To predict the shear stress of magnetorheological fluids (MRFs) under magnetic field and shear flows, a meso-microscale shear model is proposed based on the entire course of particle aggregates and chains. For this purpose, a systematic study on the microstructure evolution and rheological properties of MRFs is conducted by using molecular dynamics simulations. An efficient chain identification technique is introduced to count the number of particle chains within the suspension system. From the perspective of particle-level simulations, the microstructured behavior of MRFs involving particle aggregation and internal structure evolution of magnetorheological suspensions are addressed. Shear properties of MRFs derived by the proposed model are studied, and model verification by comparison with previous experimental data and predictions of the existing structural viscosity model is included as well. It is revealed that the proposed meso-microscale shear model exhibits satisfactory accuracy and efficiency for describing the rheological properties of MRFs. Besides, the critical factors linked with rheological properties of MRFs such as magnetic field strength, particle volume fraction and shear rate, are analyzed, further demonstrating the applicability of the proposed model in design and optimization of MRFs.

中文翻译：

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基于微观结构演化的磁流变流体剪切屈服应力粒子链模型

为了预测磁场和剪切流下磁流变流体 (MRF) 的剪切应力，提出了一种基于颗粒聚集体和链的整个过程的中微尺度剪切模型。为此，通过使用分子动力学模拟对 MRF 的微观结构演变和流变特性进行了系统研究。引入了一种有效的链识别技术来计算悬浮系统内的颗粒链数量。从粒子级模拟的角度，涉及磁流变悬浮液的粒子聚集和内部结构演变的 MRF 的微结构行为得到解决。研究了由所提出的模型导出的 MRF 的剪切特性，还包括通过与以前的实验数据和现有结构粘度模型的预测进行比较的模型验证。结果表明，所提出的中微尺度剪切模型在描述 MRF 的流变特性方面表现出令人满意的准确性和效率。此外，分析了与 MRF 流变特性相关的关键因素，如磁场强度、颗粒体积分数和剪切速率，进一步证明了所提出的模型在 MRF 设计和优化中的适用性。