基于频变阻尼特性的四参数隔振系统建模与参数分析

Modeling and parameter analysis of a four-parameter isolation system based on frequency-dependent damping characteristics

随着航天技术的快速发展,航天器中的有效任务载荷对隔振器的可靠性、稳定性要求不断越高。为了解决传统被动隔振器中低频与高频隔振性能之间的矛盾,亟需一种能够实现低频大阻尼、高频小阻尼的频变隔振系统。基于现有的三参数模型,提出一种具有频变阻尼特性的四参数隔振系统;通过归一化参数,建立系统数学模型,分析各参数对系统性能的影响。针对建立的理论计算模型,利用Simulink进行仿真验证,相较于被动隔振系统,四参数系统能够将7 Hz固有频率处的传递率幅值降低28.85 dB,证明低频大阻尼效果显著;同时,采用100 Hz正弦信号激励时,时域幅值衰减率达99.5%,证明高频小阻尼作用凸显,从而验证了四参数系统具有频变阻尼特性,即低共振峰值和良好的高频隔振性能。

With the rapid development of aerospace technology,the effective mission load in spacecraft has continuously higher requirements for reliability and stability of vibration isolators.In order to solve contradictions between low-frequency and high-frequency isolation performance in traditional passive isolators,a frequency-dependent isolation system that can achieve large damping at low frequencies and small damping at high frequencies is urgently needed.A four-parameter isolation system with frequency-dependent damping characteristics was proposed based on an existing three-parameter model.The mathematical model was established and influences of each parameter on system performance were analyzed.For established the theoretical model,Simulink was used for verification.Compared with the passive isolation system,it was shown that the four-parameter system can reduce the transmission rate amplitude at 7 Hz natural frequency by 28.85 dB;using 100 Hz sine signal excitation,the time-domain amplitude attenuation rate reaches 99.5%;the four-parameter system has low resonance peak and good high-frequency isolation performance.