Enhanced low-frequency vibration suppression with a active quasi-zero-stiffness absorber

Dynamic vibration absorbers (DVAs) are widely used to significantly reduce vibrations in primary systems. Among these, active dynamic vibration absorbers (ADVAs) stand out due to their ability to suppress vibrations over a broad frequency spectrum. The development of an optimal attenuation strategy for such absorbers under variable ultra-low frequency excitations is crucial for maximizing the performance of the primary system. This paper presents an innovative active quasi-zero-stiffness (AQZS) dynamic vibration absorber (DVA) for effective vibration suppression across ultra-low frequencies. The AQZS DVA utilizes the principle of quasi-zero-stiffness dynamic vibration absorption and is integrated with an electromagnetic actuator to provide tunable vibration attenuation. The theoretical analysis of the AQZS DVA’s restoring force confirms its quasi-zero-stiffness feature. Furthermore, a nonlinear sliding mode control strategy is developed to actively regulate the AQZS DVA, with the Lyapunov stability criterion ensuring convergence of the system. The study systematically examines the effects of various parameters on the vibration attenuation performance of the primary system through a tuning process for the AQZS DVA. Experimental validation of the prototype demonstrates that the nonlinear sliding mode control significantly enhances the vibration suppression efficiency. The findings indicate that the AQZS DVA system is a promising solution for vibration attenuation in the ultra-low frequency range.