两自由度非线性吸振器在简谐激励下的振动抑制

 为了分析两自由度(2-DOF)非线性吸振器(NES)在主共振附近产生周期及非周期响应时的振动抑制效果,首先应用复变量-平均法,推导了线性主结构连接一个2-DOF NES的系统在主共振附近的慢变力学模型,并对系统平衡点的稳定性进行了分析,进一步对系统响应类型进行了预测。然后,应用增量谐波平衡(IHB)法,对系统的慢变模型进行了数值验证。之后,对系统在稳态响应段及强调制响应(SMR)段的振动抑制效果进行了比较。最后研究了该系统在激励频率小幅变化时的振动抑制效果,并同单自由度(SDOF)NES进行了比较。仿真结果表明,2-DOF NES在强调制响应段的振动抑制效果更好,并且得到了比同质量优化后的S-DOF NES更好的振动抑制效果。

Vibration Suppression of a Two-degree-of-freedom Nonlinear Energy Sink Under Harmonic Excitation

Vibration suppression in the vicinity of the main resonance of a two-degree-of-freedom(2-DOF) nonlinear energy sink(NES) is investigated.The effectiveness of the 2-DOF NES is studied at both the periodic and quasi-periodic response regimes.Slow dynamics of a linear oscillator coupled with a 2-DOF small mass NES is established using the complex-averaging method.Stability of fixed points is investigated and a strongly modulated response(SMR) regime is found.The slow dynamics of the system is verified by the incremental harmonic balance(IHB) method,and the efficiency of vibration suppression at both periodic and strongly modulated response regimes are compared.Finally,the efficiency of vibration suppression is also compared with an equal-mass single-DOF(SDOF) NES which is optimally tuned.The simulation results show that the efficiency of vibration suppression can be enhanced by the 2-DOF NES when strongly modulated response occurs,and better performance of vibration suppression is observed compared to the same-mass SDOF NES.