非线性能量阱刚度优化计算与振动台试验

发布时间：2018-01-01 05:04

本文关键词：非线性能量阱刚度优化计算与振动台试验　出处：《振动与冲击》2016年20期 　论文类型：期刊论文

【摘要】：介绍了一种通过几何非线性产生非线性回复力的NES,并对它的宽频控制特性进行了研究。首先通过解析方式求得1∶1共振下频率与能量之间的关系并绘制频率能量图,频率能量图直观的表达了当NES与线性振子连接到一起的时候,其相对于线性振子的振动频率与系统中能量水平有着直接关系。然后,在多自由度振动系统的模态空间中使用解析的方法将NES刚度与线性振子的能量、频率与振型建立起相关的表达式。由表达式得到振动系统在一定能量水平下,NES达到较优控制效果所需要的非线性刚度。根据较优刚度计算方法,设计了NES振动控制试验并进行振动台试验。为了试验NES宽频控制特性,振动台台面输入采用了针对频域测试的Chirp信号,试验过程中通过改变NES的弹簧刚度与增加被控框架质量来改变框架动力学特性的方法以检验NES宽频控制的效果。试验结果表明NES有较好的宽频控制效果,即使其刚度偏离优化值或被控对象动力学特性发生一定改变,NES依然能发挥较好的振动控制作用。
[Abstract]:In this paper, we introduce a kind of NES which can produce nonlinear recovery force by geometric nonlinearity. Firstly, the relationship between frequency and energy under 1: 1 resonance is obtained by analytical method, and the frequency energy diagram is drawn. The frequency energy diagram intuitively expresses that when the NES and the linear oscillator are connected together, the vibration frequency relative to the linear oscillator has a direct relationship with the energy level in the system. The NES stiffness and the energy of the linear oscillator are analyzed in the modal space of the multi-degree-of-freedom vibration system. The expression of frequency and vibration mode is established. The nonlinear stiffness of the vibration system is obtained for the NES to achieve a better control effect at a certain energy level. According to the calculation method of the optimal stiffness, the nonlinear stiffness of the vibration system is obtained. The NES vibration control test is designed and the shaking table test is carried out. In order to test the characteristics of NES wideband control, the Chirp signal of frequency domain test is used in the table input of the shaking table. In order to test the effect of NES wideband control, the method of changing the spring stiffness of NES and increasing the mass of controlled frame is used to test the effect of NES broadband control. The test results show that NES has better wideband control. Effect. Even if the stiffness deviates from the optimal value or the dynamic characteristics of the controlled object change to some extent, the NES can still play a better role in vibration control.
【作者单位】：同济大学机械与能源工程学院;同济大学土木工程防灾国家重点实验室;
【基金】：国家自然科学基金重大研究计划重点国际合作项目(51261120377);国家自然科学基金重大研究计划集成项目(91315301-4)
【分类号】：TB535
【正文快照】： 振动控制装置被广泛用于航天、汽车、机械与建筑工程中,目前大多数振动控制装置都是基于线性吸振器。随着对非线性振动研究的深入,非线性吸振器由于其宽频控制的特性引起了相关研究者们的广泛关注。ROBERSON等[1]最早提出了采用非线性振子作为吸振器进行振动控制,VAKAKIS等[2]

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