Properties and mechanical model of a stiffness tunable viscoelastic damper based on electrorheological elastomers

Conventional viscoelastic dampers based on common elastomers cannot adjust their stiffness to adapt to complex vibration conditions. To overcome this shortcoming, a novel stiffness tunable viscoelastic (STV) damper is proposed in this study. Electrorheological elastomers (EREs), which present a tunable storage modulus by applying electric fields, were used as the key materials to provide the STV damper with electric field responsive stiffness. A series of experiments was conducted to study the dynamic mechanical properties of the STV damper under different displacement amplitudes, frequencies, and electric field strengths. The results indicated that the force–displacement hysteretic curve of the STV damper depends on displacement amplitude and frequency, and could be actively controlled by the electric field strength. Consequently, the equivalent stiffness, equivalent damping, equivalent damping ratio, and energy dissipation capacity of the STV damper were electric field responsive terms. A mechanical model of the STV damper was established on the basis of the material constitutive. The simulation results obtained by the model agreed well with the experimental data, indicating that the model can be used for semi-active control of the STV dampers.