时滞阻尼液固混合介质隔振系统的动力学研究

针对单一线性阻尼被动隔振无法兼顾共振区与隔振有效区的隔振性能问题,提出了时滞立方非线性主动阻尼控制策略。以具备分段线性刚度液固混合介质受控隔振系统为研究对象,运用多尺度摄动法对受控系统进行主共振分析,建立了等效刚度和等效阻尼的概念,并考察时滞对受控系统幅频特性与传递率特性的影响。研究结果表明:由于主动时滞的引入,立方非线性速度反馈增益既可调控阻尼,还可以调整隔振系统的等效刚度;与单一线性阻尼相比,立方速度反馈在不改变隔振有效区隔振效果的同时,显著降低了共振区的传递率;对于因鞍结分岔在主共振造成的幅值跳跃,通过选择合适的反馈时滞可以有效抑制跳跃的出现;通过稳定性分析发现,受控系统并非是全时滞稳定,因此最后给出控制器中反馈增益和时滞的参数区间设计方法。

Dynamics of SALiM Vibration Isolation System with the Active Time-Delay Damping

To overcome the problem that the vibration isolation performance between the resonance region and the vibration isolation effective region can not be balanced by the passive vibration isolation technique, the active nonlinear damping control strategy with the inherent time delay is proposed. Firstly, the multi-scale perturbation method is applied to investigate the primary resonance for the examined time-delay active damping isolation system, which possesses the piecewise bilinear stiffness. Then the concepts of equivalent stiffness and damping are established, and effects of the time delay on the amplitude frequency characteristics of the controlled system are investigated. As a result, it can be seen that by choosing the proper feedback gain, the saddle-node bifurcation can be effectively suppressed, and the occurrence of jumping phenomenon can be avoided as well. At last, according to the response stability analysis, the parameter intervals for feedback gain and beneficial time delay are given.