Dynamic behavior of shear-thickening fluids under harmonic excitation: an experimental investigation

TL;DR

This experimental study investigates how shear-thickening fluids respond dynamically to harmonic forces, revealing their damping effects and behavior across different resonance regions, which can inform engineering design.

Contribution

First experimental analysis of STF behavior under harmonic excitation, identifying distinct dynamic regions and damping effects not previously characterized.

Findings

STFs reduce resonance amplitudes effectively

Three dynamic behavior regions identified: pre-resonance, resonance, post-resonance

STF force acts as damping at resonance

Abstract

Shear-thickening fluids (STFs) become more viscous under shear stress, which makes them useful for many engineering and scientific applications. However, their behavior under normal forces, especially when these forces are applied harmonically, is less understood. Here, we examine the dynamic response of STFs under harmonic excitation. Our experimental setup features an unbalanced rotor attached to a vibrating plate submerged in an STF-filled container. We monitored the rotor's speed, the system's displacement, and the STF force. Data from experiments without STF were used to identify system parameters, and measurements of the STF force revealed the dynamic nature of the STF force. By comparing responses with and without STF, we identified three regions of behavior: in the pre-resonance region, the STF force is negligible; at resonance, it acts as a significant damping force; and in the post-resonance region, it behaves like an on-off force. Overall, the STF effectively reduces resonance amplitudes. These results can inform the design of complex structures incorporating STFs.