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In general, shear thickening fluids show a marked increase in viscosity beyond a critical shear rate, which can be attributed to the hydrodynamic clustering effects, where in any external energy acting on a shear thickening fluid is dissipated quickly. However, there is a lack of theoretical modeling to predict the viscosity curve of shear thickening fluids, which changes continuously with the increasing shear rate. In this article, a phenomenological continuous viscosity modeling for a class of shear thickening fluids is proposed. The modeling predicts shear thickening and thinning behaviors that are naturally exhibited by shear thickening fluids for high and high enough values of the shear rate. The result shows that the phenomenological modeling provides a very good fit for several independent experimental data sets. Therefore, the proposed modeling can be used in numerical simulations and theoretical analysis across different engineering fields.

The forced vibration of a sandwich beam integrating a shear thickening fluid (STF) core and with conductive skins subjected to a periodic excitation was investigated theoretically in this study. The rheological properties of the STF material including viscosity, plasticity, and elasticity may be changed under the periodic vibration, and hence they were considered. The governing equation of motion was derived based on the complex stiffness method and some key parameters were derived based on the Timoshenko beam theory. Effects of the excitation frequency, the excitation amplitude, the excitation location, and the skin/core thickness ratio on the nature frequency of the sandwich beam were investigated. It was found that the STF core has a significant effect on the dynamic property of the sandwich beam. Based on the findings, integrating the STF core in a sandwich beam can reduce the vibration of the beam.

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Summary 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.