase 5 exists between the parent phase 2 and the dispersed phase 3. In this case, a two-dimensional finite element model composed of three phases including the boundary phase 5 is created instead of the two-dimensional finite element model composed of the two phases of the parent phase 2 and the dispersed phase 3 described above. . In this case, a ternary microscopic image can be obtained by setting a plurality of thresholds when processing the corrected microscopic image. Further, the boundary phase 5 can also be added by performing expansion / contraction processing on the binary phase microscopic image once created.

  According to the present invention relating to this modification, the analysis result can be obtained in a state closer to the structure of the actual composite material, so that the microscopic structure and mechanical characteristics of the composite material of the actual complex and various structures can be obtained. Can be quantitatively evaluated with higher accuracy. The composite material that can be handled in the present invention is not limited to two-phase and three-phase, and can be applied to a composite material having four or more phases.

  As mentioned above, according to this invention which concerns on Embodiment 1 and its modification, the two-dimensional finite element model reflecting the morphology information of the composite material to be evaluated can be created. And since the mechanical analysis by the finite element method is performed using such a two-dimensional finite element model, the microscopic structure and the mechanical characteristics of a complex material of an actual complex and various structure The relationship can be quantitatively evaluated. In addition, since the two-dimensional finite element model is created with uniform elements, the frequency distribution of parameters related to the principal strain, principal stress, and other mechanical characteristics of the composite material can be easily obtained. Further, according to the frequency distribution of parameters relating to the mechanical properties of the composite material and the cumulative distribution obtained from the frequency distribution, the durability, strength, and the like of the composite material can be easily evaluated. Note that each configuration of the present invention disclosed in Embodiment 1 can be applied as appropriate in the following embodiments.

(Embodiment 2)
The mechanical analysis method of the composite material according to the second embodiment has substantially the same configuration as the mechanical analysis method of the composite material according to the first embodiment, but handles the case where the material constant of the composite material is unknown. Is different. Since other configurations are the same as those of the first embodiment, the description thereof is omitted and the same components are denoted by the same reference numerals. FIG. 12 is a flowchart showing an analysis procedure of the composite material mechanical analysis method according to the second embodiment of the present invention.

  First, a two-dimensional finite element model is created from the obtained microscopic image of the composite material test piece 1 (steps S301 and S302). Since these procedures are the same as the procedures described in the first embodiment (steps S101 and S102), description thereof is omitted. Next, the created two-dimensional finite element model is corrected to a two-dimensional finite element model considering a three-dimensional form (step S303), and experimental results exist among uniaxial tensile analysis, compression analysis, and shear analysis. For the object, analysis by the finite element method is selected using the modified two-dimensional element model (step S304).

  Next, the material constant is set as it is for a material that is clear, and the expected material constant value is temporarily set for a material that is not clear (step S305). Then, using the corrected two-dimensional element model, a finite element analysis of an analysis with an experimental result of the composite material to be analyzed is executed in a uniaxial tensile analysis, a compression analysis, or a shear analysis (step S306). . Then, the SS (Stress-Strain) curve obtained by the analysis by the finite element method is compared with the SS curve obtained by the experiment (step S307). S307; Yes), the process proceeds to the next procedure.

  If the two do not match (step S307; No), the material constant is reset, and steps S305 and S306 are repeated until the two match. Thereby, even if the material constant is unknown, the mechanical properties of the composite material can be evaluated. In addition, since an analysis result reflecting the behavior of the actual composite material can be obtained, the relationship between the microscopic structure and the mechanical properties in the composite material having an actual complex and various structure can be quantitatively evaluated with higher accuracy. If the SS (Stress-Strain) curve obtained by the analysis by the finite element method and the SS curve obtained by the experiment coincide with each other, the frequency distribution of the created main strain and the like (step S308) From the integrated distribution (step S309), the mechanical properties of the composite material are evaluated. Hereinafter, steps S309 to S313 are the same as steps S108 to S111 of the first embodiment, and thus description thereof is omitted.

  As described above, according to the present invention according to the second embodiment, even when a composite material whose material constant is unknown is handled, an analysis result reflecting the behavior of the actual composite material can be obtained. The relationship between microscopic structure and mechanical properties can be quantitatively evaluated.

  As described above, the composite material mechanical analysis method and program, and the composite material mechanical analysis apparatus according to the present invention are useful for analyzing the mechanical properties of the composite material. It is suitable for quantitative evaluation of the relationship with mechanical properties.

FIG. 2 is an explanatory diagram of a composite material dynamic analysis method according to the first embodiment of the present invention. FIG. 2 is an explanatory diagram of a composite material dynamic analysis method according to the first embodiment of the present invention. FIG. 2 is an explanatory diagram of a composite material dynamic analysis method according to the first embodiment of the present invention. 3 is a flowchart showing an analysis procedure of a mechanical analysis method for a composite material according to the present invention in Embodiment 1. 3 is a flowchart showing a procedure for creating a finite element model according to the present invention in Embodiment 1; It is explanatory drawing which shows the division | segmentation method of a two-dimensional finite element model. It is explanatory drawing which shows the division | segmentation method of a two-dimensional finite element model. It is explanatory drawing which shows the structure of the test piece 1 of a composite material. It is explanatory drawing which shows the state seen from the arrow A direction of FIGS. It is explanatory drawing which shows a two-dimensional finite element model or a two-dimensional finite element model after correction. It is explanatory drawing which shows the state which gave the predetermined | prescribed tensile strain to the two-dimensional finite element model or the two-dimensional finite element model after correction. It is explanatory drawing which shows the example which determines the phase to which each element belongs. It is explanatory drawing which shows the example which determines the phase to which each element belongs. It is explanatory drawing which shows the example which determines the phase to which each element belongs. It is explanatory drawing which shows the example which determines the phase to which each element belongs. It is explanatory drawing which shows the frequency distribution of the main distortion obtained by this invention which concerns on Embodiment 1. FIG. FIG. 3 is an explanatory diagram showing a cumulative distribution of main stress obtained from Equation 1. It is explanatory drawing which shows the mechanical analysis apparatus of the composite material which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the structure of a process part. It is a top view which shows the microscopic image of the composite material which has a boundary phase between a mother phase and a dispersed phase. It is a top view which shows the microscopic image of the composite material which has a boundary phase between a mother phase and a dispersed phase. 5 is a flowchart showing an analysis procedure of a composite material mechanical analysis method according to the present invention in Embodiment 2. It is a conceptual diagram which shows the microscopic image of a composite material. It is a conceptual diagram which shows the preparation method of the finite element model with respect to a microscopic image currently disclosed by patent documents 1-3. It is a conceptual diagram which shows the microscopic image of an actual more complicated and various composite material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Test piece 1i Microscopic image 1m Two-dimensional finite element model 2,102 Mother phase 3 Dispersed phase 4 Element 5 Boundary phase 20 A / D converter 50 Mechanical analysis apparatus 52 Processing part 52a Analysis part 52ip Image processing part 52p Data Processing part

Claims (14)

An image acquisition step for obtaining a microscopic image of the microscopic structure of the composite material composed of a matrix phase and a dispersed phase;
A separation step of separating a mother phase portion and a dispersed phase portion of the microscopic image with reference to a predetermined threshold;
A finite element model creating step for modeling the microscopic image after the separation step into a two-dimensional finite element model so that the parent phase portion and the dispersed phase portion are divided by elements based on a plurality of finite element methods; ,
Performing a mechanical analysis of the composite material using the two-dimensional finite element model to obtain parameters relating to the mechanical properties of the composite material;
A method for mechanically analyzing a composite material, comprising:   2. The method for mechanically analyzing a composite material according to claim 1, wherein the microscopic image is modeled as a two-dimensional finite element by the uniform element.   After the analysis step, the experimental result of the composite material for the same mechanical property as the mechanical property evaluated in the analysis step is compared with the analysis result using the two-dimensional finite element model, and based on the comparison result, The mechanical analysis method for a composite material according to claim 1, wherein the two-dimensional finite element model is corrected.   When the experimental result for the composite material is compared with the analysis result using the two-dimensional finite element model, and the difference between the two is larger than a predetermined range, the three-dimensional form of the microscopic structure of the composite material The composite material dynamic analysis method according to claim 3, wherein the two-dimensional finite element model is corrected in consideration of the above.   The experimental result for the composite material is compared with the analysis result using the two-dimensional finite element model, and when the difference between the two is larger than a predetermined range, the material constant of the composite material is changed and the 2 The mechanical analysis method for a composite material according to claim 3, wherein the dimensional finite element model is corrected.   From the analysis result using the two-dimensional finite element model or the modified two-dimensional finite element model, frequency distributions of at least parameters relating to the mechanical characteristics of the parent phase part and parameters relating to the mechanical characteristics of the dispersed phase part are obtained. The mechanical analysis method of a composite material according to any one of claims 1 to 5.   The composite material mechanical analysis method according to claim 6, wherein an integrated distribution of parameters relating to mechanical properties of the composite material is obtained from the function of the frequency distribution.   The mechanical property of the composite material according to any one of claims 1 to 7, wherein in the separation step, a boundary region existing between the matrix phase and the dispersed phase of the composite material is also separated. Analysis method. An image acquisition procedure for obtaining a microscopic image of a microscopic structure of a composite material composed of a matrix phase and a dispersed phase;
A separation procedure for separating a mother phase part and a dispersed phase part of the microscopic image with reference to a predetermined threshold;
A finite element model creation procedure for modeling the microscopic image after the separation step into a two-dimensional finite element model so that the parent phase portion and the dispersed phase portion are divided by elements based on a plurality of finite element methods; ,
An analysis procedure for determining a parameter relating to mechanical properties of the composite material by performing a mechanical analysis of the composite material using the two-dimensional finite element model;
A mechanical analysis program for composite materials, characterized in that a computer is executed.   10. The composite material dynamic analysis program according to claim 9, wherein the microscopic image is modeled in a two-dimensional finite element by the uniform element.   After the analysis procedure, the experimental result of the composite material for the same mechanical property as the mechanical property evaluated in the analysis procedure is compared with the analysis result using the two-dimensional finite element model, and based on the comparison result, 11. The composite material dynamic analysis program according to claim 9 or 10, wherein the two-dimensional finite element model is corrected.   From the analysis result using the two-dimensional finite element model or the modified two-dimensional finite element model, at least a parameter relating to the mechanical characteristics of the parent phase part and a frequency distribution of parameters relating to the mechanical characteristics of the dispersed phase part are obtained. The mechanical analysis program for a composite material according to any one of claims 9 to 11.   13. The composite material dynamic analysis program according to claim 12, wherein an integrated distribution of parameters relating to mechanical properties of the composite material is obtained from the function of the frequency distribution. An image processing unit that separates a matrix phase portion and a dispersion phase portion of the microscopic image with respect to a microscopic image of a microscopic structure of a composite material composed of a matrix phase and a dispersion phase with a predetermined threshold as a reference When,
The microscopic image after separating the mother phase portion and the dispersed phase portion so that the mother phase portion and the dispersed phase portion are divided by uniform elements based on a plurality of finite element methods is represented by 2 An analysis unit that analyzes a parameter related to mechanical properties of the composite material using the two-dimensional finite element model,
A data processing unit that obtains a frequency distribution of at least a parameter related to the mechanical characteristics of the parent phase part and a parameter related to the mechanical characteristics of the dispersed phase part from the analysis result of the parameters related to the mechanical characteristics;
An apparatus for mechanical analysis of a composite material comprising:

Images