Construction and characterization of removable and reusable piezoelectric actuators
Piezoelectric patch-type actuators are being considered for use in acoustic control and vibration control of complex mechanical structures such as aircraft fuselages and automobile interiors. For complex structures, it is often difficult to predict the best location of actuator-structure interaction. Currently, piezoelectric patch-type actuators are bonded permanently to the host structure using a technique that requires surface preparation. This technique is not well suited for actuator performance testing and model verification since attaching the actuator is time-consuming, removing the actuator is difficult, and the actuator is destroyed when it is removed.
We present three alternate techniques for bonding flat piezoelectric patch-type actuators to structures. These techniques allow the actuator to be attached quickly, removed easily, and reused. The alternate techniques and a permanent bonding technique are used to attach actuators to a clamped-free beam. For each attachment technique, we obtain the frequency response functions, actuator authority levels, and damping ratios. We also obtain the degradation of the actuator authority and damping ratio as the actuator is reused. For each attachment technique, we compare the measured performance to the performance predicted from a pin-force model of that actuator attachment.
The attachment techniques that allowed us to make removable, reusable piezoelectric actuators were shown to provide structural actuation very similar to actuation provided by permanently attached piezoelectric actuators. A small but statistically significant change in authority occurred as a result of removing the actuator. The confidence intervals of actuator authority increased in frequency regions of antiresonance and closely spaced modes. The pin-force model did not provide an accurate analysis method for predicting actuator authority.