JP6243774B2 - Generation device, generation method and computer program of crosslinked particle model for molecular dynamics calculation. - Google Patents

Description

  The present invention relates to an apparatus, a generation method, and a computer program for generating a crosslinked particle model for molecular dynamics calculation used for calculating viscoelasticity.

  For example, it is difficult to observe the crosslinking distribution by experiment for vulcanized rubber vulcanized by adding a crosslinking agent such as sulfur to unvulcanized rubber. It is known that the cross-linking distribution affects viscoelasticity, and it would be preferable for research and development if it was possible to analyze the relationship between the cross-linking distribution of particles and viscoelasticity by computer simulation using CAE (Computer Aided Engineering). Conceivable. However, a method for controlling the cross-linking distribution of particles has not been established yet.

  For example, Non-Patent Document 1 discloses, as a document seeking a method for controlling the crosslinking distribution of particles, that a crosslinkable particle is designated for a molecular chain model in which a plurality of monomer particles are linked together. The setting of the crosslinkable particles is performed by designating the number of non-crosslinkable particles arranged between the crosslinkable particles. According to this, for example, when the first and 80th crosslinkable particles are designated, the particles in between are set as non-crosslinkable particles. It has been disclosed to make the distribution of crosslinks non-uniform by changing the number of non-crosslinkable particles placed between the crosslinkable particles. The molecular chain model is subjected to crosslinking treatment (reaction treatment) by molecular dynamics calculation.

  In addition, as another document for searching for a method for controlling the crosslinking distribution of particles, Non-Patent Document 2, for example, attempts to express the density of crosslinking by arranging clusters in which a plurality of particles are crosslinked and crosslinking the clusters. Is disclosed.

FY2009-2011 Results Report Nanotechnology / Advanced Materials Research and Development “Research and Development of Rubber Materials for Ultra-Low Fuel Efficiency Tires by Controlling Three-dimensional Nano Hierarchical Structure”, February 2012, National Institute of Advanced Industrial Science and Technology, pages 8-9 "Molecular modeling of crosslink distribution in epoxy polymers", A. Bandyopadhyay and G.M.Odegard Department of Mechanical Engineering-Engineering Mechanics Michigan Technological University, Modeling and Simulation in Materials Science and Engineering, Vol.20, 045018 (2012).

  However, the inventors of the present invention set a particle model based on the description in the non-patent document and generated a crosslinking model by molecular dynamics calculation. However, the method described in the non-patent document has a problem. I understood.

  Non-Patent Document 1 shows that even if the crosslinkable particles for the particle model are distributed, the crosslinked particles are spatially randomly distributed, and the crosslinked particles are spatially non-uniformly distributed. It turned out not to be.

  In Non-Patent Document 2, it was found that a regular structure is formed as a result of crosslinking between regularly arranged crosslinked clusters.

  The present invention has been made paying attention to such problems, and its purpose is to control the cross-linking distribution of molecular chains, and to generate a cross-linked particle model having a spatially non-uniform cross-linking distribution. An apparatus, a method, and a computer program are provided.

  In order to achieve the above object, the present invention takes the following measures.

  That is, the molecular particle dynamic cross-linking model generating apparatus of the present invention has a predetermined cross-linking probability that represents the probability of cross-linking with the cross-linking agent particle for each particle constituting the linear or branched polymer particle model. Setting and setting at least three consecutive particles as preferentially crosslinked particles having a higher crosslinking probability than the surrounding particles, and performing molecular dynamics calculation based on preset analysis conditions, the polymer A reaction process execution unit that executes a reaction process for combining the particles with a crosslinking probability set to the particles when the particles of the particle model approach the cross-linking agent particles within a predetermined distance.

  The method for generating a crosslinked particle model for molecular dynamics calculation according to the present invention is a computer-executed method, and the probability that each particle constituting a linear or branched polymer particle model is crosslinked with a crosslinking agent particle. And setting a predetermined cross-linking probability representing at least three consecutive particles as preferential cross-linking particles having a higher cross-linking probability than surrounding particles, and molecular dynamics based on preset analysis conditions Performing a calculation process, and executing a reaction process for combining the particles with the cross-linking probability corresponding to the particles when the particles of the polymer particle model approach the cross-linking agent particles within a predetermined distance.

  According to the present invention, a predetermined cross-linking probability is set for each particle constituting the polymer particle model, and at least three continuous particles have a high cross-linking probability as a preferential cross-linking particle compared to the surroundings. As a result, since the crosslinking agent particles are preferentially crosslinked with respect to at least three consecutive preferentially crosslinked particles, the crosslinked particles are spatially unevenly distributed, and the cross-linking distribution of molecular chains is reduced. A particle model that can be controlled and has a spatially non-uniform cross-linking distribution can be generated.

  In order to appropriately perform the reaction treatment, the reaction treatment of the preferential crosslinking particles and the crosslinking agent particles is performed, and then the reaction treatment of all the particles constituting the polymer particle model and the crosslinking agent particles is performed. Is preferred.

  In order to appropriately set the preferentially crosslinked particles, particles are randomly selected from all particles constituting the polymer particle model, and at least three consecutive particles including the selected particles are set as the preferentially crosslinked particles. preferable.

  The present invention can be specified as a program that causes a computer to execute the steps constituting the method.

The block diagram which shows the apparatus which produces | generates the crosslinked-particle model for molecular dynamics of this invention. Explanatory drawing regarding the method of producing | generating the crosslinked particle model for molecular dynamics of this invention. The flowchart which shows the model production | generation process routine performed with the production | generation apparatus of this invention. The figure which shows the mode of distribution of the bridge | crosslinking point by the model obtained by the apparatus and method of this invention, and the model of a prior art. The figure which shows the radial distribution function of the bridge | crosslinking point by the model obtained by the apparatus and method of this invention, and the model of a prior art.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[Crosslinked particle model generator]
The apparatus of the present embodiment is an apparatus that generates a crosslinked particle model for molecular dynamics calculation used for calculating viscoelasticity.

  As illustrated in FIG. 1, the apparatus 1 includes a setting unit 10 and a reaction processing execution unit 11. These units 10 to 11 are configured such that software and hardware cooperate with each other when the CPU executes a model generation processing routine shown in FIG. 3 stored in advance in an information processing apparatus such as a personal computer having a CPU, a memory, various interfaces, and the like. Realized by working.

  The setting unit 10 shown in FIG. 1 accepts an operation from a user via a known operation unit such as a keyboard and a mouse, sets information on a polymer particle model, sets about a crosslinking agent such as sulfur, and molecules necessary for crosslinking. Various analysis conditions used for dynamic calculation are set and stored in the memory.

  The setting unit 10 shown in FIG. 1 has a cross-linking agent particle 3 shown in FIG. 2 (d) for each particle 2 (shown by a circle in the figure) constituting the linear polymer model shown in FIG. 2 (a). A predetermined bridging probability T1 representing the probability of bridging (indicated by a filled circle in the figure) is set. As shown in FIG. 2 (c), the setting unit 10 sets at least three consecutive particles (shown by diagonal lines) as preferentially crosslinked particles 20 having a higher crosslinking probability T2 than surrounding particles (shown by white lines). To do. The crosslinking probability T2 of the preferentially crosslinked particles 20 is higher than the crosslinking probability T1 of the particles 21 other than the preferentially crosslinked particles. Since the effect can be confirmed if at least three preferentially crosslinked particles 20 are continuous, it is sufficient if there are three or more. In the present embodiment, a linear model in which a plurality of particles are connected in series is taken as an example, but the present invention is not limited to this. For example, a branched model having branches may be used.

  Specifically, as shown in FIGS. 2B and 2C, the method for setting the preferentially crosslinked particles 20 is to select particles at random from all the particles 2 constituting the polymer particle model, and continuously including the selected particles. At least three particles are set as preferentially crosslinked particles 20.

  The reaction processing execution unit 11 shown in FIG. 1 performs molecular dynamics calculation based on preset analysis conditions. When the particle 2 of the polymer particle model approaches the cross-linking agent particle 3 within a predetermined distance, the particle 2 A reaction process is performed in which both are bonded with a cross-linking probability (T1, T2) corresponding to.

  Specifically, the reaction treatment of the preferentially crosslinked particles 20 and the crosslinking agent particles 3 is performed as shown in FIG. 2 (e), and then all the particles 2 constituting the polymer particle model as shown in FIG. 2 (f). (20, 21) and the cross-linking agent particle 3 are reacted. In this way, the preferentially crosslinked particles 20 can be preferentially reacted with the crosslinker particles 3, and the polymer particles 21 other than the preferentially crosslinked particles are also taken into consideration when the reaction of the crosslinker particles 3 is not sufficient. Can be reacted.

[Method for generating crosslinked particle model]
A method for generating a crosslinked particle model using the apparatus 1 will be described.

  First, in step ST1 (see FIG. 3), the setting unit 10 shown in FIG. 1 generates a polymer particle model in which a plurality of particles are continuous as illustrated in FIG. 2A based on the set data. .

  In the next step ST2 (see FIG. 3), the setting unit 10 generates a random number as shown in FIG. 2B, and randomly selects particles from all the particles 2 constituting the polymer particle model based on the random number. select.

  In the next step ST3 (see FIG. 3), the setting unit 10 sets at least three consecutive particles including the selected particles as the preferentially crosslinked particles 20, as shown in FIG.

  In the next step ST4 (see FIG. 3), as shown in FIG. 2D, the crosslinking agent particles 3 such as sulfur are generated based on the setting data.

  In the next step ST5 (see FIG. 3), the reaction process execution unit 11 executes a reaction process between the preferentially crosslinked particles 20 and the crosslinking agent particles 3 as shown in FIG. In the reaction process, molecular dynamics calculation is performed based on preset analysis conditions, and when the polymer particle model (preferential cross-linked particle 20) approaches the cross-linking agent particle 3 within a predetermined distance, the preferential cross-linked particle 20 is This is a process of bonding both with a corresponding crosslinking probability T2.

  In the next step ST6 (see FIG. 3), as shown in FIG. 2 (f), the reaction processing execution unit 11 makes all the particles 2 constituting the polymer particle model (other than the preferentially crosslinked particles 20 and the preferentially crosslinked particles 20). The reaction treatment of the particles 21) and the crosslinking agent particles 3 is carried out. In this reaction process, molecular dynamics calculation is performed based on preset analysis conditions, and the polymer particle model (the preferentially crosslinked particles 20 and the particles 21 other than the preferentially crosslinked particles 20) approaches the crosslinker particles 3 within a predetermined distance. In this case, both of them are combined with a crosslinking probability T2 corresponding to the particle 2. In order to perform this process, the setting of the preferentially crosslinked particles 20 is canceled so that all the particles 2 constituting the polymer particle model have the same crosslinking probability T1.

  If steps ST1 to ST6 are executed, a crosslinked particle model in which the crosslinking distribution is controlled by the continuous number of the preferentially crosslinked particles 20 can be obtained.

  In order to confirm the effectiveness of the above apparatus and method, a polymer particle model described below is generated, molecular dynamics calculation is performed using the polymer particle model to obtain a visible image of the particle, ) Radial distribution function. All of the following have the same polymer length.

Comparative Example 1
A polymer particle model was generated with the same probability set so that all polymer particles reacted with the same probability as the crosslinker particle 3.

Comparative Example 2
Based on the description of Non-Patent Document 2, a crosslinked cluster was created, and a polymer particle model was generated in which regularly arranged clusters were crosslinked.

Comparative Example 3
Based on the description in Non-Patent Document 2, only the first, 120th, 240th, 260th, 280th, and 300th particles from the end in the molecular chain are set as crosslinkable particles, and other particles cannot be crosslinked. A polymer particle model set for the particles was generated.

Comparative Example 4
The apparatus and method described in the present invention were used, but two continuous preferentially crosslinked particles 20 were set at 50 locations.

Example 1
Using the apparatus and method described in the present invention, three consecutive preferentially crosslinked particles 20 were set at 50 locations.

Example 2
Using the apparatus and method described in the present invention, five consecutive preferentially crosslinked particles 20 were set at 50 locations.

Example 3
Using the apparatus and method described in the present invention, 11 consecutive preferentially crosslinked particles 20 were set at 50 locations.

  FIG. 4 shows a visible image of a crosslinking point for each of Comparative Examples 1-4 and Examples 1-3. As can be seen from FIG. 4, in Comparative Examples 1 to 3, the crosslinking points are randomly distributed and can be said to be a uniform distribution. In Comparative Example 4, it is difficult to determine whether the cross-linking points are uniformly distributed or non-uniform. In Examples 1 to 3, it can be seen that the crosslinking points are locally concentrated and have a non-uniform distribution.

  FIG. 5 shows the radial distribution function of the crosslinking points for each of Comparative Examples 1 to 4 and Examples 1 to 3. When the radial distribution function is close to 1, it means that the particles are randomly distributed. According to FIG. 5, in Comparative Examples 1 to 4, the radial distribution function is close to 1, and it can be understood that the bridging points have a regular distribution since they are wavy around 1. On the other hand, in Examples 1 to 3, the radial distribution function has a large peak exceeding 1 and then gradually approaches 1. This indicates that aggregates having a size such that the radial distribution function approaches 1 are randomly distributed, and the cross-linking points are unevenly distributed.

  As described above, the generation device of the crosslinked particle model for molecular dynamics calculation according to the present embodiment has a probability of crosslinking with the crosslinking agent particle 3 for each particle 2 constituting the linear or branched polymer particle model. Based on a setting unit 10 that sets a predetermined cross-linking probability T1 to be expressed, and sets at least three consecutive particles as preferential cross-linking particles 20 having a higher cross-linking probability T2 than surrounding particles, and preset analysis conditions Molecular dynamics calculation is performed, and when the particle 2 (20, 21) of the polymer particle model approaches the cross-linking agent particle 3 within a predetermined distance, the crosslinking probability (T1, T2) set for the particle 2 (20, 21) And a reaction process execution unit 11 that executes a reaction process for combining the two in T2).

  The method for generating a crosslinked particle model for molecular dynamics calculation according to the present embodiment is a computer-executed method, in which a crosslinking agent particle 3 and a particle 2 constituting a linear or branched polymer particle model are A step (ST2, ST3) of setting a predetermined cross-linking probability T1 representing the probability of cross-linking and setting at least three consecutive particles as preferential cross-linking particles 20 having a higher cross-linking probability T2 than surrounding particles; Molecular dynamics calculation is performed based on the set analysis conditions, and when the particle 2 (20, 21) of the polymer particle model approaches the cross-linking agent particle 3 within a predetermined distance, it corresponds to the particle 2 (20, 21) And a step (ST5) of executing a reaction process for bonding the two at a crosslinking probability (T1, T2).

  According to the above, a predetermined crosslinking probability T1 is set for each particle 2 constituting the polymer particle model, and at least three consecutive particles have a higher crosslinking probability T2 as the preferential crosslinking particles 20 than the surroundings. Is done. As a result, the crosslinking agent particles 3 are preferentially cross-linked with respect to at least three consecutive preferentially cross-linked particles 20, so that the cross-linked particles are spatially unevenly distributed. Can control the distribution and generate a particle model with spatially non-uniform cross-linking distribution

  In the present embodiment, the reaction process between the preferentially crosslinked particles 20 and the crosslinker particles 3 is performed, and then all the particles 2 (preferentially crosslinked particles 20 and particles 21 other than the preferentially crosslinked particles 20) constituting the polymer particle model are crosslinked. The reaction process of the agent particle 3 is executed.

  In this way, the preferentially crosslinked particles 20 can be preferentially reacted with the crosslinker particles 3, which is preferable in obtaining nonuniformity.

  In the present embodiment, particles are randomly selected from all particles 2 constituting the polymer particle model, and at least three consecutive particles including the selected particles are set as the preferentially crosslinked particles 20.

  In this way, mounting on a computer becomes easy.

  The computer program according to the present embodiment is a program that causes a computer to execute the steps constituting the method. By executing this program, it is possible to obtain the operational effects of the above method. In other words, it can be said that the above method is used.

  As mentioned above, although embodiment of this invention was described based on drawing, it should be thought that a specific structure is not limited to these embodiment. The scope of the present invention is shown not only by the above description of the embodiments but also by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, each of the units 10 to 11 illustrated in FIG. 1 is realized by executing a predetermined program by a CPU of a computer, but each unit may be configured by a dedicated memory or a dedicated circuit.

  Moreover, in this embodiment, after performing the reaction process of the preferential crosslinking particle 20 and the crosslinking agent particle 3, the setting of the preferential crosslinking particle 20 is canceled, and all of the particles 2 and the crosslinking agent particle 3 constituting the polymer particle model are released. Although a reaction process is performed, this process can be omitted.

  The structure employed in each of the above embodiments can be employed in any other embodiment. The specific configuration of each unit is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Setting part 11 ... Reaction process execution part 2 ... Particle | grains which comprise a polymer particle model 20 ... Preferential cross-linking particle 21 ... Particles other than preferential cross-linking particle 3 ... Cross-linking agent particle T1, T2 ... Cross-linking probability

Claims (7)

For each particle constituting the linear or branched polymer particle model, a predetermined crosslinking probability representing the probability of crosslinking with the crosslinking agent particle is set, and at least three consecutive particles are higher than the surrounding particles. A setting unit for setting the preferentially crosslinked particles having a crosslinking probability;
A reaction in which molecular dynamics calculation is performed based on preset analysis conditions, and when the polymer particle model particle approaches the cross-linking agent particle within a predetermined distance, the cross-linking probability set for the particle is coupled to both. An apparatus for generating a crosslinked particle model for molecular dynamics calculation, comprising: a reaction processing execution unit that executes processing.   The apparatus according to claim 1, wherein a reaction process between the preferential crosslinking particles and the crosslinking agent particles is performed, and thereafter, a reaction process between all the particles constituting the polymer particle model and the crosslinking agent particles is performed.   The apparatus according to claim 1 or 2, wherein particles are randomly selected from all particles constituting the polymer particle model, and at least three consecutive particles including the selected particles are set as the preferentially crosslinked particles. A method performed by a computer,
For each particle constituting the linear or branched polymer particle model, a predetermined crosslinking probability representing the probability of crosslinking with the crosslinking agent particle is set, and at least three consecutive particles are higher than the surrounding particles. Setting to preferentially crosslinked particles having a crosslinking probability;
A molecular dynamics calculation based on preset analysis conditions, and when the particles of the polymer particle model approach the cross-linking agent particles within a predetermined distance, a reaction that combines them with the cross-linking probability corresponding to the particles A method of generating a crosslinked particle model for molecular dynamics calculation, comprising: performing a process.   The method according to claim 4, wherein a reaction treatment between the preferential crosslinking particles and the crosslinking agent particles is performed, and thereafter, a reaction treatment between all the particles constituting the polymer particle model and the crosslinking agent particles is performed.   The method according to claim 4 or 5, wherein particles are randomly selected from all particles constituting the polymer particle model, and at least three consecutive particles including the selected particles are set as the preferentially crosslinked particles. Computer program for executing the method according to the computer in any one of claims 4-6.