考虑载荷变化的准零刚度隔振器动态特性

Dynamic Analysis of Quasi-Zero-Stiffness Vibration Isolator Considering Load Variation

为了研究载荷变化对准零刚度隔振器动态特性及隔振性能的影响,首先,分析具有分段非线性特性的准零刚度隔振器静力学特性;其次,引入光滑函数,应用增量谐波平衡法得到准零刚度隔振器的周期解,分析载荷与激励幅值对隔振器动态特性的影响;最后,定义准零刚度隔振器的力传递率,分析载荷与激励幅值对其隔振性能的影响。研究结果表明:当激励幅值较大时,载荷变化会导致响应的常数项在共振区附近出现交叉折叠的现象;载荷与激励幅值的变化会改变隔振系统的共振频率、传递率峰值以及有效隔振频带,但该准零刚度隔振器的隔振性能仍优于线性隔振器。

In order to investigate the effect of load variation on the quasi-zero-stiffness(QZS)vibration isolator,firstly,the statics of a QZS vibration isolator with piecewise nonlinear characteristic is analyzed.Then,the smoothing function is introduced here and the periodic solutions of the QZS vibration isolator are obtained using incremental harmonic balance(IHB)method.The effects of load and excitation ampli-tude on the dynamic characteristics are studied.Finally,the force transmissibility of the QZS vibration isolator is defined.And the effects of load and excitation amplitude on the isolation performance are investigated.The results show that the cross and folding phenomenon occurs in the constant term of the amplitudefrequency curves near the resonance region when the excitation amplitude is relatively large;The variations of load and excitation amplitude lead to the changes of resonance frequency,peak value of transmissibility and vibration isolation frequency band.However,the QZS vibration isolator still outperforms the corresponding linear counterpart.