US 2009/0024376 A1Published application

Computer program using particle method

OwnerAkio Hori, Hiromi Kojoinventors

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Abstract

Finite element methods are unsuitable for a dispersed system. Particle methods suitable for a dispersed system are limited in the particle shapes only a sphere that requires many particles to model a complicated shape especially in 3D. Proposed procedures for a particle method are roughly as follows. 1): Judging the existence of the contact between particles as that between mathematically-smooth closed surfaces representing particle shape and size. 2): Assuming an imaginary contact point and an imaginary contact plane the same as when both closed surfaces are reduced with the same scale to touch at one point. 3): Calculating imaginary contact area and imaginary contact stiffness etc. using the above point and plane. Based on these procedures, particle shapes are not limited but smooth. Therefore, a more complicated shaped problem in a dispersed system can be analyzed with less number of particles. Additionally, combined use with finite elements is capable.

Claims9

Dependent claims

Computer program to simulate physical or chemical phenomena with at least one non-spherical particle and occasionally with spherical particles and/or finite elements, and to calculate translational or rotational displacements of particles and/or element nodes, comprising the steps of:

(a) judging existence of contact between neighbor particles as existence of contact between mathematically-smooth closed surfaces representing each particle shape and size;
and the following (b) to (e) between two particles under the judged contact condition,
(b) assuming an imaginary contact point uniquely the same as when both the closed surfaces are reduced isotropically with the same scale to touch at one point;
(c) assuming an imaginary contact plane to contain the imaginary contact point and to have a same-directional perpendicular as both normal vectors on both reduced closed surfaces at the imaginary contact point;
(d) calculating imaginary contact area using the imaginary contact point and the imaginary contact plane;
(e) calculating characteristic values or matrices between both contact particles about stiffness, transmission resistance, transportation resistance or these inverse, using the imaginary contact point, the imaginary contact plane and the imaginary contact area;
and
(f) Based on the characteristic values or matrices between both particles, calculating the characteristic matrix between degrees of freedom of most of particles, solving the simultaneous usually-linear equations, and calculating translational or rotational displacements or displacement increments of the particles and occasionally of element nodes.

5 more elements

Dependencies are inferred from the claim text.