A novel investigation of shear thickening fluids under continuous high-frequency impact

Shear thickening fluid (STF) has unique rheological characteristics, for its viscosity is dependent on the variation in strain rate under specific shear conditions. STF can significantly reduce shocks and vibrations by absorbing a large amount of impact energy during external loads. The dynamic impact characteristics of STFs under high-frequency impact loads are examined in this work. We measured the changes in the energy storage modulus and energy dissipation modulus with angular frequency by performing dynamic rheological tests on STFs. We constructed a high-frequency dynamic continuous impact experiment platform for STFs. It is possible to quantify changes in acceleration and impact force for STFs at varied impact frequencies by this platform. Analysis was done on the changing law of STFs’ high-frequency impact characteristics. The results indicated that an increase in the fraction of STF leads to a decrease in the critical angular frequency, accompanied by a pronounced viscosity of the STF. The critical angular frequency was determined as 0.255 rad/s for silica-polyethylene glycol (SiO 2 -PEG) STF at a fraction of 23% and 0.349 rad/s for cornstarch-water STF at a fraction of 60%. Under continuous dynamic impact, cornstarch water STFs have a notable thickening effect, while SiO 2 -PEG STFs can absorb more impact energy.