Sumitomo Heavy Industries, Ltd.

Daiji Ichishima

Shuji Miyazaki

Yoshitaka Ohnishi

Yoshitaka Kobayashi

Ryouta Hirose

A simulation method includes: a process of performing a renormalization transformation process with respect to a granular system S that is a simulation target that includes a plurality of polymers that are respectively formed of a plurality of monomer grains that are connected to each other in one dimension, on the basis of a renormalization factor &#x3bb; depending on the number of times of renormalization; and a process of calculating a position vector and a momentum vector of a monomer grain in a renormalized granular system S' by executing molecular dynamics calculation with respect to the renormalized granular system S&#x2032;.

Simulation method, simulation program, and simulation device

In simulating a behavior of a particle system including a plurality of particles disposed in an analysis region, by using a molecular dynamics method, centroid velocities of the particles present in a local region including a particle of interest are converted on the basis of the number of particles present in the local region for each of the particles, and thus a conversion value of a centroid velocity of the local region is calculated. Temperature control of maintaining the temperature of the particle system to be a target temperature is performed by using a difference between a velocity of the particle and the conversion value of the centroid velocity of the local region including the particle as a velocity of the particle which is a basis for calculating the temperature of the particle system.

Simulation method, simulation apparatus, and program

An analyzer includes a magnetic moment application unit configured to apply a magnetic moment to a particle system defined in a virtual space, a magnetic field calculation unit configured to calculate a magnetic physical quantity related to the particle system including particles, to which the magnetic moment is applied by the magnetic moment application unit, and a particle state calculation unit configured to numerically calculate a governing equation, which governs the movement of each particle, using the calculation result in the magnetic field calculation unit. The magnetic field calculation unit numerically calculates an induction magnetic field using induced magnetization induced in each particle due to a time variation in an external magnetic field and a magnetic field obtained by interaction between magnetic moments based on the induced magnetization.

Analyzer

A coupled simulation of a structural-elastic phenomenon and a heat conduction phenomenon of a simulation target including plural particles is performed. Here, numerical calculation of a motion equation capable of being transformed into an equation of the same form as that of a heat conduction equation is performed with respect to a term of a spatial temperature distribution and a term of a derivative of temperature with respect to time, to perform a simulation of the heat conduction phenomenon of the simulation target.

Simulation method, simulation apparatus, and simulation program

A granular material is a simulation target, wherein a force acting on each grain is expressed by a potential dependent term and an energy dissipation term. The potential dependent term depends on an interaction potential &#x3d5; between the grains. Physical quantities included in the potential dependent term are renormalization-transformed so that a hamiltonian form expressed by a kinetic energy of the each grain and a potential energy based on the interaction potential &#x3d5; does not change. Physical quantities included in the dissipation term are renormalization-transformed so that a change rate of the potential dependent term and a change rate of the dissipation term become equal. Temporal development of a renormalized granular material is calculated by performing numerical integration with respect to a motion equation of each grain of the renormalized granular material.

Simulation method of granular material and simulation device thereof

An analyzer comprises a particle system acquisition unit operative to acquire information on a particle system defined in a virtual space; a magnetic moment association unit operative to associate a particle in the particle system with a magnetic moment; a numerical operation unit operative to perform numerical operation according to a governing equation that governs a motion of each particle in the particle system, the particle system including the particle which is associated with the magnetic moment by the magnetic moment association unit; and a magnetic field calculation unit operative to calculate a magnetic field created by the particle system using the results of the numerical operation performed by the numerical operation unit.

(a) Regarding a particle system S in which the number of particles is N, the mass of each particle is m, and inter-particle interaction potential energy can be expressed by &#x3b5;f, &#x3b1; greater than 1, &#x3b3; equal to or greater than 0 and equal to or smaller than d, and &#x3b4; equal to or greater than 0 are determined using a dimension number d of a space where the particle system S is arranged to obtain the number N' of renormalized particles by N&#x2032;=N/&#x3b1;, to obtain the mass m&#x2032; of each of the renormalized particles by m&#x2032;=m&#x3b1;/&#x3b1;, and to obtain a renormalized interaction coefficient &#x3b5;&#x2032; by &#x3b5;&#x2032;=&#x3b5;&#x3b1;. (b) Molecular dynamics calculation is carried out on a particle system S&#x2032; in which the number of renormalized particles is N&#x2032;, the mass of each particle is the mass m&#x2032; of each renormalized particle, and inter-particle interaction potential energy is expressed by &#x3b5;&#x2032;f.

Simulation method

A molecular simulation method that acquires physical properties or physical quantities of a predetermined shape using simulation, including arranging atoms in the predetermined shape, acquiring interatomic potential based on positions of the arranged atoms, and carrying out a molecular dynamics calculation based on the acquired interatomic potential, and acquiring the physical properties or the physical quantities.

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Kanagawa, Japan

Daiji Ichishima