SIMULTANEOUS MEASUREMENT OF VISCOELASTICITY AND ELECTRICAL-CONDUCTIVITY OF AN ELECTRORHEOLOGICAL FLUID

Simultaneous measurements of viscoelasticity and electrical conductivi ty are performed to study the dynamic characteristics of structures fo rmed in a highly concentrated electrorheological suspension under a de electric field of 1.8 kV/mm. Small amplitude oscillatory shear measur ements reveal that there is no direct correlation between the elastic modulus and the electrical conductivity of the suspension. A significa nt increase in conductivity is observed following large amplitude osci llatory shear and, in this case, the linear elastic modulus is also su bstantially enhanced. These observations are interpreted according to the concept of contact disorder arising from the anisotropic shape of the particulate phase.