Constitutive Behaviors of a Silicone Rubber at High Strain Rates

Silicone rubber is a macromolecule polymer, and can suffer a large deformation. The silicone rubber specimens are tested at a series of strain rates by modified Split Hopkinson Pressure Bar (SHPB) techniques. Based on the experimental data, a constitutive model of the silicone rubber is built up based on Ogden strain energy functions. An interesting phenomenon－localized damage cycle, so called lag circle－shows up in the tested specimen under high strain-rates loading. The diameters of the damage cycle are associated with strain-rate and specimen's size. A formulation about the relations between the diameter and the strain-rate, specimen's size is presented.