Shear strength of electrorheological particle clusters

The electrorheological shear strength of clusters of small, humidified glass spheres with an average diameter ∼220 μm in silicone oil forming a rectangular or cubic lattice was determined with d.c. electrical field. The arrangement, shearing, and the yield and fracture processes of the clusters were observed. The shear strength of the cluster increased with the number of chains in a cluster and with the applied electrical field. The shear modulus was essentially independent of the number of chains in a cluster, but increased with applied field.