磁流变智能镗杆的动力学模型

为了准确地在线调控磁流变智能镗杆的动态特性,有效地进行颤振抑制,对动力学模型进行研究.根据磁流变材料在屈服前区、屈服区和屈服后区所表现出的动态特性,结合Kelvin和Maxwell模型,建立本构模型,分析结果表明:该模型能够较好地反映磁流变材料动态特性.在此基础上,建立磁流变智能镗杆的动力学模型,并对屈服前后的动态特性进行分析,同时推导智能镗杆中磁流变材料的屈服临界条件,分析结果揭示:屈服一般发生在以磁流变材料屈服前系统共振频率为中心的频段内,且磁场强度越高,屈服频段越窄.对磁流变智能镗杆动力学模型进行数值仿真研究,分析结果与实测数据对比后表明:该模型能够较准确地描述磁流变智能镗杆动力学特性.

Dynamic model of magnetorheological intelligent boring bar

To control the dynamic characteristics of magnetorheological (MR) intelligent boring bar precisely, its dynamic model needs to be investigated. Firstly, according to the dynamic characteristics of MR fluid in pre-yield region, yield region and post-yield region, the constitutive model of MR fluid was established on the basis of Kelvin model and Maxwell model, and the results of numerical analysis show that the model can describe the MR fluid‘s dynamic characteristics accurately. Then the dynamic model of MR intelligent boring bar was established based on the constitutive model of MR fluid, and its characteristics was analyzed in pre-yield region and post-yield region, respectively. And the yield critical condition of MR fluid in the intelligent boring bar was deduced, the results show that yield phenomenon always occurs in a certain frequency band centered around the natural frequency of pre-yield system, and the stronger the magnetic intensity is, the narrower the yield frequency band is. Lastly, the numerical simulations of the dynamic model were carried out, and the results show that the dynamic model can describe the MR intelligent boring bar’s dynamic characteristics accurately．