剪切增稠液体的缓冲机理和力学性能

Investigation of shear thickening fluid on buffer mechanism and mechanical properties

剪切增稠液体(STF)是一种将纳米或微米级的颗粒分散到牛顿流体中而形成的非均质颗粒悬浮液。当冲击发生时,其表观黏度发生大幅度增大而变黏稠。冲击结束后,体系表观黏度降低,重新转变为液体。通过颗粒拥堵模型,解释了剪切增稠液体在冲击过程中的耗能机理,同时计算了冲击杆在冲击过程中的加速度响应。采用低速冲击试验,测试了其抗冲击特性,与传统吸能材料AV-200进行了吸能对比;结果表明:颗粒拥堵模型合理解释了低速冲击试验中出现的局部硬化现象,规避了传统方法中边界对剪切增稠液体的影响问题。剪切增稠液体具有优异的缓冲特性。理论分析结果与试验结果的良好吻合验证了理论方法的有效性。该研究为剪切增稠液体在缓冲领域的应用提供了参考。

Shear thickening fluid(STF)is a heterogeneous suspension of nanometer or micrometer particles in a non-Newtonian fluid.Because the effective viscosity increases greatly,it changes from liquid-like to solid-like while bearing an impact load.When the load is removed?it returns back to liquid-like state.A mechanical model based on particle jammed model is put forward by studying the role of added mass in the transition of the flow state.The acceleration response is also obtained from this method.Low speed impact test is used to study impact properties and compare with traditional energy absorbing material AV-200.The results show that the particle jamming model explains the local hardening phenomenon reasonably in low speed impact test and avoids the influence of boundary on shear thickening fluid in the traditional method.The shear thickening fluid possesses excellent cushioning properties.By comparing the acceleration response of impact rod from theoretical analysis with those from the experimental work,it is found that the approach proposed in this work is effective.This study lay a foundation for cushioning material by using shear thickening fluid.