Simulation method for high polymer material

Patent metadata

Field	Value
Publication number	US-9477794-B2
Application number	US-201313859035-A
Country	US
Kind code	B2
Filing date	Apr 9, 2013
Priority date	May 16, 2012
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A computerized simulation method for evaluating the dispersion of fillers in a high polymer material is disclosed. The method comprises: a simulation step in which, using filler models and polymer models placed in a predetermined virtual space, a molecular dynamics calculation is performed; and an evaluation step in which, from results of the simulation step, the dispersion of the filler models is evaluated. The evaluation step includes a step of computing a mean-square displacement of most influential particles for which a cutoff distance largest in the filler particle is defined. Thereby, the dispersion can be evaluated certainly at short times.

First claim

The invention claimed is:

1. A computerized simulation method for evaluating the dispersion of fillers in a high polymer material comprising:
defining filler models of the fillers, wherein each of the filler models represents a plurality of filler particles which are a single most influential particle and at least four surface particles of which centers are positioned on a spherical surface whose center coincides with a center of said single most influential particle;
defining polymer models of the high polymer material, wherein each of the polymer models represents one or more polymer particles;
defining potentials between particles which are the filler particles and the polymer particles, wherein
each potential is a function of a distance between the centers of the particles, and defined as causing a mutual interaction between the particles when the distance is decreased under a predefined cutoff distance,
a largest cutoff distance is defined for the single most influential particle, and
a cutoff distance smaller than said largest cutoff distance is defined for each of the surface particles;

defining an equilibrium length between the single most influential particle and each of the surface particles in each of the filler models;
defining an equilibrium length between the surface particles in each of the filler models;
performing a molecular dynamics calculation for the polymer models and the filler models placed in a predetermined virtual space; and
evaluating a state of dispersion of the filler models from results obtained through the molecular dynamics calculation, wherein
a mean-square displacement of each of the filler models is obtained by computing a mean-square displacement of the single most influential particle without computing a mean-square displacement of each of the surface particles, and
the state of dispersion of the filler models is evaluated based on the obtained mean-square displacements of the filler models,

wherein a cutoff distance between the single most influential particles of two of the filler models is larger than the sum of the radius of the above-mentioned spherical surface and a cutoff distance between the surface particles of the two of the filler models,
wherein the defining the potentials between particles includes:
defining the largest cutoff distance between the most influential particle of a filler model and the most influential particle of another filler model;
defining a smallest cutoff distance between any particle other than the most influential particle of a filler model and any particle other than the most influential particle of another filler model; and
defining a middle cutoff distance between the most influential particle of a filler model and any particle other than the most influential particle of another filler model.

2. The simulation method according to claim 1 , wherein
the mean-square displacement is computed at five or more time intervals.

3. The simulation method according to claim 1 , wherein the function defining the potential between the particles is given by
U=a ij (1− r ij /r c ) 2 /2

wherein
U is the potential,
a ij is an invariable corresponding to the strength of the potential U,
r ij is the distance between the centers of the particles, and
r c is the cutoff distance between the particles.

4. The simulation method according to claim 3 , wherein the evaluating the state of dispersion includes obtaining a self-diffusion coefficient of the most influential particles.

Assignees

• Sumitomo Rubber Ind

Inventors

• Ueno Shinichi

Classifications

• G01N33/445

  Rubber · CPC title

• G06F30/20

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title

• C08L2666/02

  Organic macromolecular compounds, natural resins, waxes or and bituminous materials · CPC title

• G06F30/15

  Vehicle, aircraft or watercraft design · CPC title

• C08L21/00

  Compositions of unspecified rubbers · CPC title