Simulation Studies of Electrorheological Fluids under Shear, Compression, and Elongation Loading Simulation Studies of Electrorheological Fluids under Shear, Compression, and Elongation Loading

Mechanical properties of electrorheological uids under various dynamical loading conditions have been studied using a computer simulation model. The model assumes electrostatic point-dipole interaction between particles with or without multipolar corrections and the interaction with the base uid due to viscous laminar ow is described with Stokes drag. The mechanical loading is introduced as constant rate shear, compression or elongation to a system of particles set initially to a single chain, a column of body centered tetragonal (BCT) unit cells, a thick BCT-structure or to a structure grown with electric eld from originally random con guration. Results show that the relative strength of the single chain structure is usually largest. Electrorheological systems under compressive loading were found to transmit largest force from one plate to another. Under elongation loading a thick BCT-structure seemed surprisingly weak compared with the system under compression or shear. In addition, the response of a BCT-structure under sinusoidally alternating shear or tensile straining have been studied. It was found that under tensile loading the ability of the system to transfer force is dependent on oscillation frequency much more than under shear loading. 1