材料期刊网

Rayleigh identity based on a multipole expansion theory is extended to analyze the forces between particles in electrorheological system. The shear modulus for chains of particles arrayed on a square lattice is calculated. It is found that the modulus increases linearly with the ratio of dielectric constants of dispersed particles to the continuous phase, as the ratio becomes large, contrary to expectations from a simple dipole approximation where it would saturate. In the case of conducting particle, the modulus varies with the frequency of applied held. A limiting case of infinitely conducting particles conductivity is considered. It is found that the particle-particle forces are extremely sensitive to their separation. (C) 2001 Elsevier Science B.V. All rights reserved.