Design and Experimental Study of a Multiple-Degree-of-Freedom Vibration Absorber by Using an Inertial Actuator

It is well known that the inertial actuator can be used as the passive vibration absorber if the natural frequency of the inertial actuator is closed to the targeted structural resonance frequency. Typically, the inertial actuator as a passive or semi-active vibration absorber can only control a single structural resonance at a time. In this study, a simple and practical multiple-degree-of-freedom (MDOF) vibration absorber, which is based on a single inertial actuator and a parallel connection of multiple low-pass filters as controller, is proposed to damp multiple structural resonances simultaneously. The control performance of the proposed MDOF vibration absorber is the combined control effects for both passive absorber and active absorber. It means that the multiple-mode structural vibration can be reduced effectively by using a single inertial actuator. Additionally, the proposed controller can be designed by low-cost analogue circuit and allows directly using acceleration feedback. The performance of the MDOF vibration absorber is first analyzed both numerically and experimentally. Then the proposed MDOF vibration absorber is applied to control the vibration of multiple resonances of a cantilever beam. The experimental results show that multimodal damping can be generated by the proposed MDOF vibration absorber.