An electromechanical surface damping (EMSD) technique is proposed. This technique combines two surface damping methods, the shunted piezoelectric-ceramic damping with the viscoelastic constrained layer damping (CLD). The damping contribution of the shunted piezoelectric intends to enhance the effective frequency range of the CLD. Piezoelectric ceramics provide similar damping characteristics to viscoelastic material when they are shunted with resonant electrical networks. A resonant shunting circuit provides the opportunity of tuning (shifting) the effective damping range of the piezoelectric into an arbitrary frequency, enhancing the damping at the vicinity of such frequency. Also, the EMSD technique proposes the use of a multiple resonant network to shunt the piezoelectric ceramic. This concept enhances simultaneously the effective damping range at the vicinity of multiple and selected frequencies. This thesis assesses the dynamic behavior of a simple structure under EMSD treatment and it studies the effectiveness of multiple tuning also. A cantilever beam-like structure is adopted as a case study and a typical oscillator with two resonant networks has been selected to shunt the piezoelectric-ceramic. A viscoelastic material is attached on the structure and constrained by the piezoelectric ceramic. The EMSD is tuned to two natural frequencies of the main structure and its effectiveness in suppressing two vibration peaks simultaneously is evaluated. This study provides insight into the use of shunting networks of higher order. The constitutive equations of the EMSD differential element are developed and a finite element solution is obtained. Finally, the EMSD is optimized to find effective tuning parameters.
Library of Congress Subject Headings
Damping (Mechanics); Vibration--Control; Piezoelectric ceramics; Electric networks
Velazquez, Carlos, "Electromechanical surface damping combining constrained layer and shunted piezoelectric matetrials with passive electrical networks of second order" (1995). Thesis. Rochester Institute of Technology. Accessed from
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