磁流变智能镗杆的动态特性测试与分析

为了给磁流变智能镗杆制定有效的颤振控制策略,对其动态特性进行了测试与分析.通过瞬态激振方法对智能镗杆的刚度与阻尼特性关于磁场强度大小的变化规律进行了研究,结果显示其刚度特性随磁场强度的增加而单调增加,阻尼变化则为先增后减；采用稳态激振法对智能镗杆的动态特性与外界激振频率、幅值和磁场强度之间的关系进行了研究,结果表明,在以磁流变材料屈服前系统共振频率为中心的频段内,系统会出现强非线性现象,且磁场强度越高,非线性频段就越窄.

Measurement and analysis of dynamic characteristics of magnetorheological intelligent boring bar

The dynamic characteristics of magnetorheological (MR) intelligent boring bar were investigated to establish the efficient control strategy for cutting chatter suppression. The variable laws of the MR intelligent boring bar's stiffness and damping were investigated by adjusting the magnetic intensity based on transient exciting method. Results showed that the stiffness of MR intelligent boring bar monotonously increased with increasing the magnetic intensity, while the damping increased firstly and then decreased. The MR intelligent boring bar was tested by steady state exciting method. Results showed that the system dynamic characteristics were influenced by vibration amplitude, frequency and magnetic intensity. The system performed strongly nonlinear phenomenon when the vibration frequency falled into a certain band centered around the natural frequency of pre-yield system. The stronger the magnetic intensity was, the narrower the nonlinear frequency band was.