Dynamic mechanical properties of a novel rotary variable damper based on GCP/SiO ₂ -STF viscous fluid

A novel rotary viscous damper (RVD) with adjustable damping is proposed by combining a blade integrated rotor and a ball screw in this work. And the damping medium of this novel damper is based on graphene oxide, carbon nanotubes and polyvinylpyrrolidone modified silica-based shear thickening fluid (GCP/SiO ₂ -STF). STF-RVD can change the working state of the STF and expand its damping force output range by adjusting the lead and the angular velocity of the rotor, thereby achieving active control of the vibration energy dissipation efficiency. This work explores the influence of frequency, displacement, STF types, damper structural forms, and leads on the nonlinear mechanical behavior of GCP/SiO ₂ -STF-RVD. Research results demonstrate that, in comparison with the SiO ₂ -STF-RVD, the damping force of the GCP/SiO ₂ -STF-RVD is remarkably enhanced and no “collapse” phenomenon is observed in the hysteresis curves. Compared with the linear structural form, the energy dissipation of GCP/SiO ₂ -STF-RVD increased by 1297.97%–2082.47%. More importantly, by changing the lead parameters of the ball screw, the damping force generated by the damper can vary within the range of 0.63 to 3.14 times its reference value. Moreover, the double Sigmoid model can precisely depict the nonlinear mechanical behavior of the GCP/SiO ₂ -STF-RVD.