Design, Experiment and Verification of Resonant Frequency-Tunable Vibration Isolator Based on Annular Metal Rubbers and Shape Memory Alloy Actuators

Abstract

Detrimental vibration makes aircraft and spacecraft vulnerable to structural damage and payload instability. Traditional vibration isolator with sole resonant frequency risks to amplify vibrations whose frequencies are close to the resonant frequency of the vibration isolator, ending up in complex conundrums in the domain of aeronautics and astronautics. This research prompts to provide a universal solution to this conundrum by putting forward a vibration isolator capable of self-tuning its resonant frequency. The conception, design, and frequency tunability verification experiments were hence implemented in this research. Annular metal rubbers with different parameters were prepared and experimentally analyzed to determine the appropriate choice for resonant frequency tuning. It was discernible that both the increase of wire diameter and the relative density ratio of the metal rubbers could confer an augmentation of resonant frequency on the vibration isolator. The resonant frequency tuning was conducted by shape memory alloy actuators applying compressive loads to annular metal rubbers so as to change the stiffness of the isolator. The resonant frequency identification experiment demonstrated that the resonant frequency-tunable vibration isolator is versatile in resonant frequency tuning between 52 Hz and 113 Hz. The resonant frequency tunability ensures the avoidance of vibration amplification, improvising an ultimate solution to broad-banded vibration attenuation problems ranging from low frequency to high frequency vibration (e.g. 100 Hz) in aeronautical and astronautical environments.