The Change of Volume and Shape of Particles Suspended in Electrorheological Fluids

Based on the dipolar approximation, the change of volume and shape of particles suspended in electrorheological fluids(ER) are investigated by using the electric polarization method. The relative variational rate is calculated for the volume and shape of particles. The results of computation show that the relative variationa rate of the volume and shape of particles is in direct proportion to the square of electric field intensity, and relates to the character of ER. The relative variational rate of the volume and shape of particles is 8.4% and 12.5%, and the contribution to integral volume is 1.68% under the general condition. The contribution is devised by the change for electrodilatancy and electric heating of ER. The free energy is in direct proportion to the square of electric field intensity when particles are imagined as rigid balls.