基于非线性能量吸振器的高耸结构减振分析

Vibration suppression analysis for a tall structure attached with a nonlinear energy sink absorber

非线性能量阱(NES)类型的振子具有宽频吸振的特性,可利用其对高耸结构进行减振。通过建立相应的偏微分运动方程,并利用伽辽金法及Rauscher方法,获得了非线性模态的解析解,揭示了NES振子的吸振原理。再通过非线性有限元分析,对该系统振动特性随NES振子各参数的变化进行了研究。研究结果表明:NES振子存在最优参数从而明显地抑制结构振动,最大可使结构振动减为原来的20%左右;所提出的经验公式可方便地计算NES振子立方非线性刚度系数的最优值,且与有限元计算结果吻合。

Nonlinear energy sink （NES）absorber has a critical feature of mitigating vibrations in a broad frequency range,it can be utilized in vibration reduction of tall structures.Here,partial differential equations governing a tall structure system motion were built,the analytic solutions of nonlinear normal modes were achieved by applying Galerkin＆#39;s method and Rauscher＆#39;s method.The nonlinear normal modal analysis revealed the vibration suppression principle of a NES absorber.The vibration characteristics of a NES-structure system were studied with varying of parameters of a NES absorber suing the nonlinear finite-element-method （FEM）. Results indicated that a NES absorber has optimal parameters,with those the structure vibration is greatly suppressed,the structure vibration with a NES absorber is reduced to 20% of the original one without a NES absorber,i.e.,80% of the vibration is suppressed;the empirical formula proposed is capable of predicting the optimal cubic stiffness values of a NES absorber,the value agree well with those obtained via FEM.