磁流变液在外加磁场控制下流变行为的变化迅速且可逆，因而在机械电子系统中应用广泛。磁流变悬架的性能与磁流变液本构行为、减振器设计与控制算法均高度相关，且各变量之间深度耦合。针对现阶段材料结构控制一体化综合研究方法缺失导致的产品开发周期长和成本高等问题，本文基于产品开发流程从磁流变液关键本构建模、测试与应用优化三个方面开展系统研究。在建模方面，聚焦磁流变液多物理场流变本构关系，提出指数线性混合解析（Exponential Linear Mixed Analytical，ELMA）模型并引入Doolittle方程，解决了宽剪切速率和温度范围内非线性流变行为难以精确描述的问题。通过改进Mason数建立了描述磁流变行为的高精度ELMA多变量模型，并基于自由体积理论建立了黏度-温度-压强本构关系。建立了单筒磁流变减振器机-电-液-气-磁耦合物理模型以研究其动态响应。结合基于ELMA模型的流变参数辨识方法，实现了单筒磁流变减振器动态特性的精确预测（平均误差小于142 N）。在测试方面，聚焦磁流变液流变行为表征，开发了非牛顿流体精确流变测试方法，以降低由牛顿流体假设和壁面滑移等因素导致的测试误差。提出了基于片状压头的沉降磁流变液流变行为微损测试方法，并以此实现了悬浮液再分散性解耦表征与表面活性剂快速筛选，揭示出表面活性剂与触变剂对再分散性的影响机理。在优化方面，明确了磁流变液沉降、流变和老化行为机理，归纳了磁流变液组分的性能相关性。引入油溶性石墨烯以解决传统抗磨减阻剂影响触变剂网络和使用损耗的问题，并改善了磁流变液的摩擦学和流变学性能。明确了磁流变液的工作模式定义，并提出了改进剪切模式的两种新减阻工作原理，可使磁流变减振器的最小阻尼降低约10%。基于车辆动力学分析以及对传统启发式半主动悬架控制算法的能量流分析，提出了反用地棚和天棚的悬架控制算法，并分别改善了乘坐舒适性和车轮接地性。具体地，相较于天棚算法，反地棚算法使乘坐舒适性提升约27%。综上，本文实现了由磁流变液流变数据到减振器动态特性的端到端建模，为材料结构一体化研究奠定了基础。明确了磁流变液沉降、流变和老化行为机理，提出了再分散性的量化测试方法与反用地棚和天棚的悬架控制算法，为磁流变液的工程应用提供了理论和技术支撑。
Magnetorheological fluids (MRFs) have a wide range of applications in mechatronic systems due to their ability to rapidly and reversibly change their rheological behavior in response to an applied magnetic field. The performance of magnetorheological suspension systems depends on the constitutive behavior of MRFs, as well as the design and control algorithms of magnetorheological dampers (MRDs), and the variables are deeply coupled. The absence of a material-structure-control integrated comprehensive research methodology at this stage has resulted in protracted product development cycles and high costs. In view of this, this thesis conducts systematic research based on the product development process from three aspects, namely, key constitutive modeling, testing, and application optimization of MRFs.In terms of modeling, the focus is on the multi-physics rheological constitutive relation of MRFs. To address the challenge of accurately describing the nonlinear rheological behaviors of MRFs over a wide range of shear rates and temperatures, the thesis proposes the exponential linear mixed analytical (ELMA) model and introduces the Doolittle equation. A high-precision ELMA multivariate model describing the magnetorheological behavior is established using the modified Mason number, and the viscosity-temperature-pressure constitutive relation is established based on the free volume theory. Mechanical-electrical-liquid-air-magnetic coupled physical models of the monotube MRD are developed to study its dynamic responses. Moreover, the dynamic characteristics of a monotube MRD are accurately predicted (with an average error of less than 142 N) by incorporating a rheological parameter identification method based on the ELMA model.In terms of testing, the focus is on the characterization of the rheological behavior of MRFs. Accurate rheological measurements of non-Newtonian fluids are developed to reduce the testing errors caused by factors such as the Newtonian fluid assumption and wall slip. A micro-destructive method for measuring the rheological behavior of settled MRFs using a sheet indenter is proposed, which enables the decoupled characterization of suspension redispersibility and the rapid screening of surfactants, and reveals the influence mechanisms of surfactants and thixotropic agents on the redispersibility.In terms of optimization, the mechanisms of sedimentation, rheological behavior, and the aging process of MRFs are clarified, and the performance correlations of MRF components are summarized. The introduction of oil-soluble graphene solves the problem of conventional antiwear drag-reducing agents that typically disrupt the thixotropic agent network and degrade over time, and improves the tribological and rheological properties of MRFs. Furthermore, the MRF operation modes are clearly defined, alongside the proposal of two new drag-reducing operation modes that are realized by modifying the shear mode, which can reduce the minimum damping of MRDs by about 10%. In addition, based on vehicle dynamics analysis and the energy flow analysis of traditional heuristic semi-active suspension control algorithms, inverse ground-hook and inverse sky-hook suspension control algorithms are proposed, which achieve improvements in ride comfort and wheel ground adhesion, respectively. Specifically, compared to the sky-hook algorithm, the inverse ground-hook algorithm improves the ride comfort by about 27%.In conclusion, this thesis achieves end-to-end modeling from MRF rheological data to MRD dynamic characteristics, which lays the foundation for material-structure integrated research. The mechanisms of sedimentation, rheological behavior, and the aging process are clarified. A quantitative redispersibility test method and inverse ground-hook and inverse sky-hook suspension control algorithms are proposed. These contributions collectively provide essential theoretical and technological support for the engineering application of MRFs.
