In order to test the dynamic mechanical propertyof silicon rubber materials using split Hopkinson pressure bar

theeffects of the thickness of pulse shaper on thecharacteristics of incident stress wave were experimentally examined. Based on the analysis on the stress and strainuniformity in the soft viscoelastic specimens

the proper thickness of pulse shaper was determined. The experiment tests and numerical simulations were carried out to analyze the effects of specimen size on the deformation characteristics and dynamic mechanical properties of silicon rubber. The results showed that for the specimens with thickness higher than 3mm

it is hard to achieve the equilibrium state of contact pressures on the two ends of the specimen to the pressure bars. The nonuniform deformation of specimen can cause the stress plateau and even stress softening in the tested stress-strain curves at high strain rate deformation. The dynamical mechanical properties of the soft silicon rubber at different strain rate deformation were tested. A hyper-viscoelastic constitutive modelconsisting of hyperelasitic and viscoelastic constitutive equationswas used to describe the dynamic mechanical behavior of the rubbermaterial. A new parameter fitting method was put forward for the viscoelastic parameter calculation of the viscoelastic model

and they could be conveniently calculated by the proposed method.