MR阻尼器动态特性的物理机制、能量转化及设计理论

In-depth understanding of the dynamic behavior of MR dampers is the key to applying the MR technology to the semi-active controls of structural vibration. The parametric or non-parametric models in existing studies, whose parameters are determined by fitting experimental data, are essentially belong to phenomenological models, although they show great accuracy in predicting the dynamic damping force, thus leading to outstanding vibration control effects. So far, the physical mechanism behind the dynamic behavior of MR dampers is still unknown, the energy conversion during the working process is studied in quality and the design method remains to be developed. This research proposal aims to solve these three problems in a gradual way based on the physical models of MR dampers. The mechanics- magnetics-heat coupling model will be developed to accurately calculate dynamic force, temperature, and energies of all kinds for dampers under arbitrary input electric currents and piston displacements. The physical mechanisms of both the generation of the force-velocity hysteresis and the effects of temperature on the damping force will be revealed. The rule and the dominant factor will be investigated for the impacts of structure parameters and way of the excitations on temperature distribution, dynamic damping forces and energy conversions. Moreover, the formula will be derived for calculating the hysteresis under sinusoidal displacement excitations, the response time under step displacement excitations, and the frequency of damping force under periodic excitations. The method will be proposed for designing and optimizing MR dampers based on the rule of energy conservation.

深刻理解MR阻尼器的动态特性是真正掌握MR减振技术的基础。现有研究通过拟合试验数据识别模型参数建立的参数化或非参数模型，虽在理论和实测上均获得了很好的控制效果，但其本质上是基于现象机制的唯象模型。目前，MR阻尼器动态特性的物理机制仍不清晰、内部能量转换缺乏定律研究、动态特性的设计理论仍未建立。本项目基于物理模型采用逐步深入的方式解决这三个基本问题。建立力-磁-热耦合的物理模型，以对任意电流和位移激励下的瞬态阻尼力、内部能量变化、温度分布进行准确的定量分析；揭示阻尼力-速度滞回形成的物理机制和温度影响阻尼力的物理机制；揭示结构参数和激励方式对温度分布、动态阻尼力、内部能量转换的影响规律和主要影响因素；推导正弦位移激励下速度-阻尼力滞回的设计公式；推导阶跃激励下阻尼器响应时间的计算公式；推导周期激励下阻尼力频率的计算公式；建立基于能量准则的MR阻尼器的设计和优化方法。