Optimization and Experimental Validation of Hybrid Electromagnetic Shunt Damping for Enhanced Vibration Isolation

It is well known that electromagnetic shunt damper (EMSD) can generate substantial damping forces with relatively small shunt voltages and exhibit dynamic characteristics similar to those of a tuned vibration absorber in a single-degree-of-freedom (SDOF) system. However, their vibration-isolation performance is constrained by the intrinsic damping limitations of electronic components and typically requires negative-resistance (NR) shunt circuits to enhance damping efficiency and control performance. Such circuits, however, are prone to inducing system instability. To overcome these limitations, this study proposes a hybrid electromagnetic shunt damper (HEMSD) that integrates active control with passive shunting, enabling adjustable damping and unconditional stability without negative resistance. Based on a dimensionless SDOF vibration-isolation model, closed-form optimal parameters are derived for the undamped system under the [Formula: see text] optimization criterion. An adaptive simulated annealing particle swarm optimization (ASAPSO) algorithm is further employed to optimize the damped system and reveal the coupling mechanism between control gain and resistance ratio. The proposed method is experimentally validated on an SDOF vibration-isolation platform, showing excellent agreement between theoretical predictions and experimental measurements. The results confirm that the HEMSD exhibits superior low-frequency isolation capability and robust stability, providing a solid theoretical and practical foundation for the design of next-generation high-performance vibration-isolation systems.