A new magnetostrictive-driven hydraulically amplified isolator for microvibration isolation

This paper presents the design, modeling, optimization, and experimental validation of a new magnetostrictive-driven hydraulically amplified isolator (MDHAI) for precision microvibration isolation. The proposed isolator integrates a giant magnetostrictive actuator (GMA) with a hydraulic amplification stage and an orifice-based damping path to extend the available actuation stroke and improve passive resonance suppression under low-frequency base excitation. A reduced-order nonlinear dynamic model is established to capture magnetostrictive hysteresis, hydraulic damping, and structural stiffness. The damping-orifice geometry is then optimized using a weighted multi-objective design procedure. Experimental results show that the MDHAI achieves an output displacement of ±100 μm and markedly improved vibration isolation performance under both harmonic and random excitation. In the harmonic tests, the displacement transmissibility peak is reduced to −9.8 dB, corresponding to a reduction of 22.2 dB relative to the standalone GMA. In the random-vibration tests, the RMS acceleration isolation efficiency reaches 85.3%, compared with 37.1% for the standalone GMA. These results demonstrate that the proposed MDHAI provides a practical solution for compact precision-payload isolation requiring both extended actuator stroke and enhanced microvibration attenuation.