基于可控电磁负刚度的半主动隔振器传递率特性研究

Transmissibility characteristics of semi-active vibration isolator based on controllable electro-magnetic negative stiffness

针对传统隔振器刚度不可调的缺陷,提出了一种新型的基于负刚度调控的半主动隔振器,通过研究绝对位移传递率特性评估其刚度可控性和隔振性能。基于场论和等效磁荷法建立了电磁负刚度的理论计算公式,该公式与激励电流呈现函数关系;由于电磁负刚度计算的复杂性,用最小二乘法对负刚度计算公式进行了近似;基于负刚度的近似表达,建立了正负刚度并联的半主动隔振器,分析了励磁电流对传递率和阻尼率的影响规律。试验验证了线性条件下电流对隔振器传递率作用的规律。

Here,aiming at the defect of traditional vibration isolator’s stiffness being not adjustable,a new semi-active vibration isolator based on negative stiffness control was proposed,and its stiffness controllability and vibration isolation performance were evaluated through studying characteristics of absolute displacement transmissibility.Firstly,based on the field theory and the equivalent magnetic charge method,the theoretical calculation formula for electromagnetic negative stiffness was established,and there was a function relation between this formula and excitation current.Secondly,due to the complexity of electromagnetic negative stiffness calculation,the negative stiffness calculation formula was approximated with the least square method.Furthermore,based on the approximate expression of negative stiffness,a semi-active vibration isolator with positive and negative stiffnesses in parallel was established to analyze effect law of excitation current on the isolator’s transmissibility and damping ratio.Finally,the current effect law on the isolator transmissibility under linear conditions was verified with tests.