Design and vibration damping study of a novel variable stiffness composite based on electrorheological fluid

We propose a novel variable stiffness composite (VSERF) made of soft materials, featuring a three-layer fluid-membrane composite structure with electrorheological fluid encapsulated in a thin film. The overall shear storage modulus of this composite can be described using a viscoelastic model. Under a 3 kV/mm electric field, the electrorheological fluid transitions from a liquid to a quasi-solid state, resulting in a 25-fold increase in the overall shear storage modulus of the VSERF, allowing for controllable changes in stiffness. We used VSERF as a variable stiffness element in a vibration absorber. When the electric field strength was increased from 0 to 3 kV/mm, the natural frequency of the absorber shifted from 13 to 21 Hz, indicating that vibrations within this range of excitation frequencies could be effectively controlled. The damping ratio of the VSERF absorber is below 0.189, and its transmissibility peak exceeds 2.9, ensuring that the absorber can effectively transmit vibrations from the excitation source to the mass, enhancing vibration damping. Consequently, VSERF shows promising potential for energy absorption and vibration damping applications.