剪切增稠行为的微观机理实验研究

Dense suspensions exhibit shear thickening behavior under external loading, accompanied by a large amount of energy dissipation, so they have broad application prospects in impact resistance and other fields. This project intends to carry out experimental research on the micro-mechanism of shear thickening behavior, carry out macro-rheological tests under various loading conditions, and analyze the relationship between macro-rheological behavior and internal micro-structure evolution of materials by means of micro-observation with in-situ mechanical loading device mounted on electron microscope. In view of the controversy over the understanding of the micro-mechanism of shear thickening, this project intends to study the type and magnitude of interaction forces between particles and dispersing media, and to design and carry out microscale loading experiments. It is expected to realize theoretical understanding and experimental confirmation of the micro-mechanism of shear thickening behavior. Finally, it will provide theoretical guidance and experimental support for the establishment of shear thickening model and its application in the field of impact resistance.

浓稠微纳米颗粒悬浮液在外加载荷作用下呈现剪切增稠行为并伴随大量能量耗散，因此在抗冲击等领域具有广阔的应用前景。本项目拟针对剪切增稠行为的微观机理开展实验研究，实施多种加载条件下的宏观流变测试，采用电子显微镜搭载原位力学加载装置的微观观测手段，分析材料的宏观流变行为与内在微观结构演化的关系。鉴于目前对剪切增稠行为的微观机理认识尚存争议，本项目通过研究颗粒间、颗粒与分散介质间作用力类型和大小，设计开展微纳尺度加载实验，预期实现对剪切增稠行为微观机理的理论认识和实验确认。最终为剪切增稠模型的建立以及在抗冲防护等领域的应用提供理论指导和实验支撑。

浓稠微纳米颗粒悬浮液在外加载荷作用下呈现剪切增稠行为并伴随大量能量耗散，因此在抗冲击等领域具有广阔的应用前景。本项目针对剪切增稠行为的微观机理不明确的问题开展实验研究，实施多种加载条件下的宏观流变测试，结合颗粒间、颗粒与分散介质间的作用关系研究成果，设计微纳尺度加载实验，分析材料的宏观流变行为与内在微观结构演化关系，探索剪切增稠行为的内在机理。研究初步明确了剪切增稠行为在微观上是分散相与分散介质间的流体润滑作用以及分散相间摩擦接触共同作用的结果。颗粒接触后，体系发生从流体润滑主导到摩擦接触主导的转变。研究对实现控制剪切增稠行为并将其剪切增稠液智能材料设计应用到合适的领域，起到支持作用。