JP2020042431A - Analyzing method of composite material and computer program for analyzing composite material - Google Patents

Abstract

To provide an analyzing method of a composite material and a computer program for analyzing the composite material that make it possible to specify a broken portion of inter-particle bonds.SOLUTION: In the method of analyzing a composite material, a computer: in a first step, creates a model for analyzing a specific substance including a specific substance model in which a specific substance is modeled; in a second step, sets a threshold for an inter-particle distance of at least a pair of particles coupled by inter-particle bonds and belonging to a specific substance model to be analyzed; in a third step, breaks the inter-particle bonds when the inter-particle distance is equal to or greater than the threshold; and in a fourth step, performs a numerical analysis of the analysis model by changing the binding energy or the binding force of the broken inter-particle bonds according to a lapse of time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for analyzing a composite material and a computer program for analyzing a composite material, for example, a method for analyzing a composite material containing two or more substances and a computer program for analyzing a composite material.

  Conventionally, a simulation method of a composite material using molecular dynamics has been proposed (for example, see Patent Document 1). In the method for simulating a composite material described in Patent Literature 1, a polymer model and a filler model are created in a model creation region, and then the polymer model is joined to a joining position on the filler model surface. Accordingly, in the method for analyzing a composite material described in Patent Document 1, it is possible to analyze the influence of the bonding state of the polymer particles on the filler surface on the material properties of the composite material.

JP-A-2005-064242

  Incidentally, in order to accelerate the development of a rubber material that improves the wear resistance of a tire, it is helpful to clarify the mechanism of nanostructure destruction accompanying deformation of the rubber material. By analyzing the destruction of the nanostructure of the rubber material before and after the deformation, it is possible to accelerate the material development for improving the breaking strength of the filler-filled rubber used in the actual tire.

  However, in the conventional numerical analysis by molecular dynamics, in order to analyze the destruction of the nanostructure due to the deformation of the rubber material, it is necessary to break and eliminate the inter-particle bonds of the polymer particles in the rubber material. For this reason, even if the polymer model after the fracture is analyzed, since the interparticle bonds have already disappeared, the fracture location cannot be specified, and it is difficult to analyze the mechanism of the destruction of the rubber material nanostructure. Was.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a method for analyzing a composite material and a computer program for analyzing the composite material, which enable the identification of a broken portion of interparticle bonding. .

  The method for analyzing a composite material according to the present invention is a method for analyzing a composite material by a molecular dynamics method using a computer, wherein the computer is a model for analyzing a specific substance including a specific substance model obtained by modeling a specific substance. A second step of setting a threshold value for the inter-particle distance of at least a pair of particles belonging to a specific substance model to be analyzed and coupled by inter-particle bonding; and In the above case, the third step of breaking the inter-particle bond, and changing the binding energy or the binding force of the broken inter-particle bond according to the elapsed time to perform a numerical analysis of the analysis model. And a fourth step to be executed.

  According to the method for analyzing a composite material according to the present invention, since the bonding energy or the bonding force of the bonding between the particles when the bonding between the particles is subjected to the breaking treatment changes according to the elapsed time, the molecules of the specific substance that has been subjected to the breaking treatment. The stretching speed of the chain can be changed. Thereby, the reproducibility of the mechanical response accompanying the breaking of the interparticle bond is improved. Since the breaking process can be performed in a simulated manner, even in a region where the interparticle distance is equal to or larger than the threshold value, the analysis model can be numerically analyzed without the interparticle coupling being erased by the fracture. Thus, the method of analyzing a composite material can prevent physical disappearance of interparticle bonding due to fracture, and can reproduce pseudo fracture of interparticle coupling.

  In the method for analyzing a composite material according to the present invention, in the fourth step, it is preferable that only the binding energy or the binding force at a distance equal to or greater than the breaking threshold is changed with time. By this method, it is possible to alleviate the sudden shrinkage of the binding chain after cleavage. As a result, the reproducibility of the mechanical response accompanying the fracture is further improved.

  In the method for analyzing a composite material according to the present invention, it is preferable that the computer includes a step of crosslinking the specific substance between the first step and the second step. With this method, the method for analyzing a composite material enables numerical analysis of an analysis model in a state where a specific substance has been cross-linked in advance through a cross-linking reaction, enabling analysis of the effect of cross-linking of a specific substance on interparticle bond breaking. Becomes

  In the composite material analysis method of the present invention, it is preferable that the computer sets a threshold range having a numerical range as the threshold in the second step. According to this method, the method for analyzing a composite material not only reduces the binding energy and / or binding force only at a specific threshold value, but also reduces the binding energy and / or binding force at any value within the threshold range. Therefore, it is possible to adjust the probability of occurrence of breakage of the bond between particles. As a result, the method of analyzing a composite material can accurately reproduce the breaking of the bond between particles in the actual composite material.

  It is preferable that the breaking process is a pseudo breaking process using a function for calculating a break connection. According to the method described above, the method of analyzing a composite material can reproduce a pseudo cut of a pair of particles to be analyzed in a numerical analysis of an analysis model, so that, for example, a polymer molecule in an actual composite material such as a filler-filled rubber. Can be accurately reproduced.

  In the method for analyzing a composite material according to the present invention, the fracture bond calculation function reduces at least one of the bond energy and the bond force of the interparticle bond from the lower limit to the upper limit of the threshold range. Is preferred. According to this method, the analysis method of the composite material is such that at least one of the binding energy and the binding force of the pair of polymer particles gradually decreases within the threshold range as the distance between the particles increases, so that the fracture of the bond between the particles occurs. The probability can be adjusted with high accuracy. As a result, it is possible to reproduce the breaking of the interparticle bond in the actual composite material with higher accuracy.

  In the method for analyzing a composite material according to the present invention, in the fourth step, when the distance between the particles is less than the threshold, the computer performs the numerical analysis by using an operation function different from the fracture bonding operation function. And when the interparticle distance is equal to or greater than the threshold value, it is preferable to execute the numerical analysis using the function for calculating the fracture coupling. According to this method, in the method for analyzing the composite material, in a region where the distance between the particles is equal to or larger than the threshold, at least one of the bond energy and the bond force of the bond between the particles is reduced by using the function for calculating the fracture bond. It is possible to continue the numerical analysis of the analysis model without breaking and eliminating the bond. This can prevent the physical disappearance of the inter-particle bond due to the breakage, so that it is possible to reproduce a pseudo cut without physically eliminating the inter-particle bond. Therefore, it is possible to realize a method of analyzing a composite material, which can specify a broken portion of a bond between particles broken during a numerical analysis.

  In the method for analyzing a composite material according to the present invention, in the fourth step, when the time average value of the distance between the particles is equal to or more than a predetermined value, the computer uses the function for calculating the fracture bond to calculate the numerical value. Preferably, an analysis is performed. According to this method, the method of analyzing a composite material uses a function for a rupture bond calculation that lowers the bond energy and bond strength of the bond between particles in a pair of particles in which the bond between particles has temporarily exceeded a threshold due to Brownian motion or the like. Since the calculation involved can be excluded, it is possible to accurately reproduce the breaking of the interparticle bond in the actual composite material.

  In the method for analyzing a composite material of the present invention, it is preferable that the function for calculating the fracture bond substantially eliminates at least one of the bond energy and the bond force of the interparticle bond. According to this method, the method of analyzing a composite material can accurately reproduce a pseudo cut of a pair of particles to be analyzed at the time of numerical analysis of an analysis model. It is possible to accurately reproduce a break of a polymer molecule or the like.

  In the method for analyzing a composite material according to the present invention, in the fourth step, the computer specifies and evaluates the coordinates of the interparticle bond at the time when the interparticle distance becomes equal to or larger than the threshold as fracture coordinates. Is preferred. According to this method, the method for analyzing a composite material can evaluate a position where the interparticle bond is easily broken as a breaking coordinate. For example, the relationship between the distance from the first substance or the second substance and the breaking probability is determined. It becomes possible to evaluate.

  In the method for analyzing a composite material according to the present invention, it is preferable that in the fourth step, the computer specifies a fracture point by setting a representative point for the interparticle bond. According to this method, the analysis method of the composite material can evaluate the coordinates of the representative point of the interparticle bond having the increased length as the breaking position, and thus can easily evaluate the breaking position.

  In the method for analyzing a composite material according to the present invention, it is preferable that the computer visualizes the representative points in the fourth step. According to this method, the analysis method of the composite material visualizes the representative points without visualizing the entire length of the inter-particle bonds, so that it is easy to confirm the broken inter-particle bonds.

  In the method for analyzing a composite material according to the present invention, it is preferable that the computer visualizes the fracture coordinates in the fourth step. According to this method, in the method for analyzing a composite material, locations that are easily broken can be visually evaluated, so that the locations that are easily broken can be easily evaluated.

  In the method for analyzing a composite material according to the present invention, it is preferable that the computer visualizes the interparticle coupling in which the interparticle distance is equal to or larger than the threshold in the fourth step. According to this method, the method of analyzing a composite material allows visual confirmation of interparticle bonding between a pair of pseudo-broken particles. Become.

  In the method for analyzing a composite material according to the present invention, in the fourth step, the computer preferably executes the visualization at a plurality of analysis times during the numerical analysis. According to this method, the analysis method of the composite material can confirm the progress of the fracture of the interparticle bond at each of a plurality of analysis times.

  In the method for analyzing a composite material according to the present invention, in the fourth step, the computer executes the numerical analysis on each of a plurality of first material models or second material models included in the analysis model, and It is preferable to collectively visualize and evaluate the results of a plurality of numerical analysis obtained. According to this method, the analysis method of the composite material can collectively visualize the analysis results of the numerical analysis of the plurality of first material models or the second material models in the analysis model, so that the analysis results can be obtained quickly. The analysis result can be easily understood.

  In the method for analyzing a composite material according to the present invention, the computer may include, in the fourth step, a representative of a specific first material model or a second material model in which a plurality of numerical analysis results are designated in the analysis model. It is preferable to visualize and evaluate by collecting them in a model. According to this method, the analysis method of the composite material can collectively visualize the analysis results of the numerical analysis using the plurality of first substance models or the second substance models in the analysis model in a representative model, so that the analysis results can be obtained quickly. And the analysis results are easily understood.

  In the method for analyzing a composite material according to the present invention, the specific substance preferably includes a polymer and a filler. According to this method, the analysis method of the composite material can accurately reproduce the analysis result of an actual composite material such as a filler-filled rubber.

  A computer program for analyzing a composite material according to the present invention causes a computer to execute the above-described method for analyzing a composite material.

  According to the computer program for analyzing the composite material of the present invention, the bond energy or bond force of the bond between the particles when the bond between the particles is subjected to the breaking treatment changes according to the elapsed time, so that the specific material subjected to the breaking treatment is broken. The stretching speed of the molecular chain can be changed. Thereby, the reproducibility of the mechanical response accompanying the breaking of the interparticle bond is improved. Since the breaking process can be performed in a simulated manner, even in a region where the interparticle distance is equal to or larger than the threshold value, the analysis model can be numerically analyzed without the interparticle coupling being erased by the fracture. Thus, the method of analyzing a composite material can prevent physical disappearance of interparticle bonding due to fracture, and can reproduce pseudo fracture of interparticle coupling.

  ADVANTAGE OF THE INVENTION According to this invention, the analysis method of the composite material and the computer program for the analysis of a composite material which enable specification of the fracture | rupture part of the bond between particles can be implement | achieved.

FIG. 1 is a flowchart schematically illustrating an example of a method for analyzing a composite material according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing an example of the composite material analysis model 1 according to the present embodiment. FIG. 3 is a diagram for explaining the relationship between the length of the binding chain and the binding force. FIG. 4 is a schematic diagram for explaining a state of a binding chain. FIG. 5 is a diagram for explaining the relationship between the length of the binding chain and the binding force when the force acting on the binding chain on which the cutting process has been performed is made time-dependent. FIG. 6 is a schematic diagram for explaining a state of a binding chain. FIG. 7 is a diagram illustrating an example of the relationship between the elapsed time and the length of the binding chain. FIG. 8A is an explanatory diagram of a breaking position of a bond between particles in a model creation region. FIG. 8B is an explanatory diagram of a breaking position of a bond between particles in a model creation region. FIG. 8C is an explanatory diagram of a breaking position of a bond between particles in a model creation region. FIG. 9 is a diagram illustrating an example of the relationship between the distance from the filler model surface and the coordinate distribution of the fracture coordinates. FIG. 10A is an explanatory diagram of an example of visualization at three analysis times of the first analysis time T1 to the third analysis time T3. FIG. 10B is an explanatory diagram of an example of visualization at three analysis times of the first analysis time T1 to the third analysis time T3. FIG. 10C is an explanatory diagram of an example of visualization at three analysis times of the first analysis time T1 to the third analysis time T3. FIG. 11A is an explanatory diagram of an example in which two analysis times of a first analysis time T1 and a second analysis time T2 are aggregated and visualized. FIG. 11B is an explanatory diagram of an example in which two analysis times of a first analysis time T1 and a second analysis time T2 are aggregated and visualized. FIG. 12 is a flowchart illustrating an outline of an example of the method for analyzing a composite material according to the embodiment of the present invention. FIG. 13 is a functional block diagram of a composite material analysis method and an analysis device that executes the composite material analysis method according to the present embodiment. FIG. 14 is a flowchart schematically illustrating an example of a method for analyzing a composite material according to an example of the present invention. FIG. 15 is a diagram illustrating a stress-strain curve according to the example of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications. Although the following describes an example in which the composite material to be analyzed includes a polymer and a filler, the present invention is also applicable to a composite material containing two or more types of substances. The present invention is also applicable to composite materials containing substances other than fillers and polymers.

  FIG. 1 is a flowchart illustrating an outline of a method for analyzing a composite material according to the present embodiment. As shown in FIG. 1, the method for analyzing a composite material according to the present embodiment includes a computer-based molecule including a first step ST11, a second step ST12, a third step ST13, and a fourth step ST14. This is a method for analyzing a composite material by a dynamics method.

  In the first step ST11, the computer generates a composite material including a polymer model (first substance model) modeling a polymer (first substance) and a filler model (second substance model) modeling a filler (second substance). Create an analysis model for.

  In the second step ST12, the computer sets a threshold value for the inter-particle distance of at least one pair of particles belonging to the first material model or the second material model to be analyzed and coupled by inter-particle bonding.

  In the third step ST13, when the distance between the particles is equal to or larger than the threshold value, the computer breaks the interparticle bond.

  Then, in the fourth step ST14, the computer executes a numerical analysis of the analysis model by changing the binding energy or the binding force of the fractured inter-particle bond according to the elapsed time.

  FIG. 2 is a conceptual diagram showing an example of the composite material analysis model 1 according to the present embodiment. As shown in FIG. 2, the analysis model 1 is modeled in, for example, a model creation area A which is a substantially cubic virtual space with one side length L. The model creation area A is a three-dimensional space extending in the X-axis, Y-axis, and Z-axis directions orthogonal to each other. The analysis model 1 includes four filler models 11A, 11B, 11C, and 11D in which a plurality of filler particles 11a are modeled, and four polymer models 21 in which a plurality of polymer particles 21a and bonding chains 21b are modeled. Including. In the example illustrated in FIG. 2, an example in which the analysis model 1 is modeled on four filler models 11A, 11B, 11C, and 11D will be described. However, the number of filler models to be modeled is not limited. The analysis model 1 may include less than four filler models 11, or may include more than four filler models 11. Although only four polymer models 21 are shown in FIG. 2, in the analysis model 1, a plurality of polymer models 21 exist in the entire model creation region A. Furthermore, in the example shown in FIG. 2, the model creation area A is an example of a virtual space having a substantially rectangular parallelepiped shape, but may have an arbitrary shape such as a spherical shape, an elliptical shape, a rectangular parallelepiped shape, or a polyhedral shape.

  The filler model 11 is modeled in a state where a plurality of filler particles 11a are respectively aggregated into a substantially spherical body. In addition, the filler models 11 are arranged in a state where they are separated from each other by a predetermined distance. Note that the outer edges of the filler model 11 may be connected to each other by covalent bonds in a state where they are aggregated with each other.

  Examples of the filler include carbon black, silica, and alumina. The filler particles 11a are modeled by assembling a plurality of filler atoms. In addition, the filler particles 11a form a filler particle group by aggregating the plurality of filler particles 11a. The relative position of the filler particles 11a is specified by a bonding chain (not shown) between the plurality of filler particles 11a. The bonding chain (not shown) has a function as a spring in which an equilibrium length, which is a bonding distance between the filler particles 11a, and a spring constant are defined, and constrains between the filler particles 11a. The bonding chain is a bond in which the relative position of the filler particles 11a and the potential at which a force is generated by twisting or bending are defined. The filler model 11 is numerical data including the mass, volume, diameter, initial coordinates, and the like of the filler particles 11a for handling the filler by molecular dynamics. The numerical data of the filler model 11 is input to a computer.

  Examples of the polymer include rubber, resin, and elastomer. The polymer particles 21a are modeled by assembling a plurality of polymer atoms. Further, the polymer particles 21a constitute a polymer particle group by a plurality of polymer particles 21a being aggregated. A modifying agent that increases the affinity for the filler is added to the polymer as necessary. Examples of the modifier include a hydroxyl group, a carbonyl group, and a functional group of an atomic group. The polymer model 21 is modeled by filling a plurality of polymer atoms and polymer particles 21a, which are aggregates of a plurality of polymer atoms, into the model creation region A at a predetermined density. The relative positions of the polymer particles 21a are specified by the bonding chains 21b between the plurality of polymer particles 21a. The bonding chain 21b has a function as a spring in which an equilibrium length, which is a bonding distance between the polymer particles 21a, and a spring constant are defined, and constrains between the polymer particles 21a. The bonding chain 21b is a bond in which the relative position of the polymer particles 21a and the potential at which a force is generated by twisting, bending, and the like are defined. Further, the bonding chain 21b is also connected as a cross-link (not shown) between the polymer models 21 in which a plurality of polymer particles 21a are connected in series. The polymer model 21 is numerical data (including the mass, volume, diameter, initial coordinates, etc., of the polymer particles 21a) for handling a polymer by molecular dynamics. The numerical data of the polymer model 21 is input to a computer.

  In the analysis model 1, various physical quantities are obtained by numerical analysis using a molecular dynamics method. Examples of the numerical analysis include a deformation analysis such as an extension analysis and a shear analysis and a motion analysis such as a relaxation analysis. The physical quantity acquired in the motion analysis may use a value such as a displacement obtained as a result of the motion analysis, or may be a distortion obtained by executing a predetermined calculation process. Among them, as the motion analysis, a deformation analysis is preferable from the viewpoint that the mechanical properties of the compound of the composite material can be analyzed.

  Next, the method for analyzing a composite material according to the present embodiment will be described in detail. In the first step ST11, a composite material including a filler model 11 in which a plurality of filler particles 11a are aggregated and modeled and a polymer model 21 in which a plurality of polymer particles 21a are modeled by being connected via a bonding chain 21b. An analysis model 1 (see FIG. 2) is created.

  In the first step ST11, an interaction is set between the created filler model 11 and polymer model 21. Examples of the interaction between the filler model 11 and the polymer model 21 include a chemical interaction such as an attractive force and a repulsive force such as an intermolecular force and a hydrogen bond, and a physical interaction such as a covalent bond. . The interaction between the filler model 11 and the polymer model 21 is set as needed between the filler particles 11a, between the polymer particles 21a, and between the filler particles 11a and the polymer particles 21a. Therefore, it is not necessarily set to all the filler particles 11a and the polymer particles 21a. When the polymer model 21 includes a plurality of types of polymer particles 21a, an interaction may be set for each of the plurality of types of polymer particles 21a. Further, the interaction between each of the plurality of types of polymer particles 21a and the filler model 11 may be the same or different.

  Next, in a second step ST12, a predetermined threshold value is set for the distance between the polymer particles 21a. As the distance between the particles, the length of the bonding chain 21b connecting the polymer particles 21a may be used, or the linear distance between the pair of polymer particles 21a may be used. In the present embodiment, an example will be described in which the predetermined threshold value is set for the distance between the pair of polymer particles 21a to be analyzed in the second step ST12, but the present invention is not limited to this. The threshold value of the distance between particles may be set to the distance between particles between the pair of filler particles 11a according to the composite material to be analyzed.

  Next, in the third step ST13, when the inter-particle distance of the polymer particles 21a is equal to or larger than a predetermined threshold, the bonding between the polymer particles 21a is broken.

  Next, in a fourth step ST14, a numerical analysis of the analysis model is executed by changing the bond energy or bond force of the bond between the particles of the polymer particles 21a that have been subjected to the breaking treatment in accordance with the elapsed time. Specifically, in the fourth step ST14, by rapidly changing the bonding energy or the bonding force of the bonding between the particles according to the elapsed time, it is possible to alleviate the sudden shrinkage of the bonding chain after the breaking treatment.

  The effect of changing the bonding force of the interparticle bonding according to the elapsed time will be described with reference to FIGS. FIGS. 3 to 6 show a case where the bonding force of the interparticle bond is changed. However, the same effect as in the case of changing the bonding force can be obtained by changing the bonding energy of the interparticle bond. Can be.

  FIG. 3 is a diagram for explaining the relationship between the length of the binding chain and the binding force. FIG. 3 shows a graph L1 in which the horizontal axis represents the length of the binding chain and the vertical axis represents the binding force.

  In the graph L1, a time point P1 indicates a time point at which the binding chain is cleaved. In this case, when the binding chain is cut at the time point P1, the force applied to the binding chain rapidly decreases to 0 and reaches the time point P2. In this case, the binding chains contract rapidly.

  FIG. 4 is a schematic diagram for explaining a state of a binding chain. In FIG. 4, the first polymer particles 21a-1, the second polymer particles 21a-2, the third polymer particles 21a-3, the fourth polymer particles 21a-4, the fifth polymer particles 21a-5, and the The description will be made assuming that the polymer chains 21a-6 form the extended chains. In this case, the first polymer particles 21a-1 and the second polymer particles 21a-2 are bonded by a first bonding chain 21b-1. The second polymer particles 21a-2 and the third polymer particles 21a-3 are bonded by a second bonding chain 21b-2. The third polymer particles 21a-3 and the fourth polymer particles 21a-4 are bonded by a third bonding chain 21b-3. The fourth polymer particles 21a-4 and the fifth polymer particles 21a-5 are bonded by a fourth bonding chain 21b-4. The fifth polymer particles 21a-5 and the sixth polymer particles 21a-6 are bonded by a fifth bonding chain 21b-5.

  In such a polymer model, for example, at a time point P1 shown in FIG. 3, the polymer model is an extended chain (step ST101). Here, when the time point P1 is set as a threshold value and the time point P1 is exceeded, the breaking process is performed on the first binding chain 21b-1 that connects the first polymer particle 21a-1 and the second polymer particle 21a-2.

  In this case, the force rapidly decreases and reaches time point P2. After time point P2, the second polymer particles 21a-2, the third polymer particles 21a-3, the fourth polymer particles 21a-4, and the fifth The polymer particles 21a-5 and the sixth polymer particles 21a-6 contract rapidly (step ST102).

  There is a problem that the stress of the system is suddenly reduced when the extended chain is rapidly contracted. When a simulation is performed in such a situation, there is a problem that reproducibility of the stress-strain curve is poor. Therefore, in the present embodiment, the binding energy or the binding force between the polymer particles subjected to the cutting process is made time-dependent, so that the system stress is prevented from suddenly lowering.

  FIG. 5 is a diagram for explaining the relationship between the length of the binding chain and the binding force when the force acting on the binding chain on which the cutting process has been performed is made time-dependent. FIG. 5 shows a graph L2 in which the horizontal axis represents the length of the binding chain and the vertical axis represents the binding force.

  In the graph L2, a time point P3 indicates a time point at which the binding chain is cleaved. In this case, when the binding chain is cut at the time point P3, the force applied to the binding chain rapidly decreases to 0 and reaches the time point P4. Here, the state where the coupling force is 0 continues over the period T. Thereby, the sudden contraction of the extended chain can be suppressed.

  FIG. 6 is a schematic diagram for explaining a state of a binding chain. The configuration of the polymer model shown in FIG. 6 is the same as the configuration of the polymer model shown in FIG.

  In the polymer model shown in FIG. 6, for example, at the time point P3 shown in FIG. 5, the polymer model is an extended chain (step ST201). Here, at the time point P3, a breaking process is performed on the first bonding chain 21b-1 that connects the first polymer particles 21a-1 and the second polymer particles 21a-2.

  In this case, the force drops rapidly and reaches time point P4. In the present embodiment, since the state where the force is 0 continues, the extended chains do not rapidly shrink, and the distance between the first polymer particles 21a-1 and the second polymer particles 21a-2 is slightly reduced. It extends (step ST202).

  Next, the state where the coupling force is 0 continues, and the time point P5 is reached. At time point P5, the distance between the first polymer particles 21a-1 and the second polymer particles 21a-2 is slightly longer than at time point P4 (step ST203). Further, at the time point P5, the second polymer particles 21a-2 to the sixth polymer particles 21a-6 contract slightly more than at the time point P4.

  Then, the time reaches the time point P6, and after the time point P6, the distance between the first polymer particles 21a-1 and the second polymer particles 21a-2 increases (step ST204). Further, the second polymer particles 21a-2, the third polymer particles 21a-3, the fourth polymer particles 21a-4, the fifth polymer particles 21a-5, and the sixth polymer particles 21a-6 contract. . Here, the distance between the first polymer particles 21a-1 and the second polymer particles 21a-2 in step ST204 of FIG. 6 is equal to the distance between the first polymer particles 21a-1 and the second polymer particles 21a-1 in step ST102 of FIG. It is longer than the distance between the particles 21a-2.

  The relationship between the elapsed time when the binding force is 0 and the binding chains (the distance between the first polymer particles 21a-1 and the second polymer particles 21a-2) will be described with reference to FIG. FIG. 7 is a diagram illustrating an example of the relationship between the elapsed time and the length of the binding chain. Specifically, in FIG. 7, the horizontal axis represents the elapsed time, and the vertical axis represents the length of the binding chain when the binding force is not zero.

  In the present embodiment, for example, as the time when the binding force is 0 is increased, the length of the binding chain can be increased, and the time until the fully extended chain contracts can be increased. Here, the user may arbitrarily set the length of time during which the state where the binding force is kept at 0 or how to change the length of the binding chain. For example, as shown in graphs L3 and L4 shown in FIG. 7, the length of the extended chain may be changed linearly. In this case, for example, as shown in a graph L3, the state of the binding force of 0 may be released in a relatively short time (T1) by changing the length of the binding chain relatively slowly. Further, as shown in a graph L4, the length of the binding chain may be changed relatively steeply to change the state where the binding force is 0 for a relatively long time (T2).

  In FIG. 7, the length of the binding chain is linearly changed, but this is merely an example and does not limit the present invention. In the present embodiment, the length of the binding chain may be changed, for example, in a quadratic function, an exponential function, or a logarithmic function. That is, the way of changing the length of the binding chain is arbitrary.

  As described above, in the present embodiment, the contraction of the extended chain after the cutting process becomes gentler than that in the related art. As a result, in the present embodiment, it is possible to accurately reproduce the decrease in rigidity due to the fracture.

  Specifically, in the present embodiment, a predetermined threshold value is set for the distance between the particles of the pair of polymer particles 21a, and when the distance between the particles is equal to or greater than the threshold value, Then, the inter-particle bond is calculated using a function for a break bond calculation that reduces the bond energy and the bond force of the inter-particle bond. For example, the function shown in the following equation (1) is used as the function for calculating the breakage coupling. By using the function for calculating the breaking bond, when the distance between the polymer particles is less than a predetermined threshold value, the binding energy and the bonding force increase and decrease according to the distance between the pair of polymer particles 21a, and the distance between the particles Is greater than or equal to a predetermined threshold value S, the binding energy and binding force become zero. It should be noted that the following equation (1) can be appropriately changed within a range in which the effects of the present invention are exhibited. In the following, an example in which the binding energy is reduced will be described. However, the same can be applied to a case where the binding force is reduced.

  As described above, according to the above-described embodiment, in a region where the distance between particles is equal to or larger than the threshold, at least one of the binding energy and the bonding force of the bonding between particles is reduced, so that the analysis model can be used without breaking the bonding between particles. It is possible to continue the numerical analysis of. This can prevent the physical disappearance of the inter-particle bond due to the breakage, so that it is possible to reproduce a pseudo cut without physically eliminating the inter-particle bond. Therefore, it is possible to realize a method of analyzing a composite material, which can specify a broken portion of a bond between particles broken during a numerical analysis.

  Further, in the above-described embodiment, an example has been described in which, when the inter-particle distance of the polymer particles 21a is equal to or larger than a threshold, the predetermined inter-particle bond calculation function is applied to calculate the inter-particle bond, but the present invention is not limited to this. Absent. For example, when the time average value of the distance between particles becomes equal to or more than a threshold value, even if a numerical analysis of the analysis model 1 is performed using a function for calculating a fracture bond that reduces the bond energy and the bond strength of the bond between particles. Good. Thereby, for example, the calculation using the function for the rupture bond calculation that lowers the bond energy and bond force of the bond between the particles in the pair of polymer particles 21a in which the distance between the particles temporarily exceeds the threshold value due to Brownian motion or the like is performed. Can be excluded. As a result, it is possible to accurately reproduce the breaking of the interparticle bond in the actual composite material.

  By the way, when there are a plurality of pairs of polymer particles 21a connected by interparticle bonding, after the numerical analysis of the analysis model 1, the distance between the plurality of pairs of polymer particles 21a becomes the threshold value S or more sequentially. Then, at least one of the bonding energy and the bonding force of the interparticle bonding is sequentially reduced. In this case, even if the coordinates of the polymer model 21 in which at least one of the bonding energy and the bonding force of the interparticle bonding is reduced are specified, it may not always be possible to sufficiently evaluate each accurate breaking position.

  Therefore, in the above embodiment, the coordinates of the inter-particle bond at the time when the inter-particle distance becomes equal to or larger than the threshold may be specified and evaluated as the breaking position. 8A to 8C are explanatory diagrams of the breaking position of the interparticle bond in the model creation region A. 8A shows the state of the first analysis time T1, FIG. 8B shows the state of the second analysis time T2, and FIG. 8C shows the state of the third analysis time T3.

In the present embodiment, for a plurality of analysis times, the position of the bond between particles in which the bond energy and the bond strength of the bond between particles are reduced is specified. In the example shown in FIG. 8A, in the first analysis time T1, the polymer model 21A has a fractured bond chain 21bx in which the interparticle distance becomes equal to or larger than the threshold value S in the vicinity of the filler model 11 and the binding energy or the binding force is reduced. . In the polymer models 21B and 21C existing near the filler model 11, the distance between the polymer particles 21a is less than the threshold value S, and the bonding chains 21b remain. In the first analysis time T1, identifies the coordinates of the model polymer 21A as breaking coordinates _{X 1.}

Next, at the second analysis time T2 after the elapse of the predetermined time, in the polymer model 21B, the inter-particle distance becomes greater than or equal to the threshold value S in the vicinity of the filler model 11, and the broken bond chains 21bx in which the binding energy or the binding force is reduced are generated. I have. In the polymer model 21C existing in the vicinity of the filler model 11, the distance between the polymer particles 21a is smaller than the threshold value S, and the bonding chains 21b remain. On the other hand, in the polymer model 21A separated from the filler model 11 due to the movement, the broken bond chains 21bx in which the binding energy or the binding force is reduced are maintained. In the second analysis time T2, to identify the coordinates of the model polymer 21B as a new fracture coordinates X _2, the current coordinates of the model polymer 21A which is already broken tether 21bx generated in the first analysis period T1 as a new fracture coordinates Do not specify.

  Further, at the third analysis time T3 after the elapse of the predetermined time, in the polymer model 21C, the distance between the particles becomes equal to or larger than the threshold value S in the vicinity of the filler model 11, and the broken bond chains 21bx having reduced bond energy or bond force are generated. . In the polymer models 21A and 21B separated from the surface of the filler model 11 by the movement, the inter-particle bond of the polymer particles 21a becomes equal to or larger than the threshold value S, and the broken bond 21 chain bx is maintained. At the third analysis time T3, the coordinates of the polymer model 21C are newly specified as breaking coordinates X3. Then, the current coordinates of the polymer model 21A in which the broken bond chain 21bx has already occurred in the first analysis time T1 and the current coordinates of the polymer model 21B in which the break bond chain 21bx has already occurred in the second analysis time T2 are not specified as the break coordinates.

Thus, by the distance between the particles in the first analysis time T1~ third in analysis time T3 successive sequentially identifies the break coordinate X ₁ to X ₃ in which equal to or larger than the threshold value S, for example, as shown in FIG. 9 Then, the distance from the surface of the filler model 11 and the coordinate distribution of the fracture coordinates are obtained. Thus, in the numerical analysis of the analysis model 1 shown in FIGS. 8A to 8C, it can be seen that the coordinate distribution of the fracture coordinates X _{1 to} X ₃ increases as the distance from the filler model 11 decreases. From this result, as shown in FIG. 9, it is possible to evaluate a place where the bond between particles is easily broken, so that it is possible to evaluate the relationship between the distance from the surface of the filler model 11 and the breaking probability.

  In addition, in the example shown in FIGS. 8A to 8C, a representative point may be set for the inter-particle bond to specify the fracture position (fracture coordinate). For example, in the example shown in FIG. 8A, the center of gravity (middle point) of the pair of polymer particles 21a in the bond chain 21b, which is an interparticle bond, or an end point overlapping with the coordinates of the polymer particle 21a is specified as a representative point as the break position. . This makes it possible to evaluate the coordinates of the representative point of the interparticle bond whose length has increased as the breaking position, and thus facilitates the evaluation of the breaking position.

In addition, in the examples illustrated in FIGS. 8A to 8C, the inter-particle coupling in which the inter-particle distance is equal to or more than a predetermined value may be visualized. This makes it possible to visually confirm the broken bond chain 21bx, which is the inter-particle bond between the pair of pseudo-broken polymer particles 21a, so that it is easy to identify the broken portion of the broken inter-particle bond during numerical analysis. Become. Similarly, the fracture coordinates X ₁ to X ₃ to break tether 21bx to break interparticle binding occurs may be visualized. Thereby, the place easily broken can be visually evaluated, so that the place easily broken can be easily evaluated. Further, the representative points may be visualized. Thereby, since the representative point is visualized without visualizing the entire length of the inter-particle bonds, the broken inter-particle bonds can be easily confirmed. The visualization of the inter-particle bond may be performed, for example, by hiding the bond chain 21b other than the broken bond chain 21bx, increasing the transparency of the bond chain 21b, and changing the color and thickness of the broken bond chain 21bx to those of the bond chain 21b. It may be changed and displayed. As a result, the broken bond chain 21bx can be emphasized, and can be easily visually confirmed.

  In the above-described embodiment, the visualization may be executed at a plurality of analysis times during the numerical analysis. 10A to 10C are explanatory diagrams of an example of visualization at three analysis times of the first analysis time T1 to the third analysis time T3. In FIGS. 10A to 10C, fracture coordinates X1 to X3 in which the distance between the pair of polymer particles 21a is equal to or larger than the threshold are schematically illustrated in a substantially spherical shape.

  In the example shown in FIGS. 10A to 10C, as shown in FIG. 10A, a fracture coordinate X1 is generated near the filler model 11 at the first analysis time T1 and is visualized. Then, as shown in FIG. 10B, at the second analysis time T2, the fracture coordinates X1 generated at the first analysis time T1 move together with the filler model 11 while the relative position with respect to the filler model 11 is maintained. At the same time, the fracture coordinates X2 generated at the second analysis time T2 are newly visualized near the filler model 11. Further, at the third analysis time T3, the fracture coordinates X1 generated at the first analysis time T1 and the fracture coordinates X2 generated at the second analysis time T2 are together with the filler model 11 in a state where the relative position with respect to the filler model 11 is maintained. Moving. At the same time, the fracture coordinates X3 generated at the third analysis time T3 are newly visualized near the filler model 11. By visualizing in this manner, even when the position of the filler model 11 is changed according to the coordinates at the first analysis time T1 to the third analysis time T3, the fracture coordinates generated around the filler model 11 It is possible to display while maintaining the relative coordinates of X1 to X3. As a result, it is possible to reproduce the breaking of the bond between particles of the polymer model 21 around the filler model 11.

  Further, in the above embodiment, the numerical analysis is performed on each of the plurality of polymer models 21 or the filler models 11 included in the analysis model 1, and the obtained results of the plurality of numerical analyzes are collectively visualized and evaluated. May be. 11A and 11B are explanatory diagrams of an example in which two analysis times of a first analysis time T1 and a second analysis time T2 are aggregated and visualized. In the present embodiment, a first filler model 11A and a second filler model 11B are present in the model creation region A, and numerical analysis is performed on each of the first filler model 11A and the second filler model 11B.

  As shown in FIG. 11A, at the first analysis time T1, the breaking of the interparticle bond of the polymer model 21 occurs near the first filler model 11A, and one breaking coordinate X1 is visualized near the first filler model 11A. Is done. Also, as shown in FIG. 11B, the first filler model 11A and the second filler model 11B move in the model creation area A at the second analysis time T2. Further, at the second analysis time T2, the breaking of the interparticle bond of one polymer model 21 occurs near the first filler model 11A and near the second filler model 11B, respectively. Then, the breaking coordinates X2 are visualized near the first filler model 11A and newly added, and the breaking coordinates X3 are newly visualized near the second filler model 11B. As a result, at the second analysis time T2, three fracture coordinates X1 and X2 generated near the first filler model 11A and one fracture coordinate X3 generated near the second filler model 11B are three fracture coordinates X1 to X1. X3 are displayed collectively.

  As described above, in the present embodiment, the two first filler models 11A and the second filler models 11B in the analysis model 1 can be displayed collectively in one model creation area A, so that an analysis result can be obtained quickly. And the analysis results are easily understood.

  In the examples shown in FIGS. 11A and 11B, the numerical analysis may be executed for each of the plurality of polymer models 21 or the filler models 11 included in the analysis model 1. In this case, the obtained results of the plurality of numerical analyzes may be collected into a specific first filler model 11A designated in the analysis model 1 and visualized for evaluation.

  As shown in FIG. 12, the method of analyzing a composite material according to the present embodiment includes a step of creating an analysis model, a first step ST21, a second step ST22, a third step ST23, and a fourth step ST23. It includes ST24 and a fifth step ST25. Here, the first step ST21, the third step ST23, the fourth step ST24, and the fifth step ST25 are respectively a first step ST11, a second step ST12, a third step ST13, and a fourth step ST13. The description is omitted because it is the same as ST14.

  In the case of FIG. 12, in the second step ST22, after the analysis model is created, the polymer model 21 is crosslinked. As a result, the method for analyzing a composite material can perform a numerical analysis of the analysis model in a state where the polymer model is previously cross-linked through a cross-linking reaction. Analysis becomes possible.

  Next, the method for analyzing a composite material, the computer program for creating a model for analyzing a composite material, the method for analyzing a composite material, and the computer program for analyzing a composite material according to the present embodiment will be described in more detail. FIG. 13 is a functional block diagram of a composite material analysis method and an analysis device that executes the composite material analysis method according to the present embodiment.

  As shown in FIG. 13, the method for analyzing a composite material according to the present embodiment is implemented by an analysis device 50 that is a computer including a processing unit 52 and a storage unit 54. The analysis device 50 is electrically connected to an input / output device 51 having an input unit 53. The input means 53 processes various physical property values of the polymer and the filler for which the model for the analysis of the composite material is created, the actual measurement result of the extension test result using the composite material containing the polymer and the filler, and the boundary condition in the analysis. It is input to the unit 52 or the storage unit 54. As the input unit 53, for example, an input device such as a keyboard and a mouse is used.

  The processing unit 52 includes, for example, a central processing unit (CPU: Central Processing Unit) and a memory. The processing unit 52 reads a computer program from the storage unit 54 when executing various processes, and expands the computer program in the memory. The computer program developed in the memory executes various processes. For example, the processing unit 52 develops data relating to various processes stored in advance from the storage unit 54 in an area allocated to itself on a memory as needed. Then, the processing unit 52 executes various processes related to creation of a composite material analysis model based on the developed data and analysis of the composite material using the composite material analysis model.

  The processing unit 52 includes a model creation unit 52a, a condition setting unit 52b, and an analysis unit 52c. The model creation unit 52a is based on data stored in advance in the storage unit 54, and based on the data, the number of particles, the number of molecules, and the molecular weight of the composite material such as filler and polymer when creating the composite material analysis model 1 by the molecular dynamics method. Configuration, number of molecular chains, number of molecular chains, branching, shape, size, reaction time, reaction conditions and the number of steps such as target number of molecules included in the model for analysis Of the coarse-grained model is set. The model creation unit 52a also sets initial conditions of various calculation parameters such as interactions between filler particles 11a, between polymer particles 21a, and hydrogen bonds between filler / polymer particles, intermolecular forces and the like. In addition, the model creation unit 52a may create a cross-linking analysis such as creation of a cross-link by cross-linking the polymer model 21 as necessary.

  As calculation parameters for adjusting the interaction between the filler particles 11a and the interaction between the polymer particles 21a, σ and ε of the Leonard-Jones potential expressed by the following equation (2) are used, and these are adjusted. By increasing the upper limit distance (cutoff distance) for calculating the potential, it is possible to adjust the attractive force and the repulsive force that have been applied to a long distance. It is preferable that the parameters of the interaction between the filler particles 11a and the interaction between the polymer particles 21a are sequentially reduced until the interaction between the filler particles 11a and the interaction between the polymer particles 21a become constant. By gradually increasing the σ and ε of the Leonard-Jones potential from large values to the original values, particles can approach at a gentle speed that does not lead the molecules to an unnatural state. In addition, by gradually reducing the cutoff distance, the attractive force and the repulsive force can be adjusted within an appropriate range.

  The condition setting unit 52b sets various numerical analysis conditions such as numerical analysis such as temperature change analysis and pressure analysis, deformation analysis such as extension analysis and shear analysis, and motion analysis such as relaxation analysis.

  The analysis unit 52c performs various numerical analyzes of the analysis model 1 based on the analysis conditions set by the condition setting unit 52b. The analysis unit 52c executes a numerical analysis by a molecular dynamics method using the composite material analysis model 1 created by the model creation unit 52a to acquire a physical quantity. Here, the analysis unit 52c executes, as numerical analysis, deformation analysis such as extension analysis and shear analysis, and motion analysis such as relaxation analysis. In addition, the analysis unit 52c acquires a value such as a displacement obtained as a result of the numerical analysis or a physical quantity such as a distortion obtained by performing a predetermined calculation process on the obtained value.

  In addition, the analysis unit 52c acquires various physical quantities such as a nominal displacement or a nominal strain obtained by calculating a nominal displacement or a nominal displacement obtained as a result of the numerical analysis. By such numerical analysis and motion analysis, segments such as the bond length of the polymer molecule and the polymer particle speed, the speed or the bond length between the cross-linking points and the free end, and the physical quantity such as the orientation, which change with the analysis time for the entire analysis model. It is possible to evaluate the relationship between the numerical value representing the state change and the distortion. In addition, it is possible to evaluate a relationship between a numerical value representing a change in the state of a segment such as a bond length of a polymer molecule and a velocity of a polymer particle that changes every analysis time, and a pressure or an analysis time. Furthermore, it is possible to evaluate a relationship between a numerical value representing a change in the state of a segment such as a bond length of a polymer molecule and a polymer particle velocity which changes every analysis time, and a temperature or an analysis time. As a result, a more detailed analysis of a local molecular state change of the polymer molecule becomes possible.

  In addition, the analysis unit 52c specifies the breaking coordinates of the polymer model 21 obtained by the numerical analysis, and evaluates the specified breaking coordinates. Here, the analysis unit 52c may visualize and evaluate the broken inter-particle bonds, or may visualize and evaluate the fracture coordinates. Further, the analysis unit 52c may aggregate and evaluate the fracture coordinates generated around the plurality of filler models 11, and may aggregate the fracture coordinates generated around the plurality of filler models 11 into one representative filler model. May be evaluated. In addition, the analysis unit 52c may aggregate and evaluate the analysis results separately analyzed using the plurality of analysis models 1. The analysis unit 52c stores the analysis result of the analyzed composite material in the storage unit 54.

  The storage unit 54 is a non-volatile memory that is a read-only recording medium such as a hard disk device, a magneto-optical disk device, a flash memory, and a CD-ROM, and a read / write unit such as a RAM (Random Access Memory). Volatile memories, which are possible recording media, are appropriately combined.

  The storage unit 54 includes data of fillers such as rubber carbon black, silica, and alumina, which are data for creating an analysis model of a composite material to be analyzed via the input unit 53, rubber, resin, and elastomer. The data of the polymer such as is stored. Further, the storage unit 54 stores a stress-strain curve, which is a physical quantity history set in advance, a method for analyzing a composite material according to the present embodiment, a computer program for implementing the method for analyzing a composite material, and the like. This computer program may be capable of realizing the method for analyzing a composite material according to the present embodiment by a combination with a computer program already recorded in a computer or a computer system. Here, the “computer system” includes an OS (Operating System) and hardware such as peripheral devices.

  The display unit 55 is, for example, a display device such as a liquid crystal display device. Note that the storage unit 54 may be in another device such as a database server. For example, the analysis device 50 may access the processing unit 52 and the storage unit 54 by communication from a terminal device including the input / output device 51.

(Example)
Next, examples performed to clarify the effects of the present invention will be described. In addition, this invention is not limited at all by the following Examples.

  A method for analyzing a composite material according to an example of the present embodiment will be described with reference to FIG. FIG. 14 is a flowchart illustrating an example of a method for analyzing a composite material according to an example of the present embodiment. In the following, each step will be described as being executed by the analyzer 50 illustrated in FIG.

  First, the analysis device 50 creates an analysis model for performing a numerical analysis (step ST31). Then, the analysis device 50 proceeds to step ST32.

  Next, the analysis device 50 creates a crosslink of the polymer model included in the analysis model (step ST32). Then, the analysis device 50 proceeds to step ST33.

  Next, the analysis device 50 sets an interaction between the filler contained in the analysis model and the polymer (step ST33). Then, the analysis device 50 proceeds to step ST34.

  Next, the analysis device 50 sets an interaction between the polymer included in the analysis model and the polymer (step ST34). Then, the analysis device 50 proceeds to step ST35.

  Next, the analysis device 50 selects a material (bonded chain) to be considered for cutting included in the analysis model (step ST35). Then, the analysis device 50 proceeds to step ST36.

  Next, the analysis device 50 performs a numerical analysis according to the conditions set in steps ST31 to ST35 (step ST36). Then, the analysis device 50 proceeds to step S37.

  Next, the analysis device 50 evaluates the breaking characteristics of the analysis model based on the result of the numerical analysis in step ST36 (step ST37). Then, the analysis device 50 ends the processing of FIG.

  FIG. 15 is a diagram illustrating a stress-strain curve according to the present example. As shown in FIG. 15, when the method for analyzing a composite material according to the example is used (Example 1: see graph L11), a stress-strain curve is measured using an actual composite material (Experimental Example 1). Similarly to the graph L14), after the strain increased to a constant value together with the stress, the stress was maintained substantially constant. In contrast, when a conventional numerical analysis was performed (Comparative Example 1: see graph L12), a result was obtained in which the stress increased, the strain increased to a certain value, and then the stress significantly decreased. In addition, when the fracture of the bonding chain 21b was not considered (Comparative Example 2: see the graph L13), the strain continuously increased with an increase in the stress. According to the result, in the example, the same result as the experimental example 1 was obtained because the contraction speed of the molecular chain of the polymer model 21 could be reduced by making the binding energy or the strength of the binding force between the particles time-dependent. It is thought that it was.

1 Analytical Model 11, 11A, 11B, 11C, 11D Filler Model 11a Filler Particle 21, 21A, 21B, 21C Polymer Model 21a Polymer Particle 21b Binding Chain 21bx Breaking Binding Chain 50 Analysis Device 51 Input / Output Device 52 Processing Unit 52a Model Creation Unit 52b condition setting unit 52c analysis unit 53 input unit 54 storage unit 55 display unit A model creation area X1, X2, X3 breaking coordinates

Claims (19)

A method for analyzing a composite material by a molecular dynamics method using a computer,
Said computer,
A first step of creating a specific substance analysis model including a specific substance model obtained by modeling the specific substance;
Belong to a specific substance model to be analyzed, a second step of setting a threshold value for the inter-particle distance of at least one pair of particles coupled by inter-particle bonding,
A third step of breaking the interparticle bond when the interparticle distance is equal to or greater than the threshold,
A fourth step of performing a numerical analysis of the analysis model by changing the binding energy or the binding force of the fracture-processed interparticle bond according to elapsed time,
A method for analyzing a composite material, comprising: In the fourth step, the computer changes only the binding energy or the binding force at a distance equal to or greater than the breaking threshold with time.
The method for analyzing a composite material according to claim 1. The computer includes a step of cross-linking the specific substance model between the first step and the second step,
The method for analyzing a composite material according to claim 1. In the second step, the computer sets a threshold range having a numerical range as the threshold,
The method for analyzing a composite material according to claim 1. The breaking process is a pseudo breaking process using a breaking connection calculation function,
The method for analyzing a composite material according to claim 1. The breaking bond calculation function is to reduce at least one of the bond energy and the bond force of the interparticle bond from the lower limit of the threshold range toward the upper limit.
The method for analyzing a composite material according to claim 5. The computer, in the fourth step, when the inter-particle distance is less than the threshold, performs the numerical analysis using an operation function different from the fracture bonding operation function, and the inter-particle distance is the threshold. In the above case, the numerical analysis is performed using the break connection calculation function,
The method for analyzing a composite material according to claim 5. The computer, in the fourth step, when the time average value of the distance between the particles is equal to or more than a predetermined value, executes the numerical analysis using the function for calculating the fracture bond,
The method for analyzing a composite material according to claim 5. The breaking bond calculation function is to substantially eliminate at least one of the bond energy and the bond force of the interparticle bond,
The method for analyzing a composite material according to claim 5. The computer, in the fourth step, the coordinates of the interparticle bond at the time when the distance between the particles is equal to or more than the threshold is specified and evaluated as breaking coordinates,
The method for analyzing a composite material according to claim 1. In the fourth step, the computer specifies a breakpoint by setting a representative point in the interparticle bond,
The method for analyzing a composite material according to claim 10. The computer visualizes the representative point in the fourth step,
A method for analyzing a composite material according to claim 11. The computer visualizes the breaking coordinates in the fourth step,
The method for analyzing a composite material according to claim 10. The computer, in the fourth step, visualizes the inter-particle bond in which the inter-particle distance is equal to or greater than the threshold,
The method for analyzing a composite material according to claim 1. In the fourth step, the computer executes the visualization at a plurality of analysis times during the numerical analysis,
The method for analyzing a composite material according to claim 12. In the fourth step, the computer executes the numerical analysis on each of a plurality of first material models or second material models included in the analysis model, and aggregates a plurality of obtained numerical analysis results. Visualize and evaluate,
The method for analyzing a composite material according to claim 1. In the fourth step, in the fourth step, a plurality of results of the numerical analysis are aggregated into a specific first material model or a representative model of the second material model designated in the analysis model, and the result is visualized and evaluated.
The method for analyzing a composite material according to claim 16. The specific substance includes a polymer and a filler,
The method for analyzing a composite material according to claim 1.   A computer program for analyzing a composite material, the program causing a computer to execute the method for analyzing a composite material according to any one of claims 1 to 18.

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