磁流变弹性体阻尼器-转子系统的移频特性研究

Study on the performance of frequency shifting of a MR elastomer damper-rotor system

磁流变弹性体中铁磁颗粒成分对磁流变弹性体阻尼器的刚度可控特性具有重要影响。研制了分别由大颗粒和小颗粒铁粉制备的多种不同质量分数的磁流变弹性体,采用一种挤压式磁流变弹性体阻尼器-柔性转子系统研究铁粉颗粒直径和质量分数对转子系统临界转速的影响。试验结果表明,含有大颗粒铁粉的弹性体阻尼器在小电流时就有明显的移频作用。在相同控制电流条件下,由小颗粒铁粉制备的弹性体阻尼器-转子系统,随铁粉质量分数的增加,系统的临界转速变化(移频特性)越明显;而由大颗粒铁粉制备的弹性体阻尼器-转子系统,其临界转速随铁粉质量分数的变化规律与小颗粒铁粉的刚好相反。

The ferromagnetic grains in magneto-rheological（MR） elastomers have important effect on the stiffness control properties of MR elastomer damper.In this paper,a series of MR elastomers with different mass fraction are prepared by using larger ferromagnetic grains and smaller ones.A squeeze mode MR elastomer damper-flexible rotor system is used to test the effect of the particle size and mass fraction on the characteristics of the first critical speeds of the rotor system.It is found from the test that even under small control current,the MR elastome damper containing larger ferromagnetic grains has obvious frequency-shifting effect.Under the same control current,for MR elastomer damper-rotor system with smaller ferromagnetic grains,as the mass fraction of ferromagnetic grains increases,the first critical rotational speed of the rotor system is increased obviously;but for the rotor system with larger ferromagnetic grains,the first critical rotational speed is changes oppositely with the mass fraction compared with the former one.