Dynamic Vibration Absorber

About: Dynamic Vibration Absorber is a research topic. Over the lifetime, 4764 publications have been published within this topic receiving 49429 citations.

Energy-Recycling Semi-Active Method for Vibration Suppression with Piezoelectric Transducers

Abstract: *A novel energy-recycling method is studied that enables effective semi-active vibration suppression with piezoelectric transducers embedded or bonded to a structure. In this method, the energy converted from the mechanical energy of a vibrating structure is collected in the capacitor of a piezoelectric transducer as an electric charge, and to suppress vibration, rather than dissipate the energy, the polarity of the charge is changed according to the state of vibration. With this method, no energy is supplied to the total system of the structure and transducers with shunt circuit, which means that the system is stable. A simple electric circuit and a control law for multiple-degree-offreedom systems with multiple piezoelectric transducers are proposed for this method based on energy recycling. Numerical simulation of vibration suppression of a truss structure shows that this method is more effective in suppressing vibration than both a semi-active method without energy-recycling and that based on the use of an optimally tuned passive system. A preliminary experiment with a truss structure also shows that this method can effectively suppress vibration in an actual structure. However, there was some discrepancy in the experimental results compared to the results of the numerical simulation performed assuming ideal linear characteristics of the piezoelectric transducers estimated from a static test. Nomenclature

The Two-Degree-of-Freedom Tuned-Mass Damper for Suppression of Single-Mode Vibration Under Random and Harmonic Excitation

Abstract: Whenever a tuned-mass damper is attached to a primary system, motion of the absorber body in more than one degree of freedom (DOF) relative to the primary system can be used to attenuate vibration of the primary system. In this paper, we propose that more than one mode of vibration of an absorber body relative to a primary system be tuned to suppress single-mode vibration of a primary system. We cast the problem of optimization of the multi-degree-of-freedom connection between the absorber body and primary structure as a decentralized control problem and develop optimization algorithms based on the H2 and H-infinity norms to minimize the response to random and harmonic excitations, respectively. We find that a two-DOF absorber can attain better performance than the optimal SDOF absorber, even for the case where the rotary inertia of the absorber tends to zero. With properly chosen connection locations, the two-DOF absorber achieves better vibration suppression than two separate absorbers of optimized mass distribution. A two-DOF absorber with a negative damper in one of its two connections to the primary system yields significantly better performance than absorbers with only positive dampers.