【作者】 李强； 董光旭； 张希农； 罗亚军； 张亚红； 谢石林；

【Author】 Qiang LI;Guangxu DONG;Xinong ZHANG;Yajun LUO;Yahong ZHANG;Shilin XIE;State Key Laboratory for Strength and Vibration of Mechanical Structure,Xi’an Jiaotong University;

【机构】 机械结构强度与振动国家重点实验室西安交通大学；

【摘要】 为有效抑制共振并拓宽频带,本文提出一种新型动力吸振器。该动力吸振器由螺旋弹簧片及三个轴向磁体结构构成的非线性磁性弹簧构成。将设计的新型吸振器置于悬臂梁控制其一阶振动时,悬臂梁可等效为线性单自由度系统。利用平均法推导出系统在简谐激励下的稳态频响方程组及稳定性判定准则,进而对系统响应仿真及影响参数分析。仿真结果表明,适当的参数可有效抑制主系统宽频范围内振动,消除突跳等不稳定响应。为寻找最优吸振器参数,在分析鞍结分岔存在性以及非线性、阻尼等参数对其影响的基础上,提出一种新的参数优化方法用于对吸振器几何和结构参数的优化。结果表明,由提出的参数优化方法得到的吸振器参数,在消除不稳定响应同时,可使主系统振幅在大范围内获得有效抑制。更多还原

【Abstract】 To suppress the resonance and broaden the bandwidth of vibration, a newly non-linear dynamic absorber(NDVA) is proposed in this paper. The implementation of the NDVA is carried out by connecting a spiral flexure spring and the magnetic negative stiffness spring generated by the structure consisting of three annular permanent magnets in parallel. The cantilever can be equivalent to a linear simple-degree-of-freedom system when the NDVA attached to the cantilever beam is used for suppressing its first order vibration. The steady-state response under harmonic force and the stability criterion are attained based on the averaging method, and further the simulation of system response and the analysis on the effect of dimensionless parameters are implemented, indicating that the appropriate parameter optimization of the NDVA can effectively suppress the vibration of primary system as well as eliminate instabilities such as jumps. For the sake of seeking the best parameters, based on the analysis of the existence of saddle-node bifurcation and on which the effect of the parameters, for example nonlinearity, damping, is carried out, an absolutely new method of parameter design is developed to the geometrical and structural optimization for the NDVA. The result shows that the parameters of the NDVA attained by the proposed method can realize the striking suppression for the amplitude of primary system as well as the elimination of instabilities in a broadband.更多还原