Influence of Piezo-Actuator Thickness on the Active Vibration Control of a Cantilever Beam

The effect of piezo-actuator thickness on the active vibration control of a cantilever beam is investigated. The vibration field of the beam is theoretically estimated using the Euler-Bernoulli beam theory. Based on a static analysis, it is shown that there exists an optimal piezo-actuator thickness which maximizes the static beam deflection. Results indicate that the optimal thickness is a strong function of the Young's modulus ratio of the actuator/beam configuration, becoming thinner with stiffer piezo-actuators. For comparison, strategies for choosing piezo-actuator thickness based on a dynamic analysis are also investigated. Results suggest that the thickness choice for near-resonance excitation is similarly determined with the static analysis assuming structural damping. It is shown that lighter and stiffer piezo-actuators generally perform better. It is also shown that there exists a piezo-actuator thickness which maximizes the beam deflection for off resonance excitation with single-sided piezo-actuator configuration, which becomes thinner with stiffer and heavier piezo-actuators. In contrast, for double-sided piezo-actuator configuration, it is shown that the beam vibration response increases asymptotically to a limiting value as the piezo-actuator thickness approaches infinity. Parts of the theoretical results are verified with experiments.