In order to improve the harsh dynamic environment experienced by heavy rockets during different external excitations, this study presents a novel active variable stiffness vibration isolator (AVS-VI) used as the vibration isolation device to reduce excessive vibration of the whole-spacecraft isolation system. The AVS-VI is composed of horizontal stiffness spring, positive stiffness spring, parallelogram linkage mechanism, piezoelectric actuator, acceleration sensor, viscoelastic damping, and PID active controller. Based on the AVS-VI, the generalized vibration transmissibility determined by the nonlinear output frequency response functions and the energy absorption rate is applied to analyze the isolation performance of the whole-spacecraft system with AVS-VI. The AVS-VI can conduct adaptive vibration suppression with variable stiffness to the whole-spacecraft system, and the analysis results indicate that the AVS-VI is effective in reducing the extravagant vibration of the whole-spacecraft system, where the vibration isolation is decreased up to above 65% under different acceleration excitations. Finally, different parameters of AVS-VI are considered to optimize the whole-spacecraft system based on the generalized vibration transmissibility and the energy absorption rate.

为了改善重型火箭在不同的外部激励下所经历的恶劣动态环境，本研究提出了一种新型的主动变刚度隔振器（AVS-VI）作为隔振装置，以减少整个航天器隔振系统的过度振动。AVS-VI由水平刚度弹簧，正刚度弹簧，平行四边形连杆机构，压电致动器，加速度传感器，粘弹性阻尼和PID主动控制器组成。基于AVS-VI，利用非线性输出频率响应函数和能量吸收率确定的广义振动传递率，用于分析AVS-VI对整个航天器系统的隔振性能。AVS-VI可以对整个航天器系统进行可变刚度的自适应振动抑制，分析结果表明，AVS-VI可以有效地减小整个航天器系统的多余振动，从而减少了隔振。在不同的加速度激励下达到65％以上。最后，基于广义振动传递率和能量吸收率，考虑了AVS-VI的不同参数来优化整个航天器系统。