Experimental investigation on hysteretic behavior of a shear thickening fluid damper

In this study, a shear thickening fluid (STF) damper was experimented upon under different loading frequencies and amplitudes to investigate its nonlinear hysteretic behavior and energy dissipation capacity. An STF sample with 20% mass fraction and dispersion medium were prepared by nanoparticle silica (SiO2) and polyethylene glycol (PEG200). By using a parallel-plate rheometer, steady-state experiments were carried out to characterize the rheological properties of the sample. The results indicate that the STF sample shows an abrupt increase in viscosity/stress beyond a critical shear rate/strain. The results also show that the STF sample has good reversibility, thixotropy, and stability and can be used as a smart damping material in damper devices. Also, a prototype damper was developed and manufactured. Its nonlinear hysteretic behavior and energy dissipation capacity were experimentally investigated through the responses of damping force–displacement and damping force–velocity. The results show that the STF damper has excellent damping force as the loading condition increases and the controllability can be increased up to 3.21 times. The results also show that the energy dissipation capacity formed by damping force–displacement becomes fuller as the loading condition increases. Moreover, the results show that the graphical shapes of hysteretic loops of damping force–velocity can exhibit various styles as the STF's mechanism changes but the shapes are not stable when the velocity exceeds a certain value.