Broadband vibration control of a structure by using a magnetorheological elastomer-based tuned dynamic absorber

A passive dynamic vibration absorber (DVA) is a mass-spring system that suppresses the vibration of a structure at a particular frequency. The DVA is especially effective when its excitation frequency is close to its tuned frequency. Fixing the physical properties of the DVA limits the application to a narrowband, harmonically excited vibration problem. A frequency-tunable DVA that can modulate its stiffness provides adaptability to the vibration control device against non-stationary disturbances. In this paper, we suggest a broadband frequency-tunable DVA whose natural frequency can be extended to more than 300% of the base value by using magnetorheological elastomers. We first conducted a magnetic field analysis by using a finite element method, through which the formation of a strong magnetic field within the core was observed. By taking full advantage of the frequency adjustability of the proposed DVA, we evaluated the real-time vibration control performance for an acoustically excited plate having multiple resonant peaks. The results show that the vibration of the structure can be effectively reduced with an improved performance by using a DVA instead of a passive absorber.