Adaptive multi-mode resonant piezoelectric shunt damping

doi:10.1088/0964-1726/13/5/007 Multiple-modes of structural vibration can be suppressed through the connection of an electrical impedance to the terminals of a bonded piezoelectric transducer. The so-called resonant shunts, one commonly used classofshunt impedances, provide good nominal damping performance but they are highly sensitive to variations in transducer capacitance and structural resonance frequencies. This paper introduces a new technique for the online adaptation of multi-mode resonant shunts. By minimizing the relative phase difference between a vibration reference signal and the shunt current, circuit component values can be optimally tuned online. Experiments on a cantilever beam validate the proposed technique and demonstrate the simplicity of implementation. The adaptive law converges quickly and maintains optimal performance in the presence of environmental uncertainties. 1.