三磁铁磁性动力吸振器的宽频减振研究

Research on Broad Band Vibration Reduction of a Triple-magnet Magnetic Dynamic Vibration Absorber

提出一种可实现宽频减振的新型三磁铁磁性动力吸振器(TMDVA),该吸振器仅由三块圆柱形永磁铁和一个减振管组成。分析了该吸振器的非线性磁力特征,阐述了磁铁间距对磁力刚度的影响规律。以理想悬臂梁为减振对象建立了磁性吸振器-悬臂梁减振系统动力学模型,从瞬态动力学和能量角度揭示了吸振器对共振频率不同梁的宽频减振机制。研究表明,该吸振器可以有效实现宽频减振,调节磁铁间距可以优化吸振器的宽频减振效果。对于共振频率不同的梁,吸振器最优减振效果对应的磁铁间距与梁共振频率近似呈现线性关系,这为该吸振器的设计优化提供了便利。

A novel Triple-magnet Magnetic Dynamic Vibration Absorber(TMDVA)which can achieve broad band vibration reduction is proposed,which only consists of triple cylindrical permanent magnets and an acrylic tube.The magnetic force model is established,and the force characteristics are analyzed.The influence of magnet distance on the nonlinear magnetic stiffness is explained.Next,an equivalent dynamics model of the TMDVA cantilever vibration reduction system is established with an linear cantilever as the vibration reduction object.From the perspective of transient dynamics and energy,the broadband vibration reduction mechanism of the absorber on cantilevers with different resonance frequencies is revealed.The research results indicate that the TMDVA can effectively achieve broadband vibration reduction,and adjusting the magnet distance can optimize the vibration reduction effect of the absorber.For cantilevers with different resonance frequencies,when the vibration reduction effect of the TMDVA is optimal,the relationship between the magnet distance and the resonance frequency is approximately linear,which provides convenience for the design optimization of the TMDVA.