石墨烯对剪切增稠液挤压流动力学性能的影响

含有剪切增稠液的振动控制装置在服役阶段涉及挤压过程,研究剪切增稠液的挤压力学性能有着重要的意义.采用石墨烯增强纯二氧化硅纳米颗粒剪切增稠液,并利用旋转流变仪开展了挤压流动实验,测试了不同剪切增稠液的流变性能和挤压流动力学性能,得到了黏度曲线以及不同挤压速度下法向应力和临界间隙的变化规律,分析了石墨烯对剪切增稠液流变性能...

Study on the influence of graphene on the squeeze flow mechanical properties of shear thickening fluid

Vibration control devices containing shear thickening fluids (STFs) are involved in squeezing processes during service period. Therefore, the study on squeeze mechanical properties of STFs is of great significances. Graphene were adopted to reinforce the pure SiO₂ nanoparticle-based STF. The squeeze flow experiment was conducted by a rotary rheometer. The rheological properties and squeeze flow mechanical properties of different STFs were tested. The correlation between normal stress and critical gap under different squeeze speeds as well as the viscosity curve was obtained. The effects of graphene on the rheological properties and squeeze flow mechanical properties of STF were analyzed. The results showed that the graphene reinforced STF showed a significant increase in both viscosity and shear thickening efficiency. At the shear thickening stage, the maximum viscosity of the reinforced STF was 599.42 Pa·s, 74% higher than that of the pure STF. At the same time, under different squeeze conditions, with increasing the graphene volume fraction, both the normal stress and critical gap of STF increased, and the bearing capacity of STF was enhanced. Moreover, based on the hydrodynamic lubrication theory, the mechanism on how graphene affects the squeeze flow mechanical properties of STF was also discussed in this paper. It is concluded that the increase in the normal stress and critical gap can be attributed to the fact that graphene can effectively prevent the flow of nanoparticles and the existence of fluid lubrication force between graphene and graphene, graphene and particles. The results obtained in this paper can shed more insights into the design of high-performance STF devices under squeezing mode.